Ads-b and sailplanes [Archive]

Darryl Ramm

March 26th 15, 10:46 AM

On Wednesday, March 25, 2015 at 8:01:26 PM UTC-7, Andrew Ainslie wrote:
> Well, I have indeed discovered that you have strong opinions on the topic, and are able to command an impressive array of acronyms that it'd take me hours to google. Care to offer a newbie more than a dismissive flame?

ADS-B Out GPS sources no longer need to be explicitly TSO'ed, they do need to "meet requirements of" the relevant TSO. That does not mean that any old random GPS will do. In fact no consumer GPS or any GPS with a NMEA output would be acceptable. The "RAIM" claims by GRT Avionics do not mean that GPS receiver "meet the performance requirements" of the relevant IFR GPS TSO.... it could not as is (since it only appears to communicate via NMEA), I expect they are doing some proprietary RAIM signalling to their own EFIS boxes. Who knows. Unless vendors are quoting exact TSO or RTCA specs things like saying the GPS has "WAAS" or "RAIM" become fairly useless marketing terms..

And that does not mean that an install in a certified aircraft (including glider) will not require a TSO'ed GPS. That minor wording change was mostly a win for the experimental powered aircraft folks, many of those owners will need to meet the 2020 ADS-B Out carriage mandate, and can now do so with non-TSO'ed GPS sources that "meet the performance requirements of...".

It has always been the case that in an experiential aircraft can install a non-TSO (and non-meets performance of...) GPS source for ADS-B Out as long as all the basic things are done right and the aircraft correctly transmits the appropriate SIL parameters to advertise it is using a non-complaint GPS source. However that will *not* meet the 2020 carriage mandate, and allow that aircraft to fly in airspace requiring ADS-B Out (again which glider are largely exempt from). And that "non-compliant" ADS-B Out carriage may or may not (it appears that it often does) result in the FAA ADS-B ground infrastructure today providing ADS-R and TIS-B service for that aircraft (in the hockey pucks around the aircraft you referred to), or certified airborne ADS-B receivers seeing that aircraft. And that situation may change (i.e. worsen) in future.

Your goal of wanting to have some aircraft flying around with ADS-B out so it would activate the FAA ground station based ADS-R and TIS-B services for nearby aircraft might seem attractive but is likely not useful at best, or a dangerous idea at worst. It's not useful if you expect the other aircraft to be gliders equipped with PowerFLARM receivers, as PowerFLARM does not receive ADS-R or TIS-B transmissions. Even if you had gliders equipped with suitable ADS-B receivers you still have the problems that ADS-R and TIS-B service volumes are are pretty shallow (e.g. +/- 3.500' for TIS-B) and you get the very bad traffic warning situation where if your aircraft is not equipped with ADS-B Out then you see traffic on your ADS-B In traffic display only near other ADS-B Out equipped aircraft, and once the traffic flys away from those other ADS-B out equipped aircraft, possibly towards you, they can drop off the traffic display. There is *no* way a pilot can look at any ADS-B traffic display and try to reverse engineer in their mind what is going on, what traffic is being painted for what client aircraft etc. You could help encourage very dangerous situations where pilots start thinking their ADS-B receiver can see/warn about traffic, and then all of a sudden the traffic actually a threat to them becomes invisible. If your glider is airborne and a client for ADS-R and TIS-B and you descent below service coverage (which might be pattern altitude or higher)then all of a sudden and with no warning to other pilots all TIS-B and ADS-R traffic show on all displays on all aircraft in that area could just disappear. If you want to use ADS-R and TIS-B safely you *need* ADS-B Out in your aircraft. That is just how the broken system was designed to work. The saving grace is hopefully most aircraft will equip with 1090ES Out, in which case any PowerFLARM unit will "see" them, independent of any ADS-B ground infrastructure/line of sight, radar coverage or having the glider ADS-B Out equipped.

So again, we get back to the old simple advice that if you fly gliders near busy airspace and are worried about running into fast jets and airliners etc. then by far the most effective technology related thing you can do is install a transponder... and it is fantastic to see you have. The 1090ES In part of a PowerFLARM can help point out some airliner/fast jet/high-end GA traffic to you, but especially with fast traffic you want them seeing/avoiding you with TCAS, and that takes a transponder. If you are worried about GA aircraft then the combination of a transponder and the PCAS part of PowerFLARM can be pretty useful.

All this stuff has been hashed out in other threads here before. If you don't understand much of this stuff or can't spend time Googling acronyms and working out what things means then you probably should not be worried about trying to be at the bleeding edge of this technology. It can be expensive to play with today, rapidly changing from a product viewpoint, and is just a technical and regulatory mess. Far too much crap for the average glider pilot to want to deal with. It is great that you already have a transponder installed in your glider, but now you spent $600 on a GPS receiver that will do nothing more for you techncially than any decent consumer/WAAS receiver, or just connecting to the NMEA out from a PowerFLARM (which I also hope you already have). Sure you can install this in your experimental category glider (you always could, even before the changed CFR14 wording you are referring to) with the appropriate SIL settings. It won't get you any closer to meeting 2020 carriage requirements (which was not your goal). And it *may* (apparently *should* at least today) trigger FAA TIS-B and ADS-R ground based services for your aircraft if you are in range of those ground stations (and you also have to correctly configure the CC/Capability Code bits in the Trig for it to advertise the aircraft has an ADS-B receiver and on what link layer).... but if your ADS-B receiver is a PowerFLARM it can't receive ADS-R or TIS-B to begin with, but it will keep seeing the 1090ES Out equipped traffic it is already seeing....

Bob Pasker

March 26th 15, 01:19 PM

from AC 20-165A:

>>> (c) The ADS-B equipment can only allow an anonymous 24-bit address selection if
the Mode 3/A code is set to 1200

I wonder if they will add 1202 as well (see http://www.faa.gov/documentLibrary/media/Notice/N7110.577.pdf)

Darryl Ramm

March 26th 15, 05:16 PM

No they will not. This was done to largely placate AOPA and others who lobbied the FAA. Those organizations really should have been worrying more about fundamental issues with how broken the whole dual link approach is.... Instead of stuff like this or prioritizing keeping aging Mode C transponders in use. And the anonymous mode only applies to UAT Out. Any 1090ES capable transponder is already transmitting the aircraft's ICAO address and that cannot be disabled (try it and you will likely get a visit from the FAA). And if glider owners ever want to install any of this mess it is 1090ES Out not UAT out they should install -- for compatibility with PowerFLARM, and since you need a transponder anyhow for TCAS compatibility.

Darryl Ramm

March 26th 15, 05:24 PM

Oops somehow the opening few words of my first paragraph that should have started with "To meet the 2020 carriage mandate ..." Got deleted,

Andrew Ainslie

March 26th 15, 09:32 PM

Thank you for the explanation, Darryl. I appreciate the time you put into your commentary.

Bill T

March 27th 15, 01:24 AM

Thanks!
Just trying to keep up with the development of systems and processes, and not be last in line in 2019 at the avionics shop.
BillT

John Carlyle

April 2nd 15, 03:07 PM

Darryl,

Question regarding your statement that gliders are largely exempt from needing ADS-B Out to fly in 2020 inside some airspace which requires ADS-B Out.

I'm based inside a Mode C Veil. My glider has a TT21 equipped with the latest firmware 2.4 and 1.10 (I also have a PowerFlarm core providing ADS-B In).. Come 2020, since I have a Mode S transponder, I think I'll be required to install a C145a GPS that is known to work properly with my TT21.

Do you agree?

-John, Q3

On Thursday, March 26, 2015 at 6:46:08 AM UTC-4, Darryl Ramm wrote:
--snip--
> It has always been the case that in an experiential aircraft can install a non-TSO (and non-meets performance of...) GPS source for ADS-B Out as long as all the basic things are done right and the aircraft correctly transmits the appropriate SIL parameters to advertise it is using a non-complaint GPS source. However that will *not* meet the 2020 carriage mandate, and allow that aircraft to fly in airspace requiring ADS-B Out (again which glider are largely exempt from).
--snip--

Bill T

April 3rd 15, 01:42 AM

John, I'm sure Darryl will be along shortly.
Gliders are not required to have a transponder or ADS-B Out.
You are not required to add Out GPS data to the Trig unless you chose to. But if you do it must meet the standards.
FAA has recently reworded the language that allows "Experimental" kit built aircraft to install non TSO'd ADSB out systems as long as they meet the same standards. I'm not sure if that applies to experimental gliders.

We have Trig21 on some of our gliders, inside the Mode C Veil, we are not planning to add GPS to the Trig.
BillT

Darryl Ramm

April 3rd 15, 02:36 AM

On Thursday, April 2, 2015 at 5:42:12 PM UTC-7, Bill T wrote:
> John, I'm sure Darryl will be along shortly.
> Gliders are not required to have a transponder or ADS-B Out.
> You are not required to add Out GPS data to the Trig unless you chose to. But if you do it must meet the standards.
> FAA has recently reworded the language that allows "Experimental" kit built aircraft to install non TSO'd ADSB out systems as long as they meet the same standards. I'm not sure if that applies to experimental gliders.
>
> We have Trig21 on some of our gliders, inside the Mode C Veil, we are not planning to add GPS to the Trig.
> BillT

Bill is right. You won't need to do this, not unless the regulations are changed, and that would be a huge surprise.

You need to read 14 CFR 91.225.

Because of the the glider/electrical system exemption you can fly within a Mode C Veil after 2020 without ADS-B Out. Obviously when that close to lots of traffic I'd hope glider owners do equip their aircraft with a transponder, as you have--thanks! And that transponder provides lots of protection, importantly it makes you visible to the TCAS systems in just about all airliners and fast jets.

If you chose to install ADS-B Out and your glider is certified then you must meet all the requirements of the 2020 ADS-B Out Mandate, that unfortunately is not something that a Trig TT-21 transponder can do, you need to have a TT-22 because of FAA's silly power requirements for ADS-B Out. And yes you would also likely need a TSO-C145a (or later) GPS source. If your glider is experimental then you have cheaper options (but you need to be careful that say if you connect a commodity GPS to the Trig it won't give you any post 2020 mandate privilege e.g. not allow your glider to enter class B or C airspace... probably not an issue :-)).

John Carlyle

April 3rd 15, 03:23 PM

BillT, Darryl, thanks for your replies. I really got confused with 14 CFR 91.215 and 91.225! I reread them again, and now I see where I went wrong.

It's nice that I won't have to spring for an expensive C145a GPS source. My glider is experimental so I do have the option to feed it with the PowerFlarm GPS. I won't ever be going into Class B or C airspace, though, so I'm not sure what I'd gain by implementing ADS-B Out via this option.

A question regarding TCAS - it calculates target range using reply timing rather than received power level, doesn't it? In other words, TCAS doesn't work like the PowerFlarm or Zaon PCAS, so I don't have to worry about getting too close to airliners because I have a 130W instead of a 250W transponder.

-John, Q3

On Thursday, April 2, 2015 at 9:36:07 PM UTC-4, Darryl Ramm wrote:
> On Thursday, April 2, 2015 at 5:42:12 PM UTC-7, Bill T wrote:
> > John, I'm sure Darryl will be along shortly.
> > Gliders are not required to have a transponder or ADS-B Out.
> > You are not required to add Out GPS data to the Trig unless you chose to. But if you do it must meet the standards.
> > FAA has recently reworded the language that allows "Experimental" kit built aircraft to install non TSO'd ADSB out systems as long as they meet the same standards. I'm not sure if that applies to experimental gliders.
> >
> > We have Trig21 on some of our gliders, inside the Mode C Veil, we are not planning to add GPS to the Trig.
> > BillT
>
> Bill is right. You won't need to do this, not unless the regulations are changed, and that would be a huge surprise.
>
> You need to read 14 CFR 91.225.
>
> Because of the the glider/electrical system exemption you can fly within a Mode C Veil after 2020 without ADS-B Out. Obviously when that close to lots of traffic I'd hope glider owners do equip their aircraft with a transponder, as you have--thanks! And that transponder provides lots of protection, importantly it makes you visible to the TCAS systems in just about all airliners and fast jets.
>
> If you chose to install ADS-B Out and your glider is certified then you must meet all the requirements of the 2020 ADS-B Out Mandate, that unfortunately is not something that a Trig TT-21 transponder can do, you need to have a TT-22 because of FAA's silly power requirements for ADS-B Out. And yes you would also likely need a TSO-C145a (or later) GPS source. If your glider is experimental then you have cheaper options (but you need to be careful that say if you connect a commodity GPS to the Trig it won't give you any post 2020 mandate privilege e.g. not allow your glider to enter class B or C airspace... probably not an issue :-)).

Darryl Ramm

April 3rd 15, 07:16 PM

On Friday, April 3, 2015 at 7:23:35 AM UTC-7, John Carlyle wrote:
> BillT, Darryl, thanks for your replies. I really got confused with 14 CFR 91.215 and 91.225! I reread them again, and now I see where I went wrong.
>
> It's nice that I won't have to spring for an expensive C145a GPS source. My glider is experimental so I do have the option to feed it with the PowerFlarm GPS. I won't ever be going into Class B or C airspace, though, so I'm not sure what I'd gain by implementing ADS-B Out via this option.
>
> A question regarding TCAS - it calculates target range using reply timing rather than received power level, doesn't it? In other words, TCAS doesn't work like the PowerFlarm or Zaon PCAS, so I don't have to worry about getting too close to airliners because I have a 130W instead of a 250W transponder.
>
> -John, Q3
>
> On Thursday, April 2, 2015 at 9:36:07 PM UTC-4, Darryl Ramm wrote:
> > On Thursday, April 2, 2015 at 5:42:12 PM UTC-7, Bill T wrote:
> > > John, I'm sure Darryl will be along shortly.
> > > Gliders are not required to have a transponder or ADS-B Out.
> > > You are not required to add Out GPS data to the Trig unless you chose to. But if you do it must meet the standards.
> > > FAA has recently reworded the language that allows "Experimental" kit built aircraft to install non TSO'd ADSB out systems as long as they meet the same standards. I'm not sure if that applies to experimental gliders.
> > >
> > > We have Trig21 on some of our gliders, inside the Mode C Veil, we are not planning to add GPS to the Trig.
> > > BillT
> >
> > Bill is right. You won't need to do this, not unless the regulations are changed, and that would be a huge surprise.
> >
> > You need to read 14 CFR 91.225.
> >
> > Because of the the glider/electrical system exemption you can fly within a Mode C Veil after 2020 without ADS-B Out. Obviously when that close to lots of traffic I'd hope glider owners do equip their aircraft with a transponder, as you have--thanks! And that transponder provides lots of protection, importantly it makes you visible to the TCAS systems in just about all airliners and fast jets.
> >
> > If you chose to install ADS-B Out and your glider is certified then you must meet all the requirements of the 2020 ADS-B Out Mandate, that unfortunately is not something that a Trig TT-21 transponder can do, you need to have a TT-22 because of FAA's silly power requirements for ADS-B Out. And yes you would also likely need a TSO-C145a (or later) GPS source. If your glider is experimental then you have cheaper options (but you need to be careful that say if you connect a commodity GPS to the Trig it won't give you any post 2020 mandate privilege e.g. not allow your glider to enter class B or C airspace... probably not an issue :-)).

TCAS is it's own interrogator (so are the GA oriented "TCAD" systems, some of which evolved to be TCAS I certified), it measures other aircraft's response time to it's interrogations to measure slant distance, and it reads the transponder Mode C replies (or the Mode S equivalent) to get the other aircraft altitudes.

And those TCAS interrogators are one of the reasons why PCAS works at all in areas where you don't have line of sight to a ground based SSR interrogator to cause those transponders to reply... if you are anywhere near popular flight paths. Those TCAS systems are interrogating aircraft out to several tens of miles.

Bonus reading:

TCAS only ever issues Mode C interrogations (or Mode S equivalent), not Mode A for several reasons, one is there is just not much point--the aircrew don't need to know the other aircraft squawk code, and to just cut down on wasting bandwidth, and to avoid confusion about whether a reply from old Mode A/C transponders is a Mode C altitude or a Mode A squawk code.

TCAS II uses a crude predicted time to impact to prioritize threats and when to issue TA and RAs. As the threats get close the TCAS system gets "pretty interested" in the treat and will start hammering away with rapid transponder interrogations. TCAS II works intelligently using selective interrogation of Mode S transponders to cut down on wasting bandwidth. Enough Mode A/C equipped traffic near TCAS based interrogators wastes bandwidth with all the stupid Mode C interrogation replies. That is one reasons that I wish the FAA had said way back in the 1990s that Mode A/C would eventually go away and be replaced with Mode S only...give the industry a clear 1-2 decade roadmap. And that could have lead to a simpler, more affordable and more usable 1090ES only ADS-B system in the USA. Organizations like AOPA lobbying for keeping Mode A/C helped encourage the complex dual-link mess we ended up with.

[email protected]

April 3rd 15, 09:53 PM

I would expect that the PowerFlarm NMEA to Trig for ADSB Out will be a popular configuration for anyone with an experimental glider.

Other than making up a cable to go from the PowerFlarm to the remote unit on the Trig is there any testing requirement similar to the Biannual Transponder check that would be required?

Darryl Ramm

April 3rd 15, 10:22 PM

On Friday, April 3, 2015 at 1:53:32 PM UTC-7, wrote:
> I would expect that the PowerFlarm NMEA to Trig for ADSB Out will be a popular configuration for anyone with an experimental glider.
>
> Other than making up a cable to go from the PowerFlarm to the remote unit on the Trig is there any testing requirement similar to the Biannual Transponder check that would be required?

You are in the wild wild west. You are not meeting any requirement and so not required to do any additional tests that I am aware of besides maintaining the transponder biannual tests. But you better be damn sure to set the GPS SIL parameter and other information correctly... check with Trig and/or their dealers and/or your avionics shop to make sure you have the latest instructions on setting this up.

It will be interesting to see how long a range people see in practice between their Trig transponders with 1090ES Out and PowerFLARM 1090ES In. And 1090ES Out in gliders *might* get interesting for club/FBO/crew tracking.

The dual-link coverage mess with TIS-B and ADS-R is well a mess. If you have an ADS-B receiver capable of receiving TIS-B or ADS-R (like a Garmin ADS-B portable receiver) then you also need to set the appropriate ADS-B out capability code bits in the Trig. It really does not matter with a PowerFLARM since they can't receive ADS-R or TIS-B. I suspect the FAA would really prefer that not set unless you can really have that receive capability--but I'm not sure how seriously they would care. And at some time the threat seems to be non-compliant ADS-B Out won't trigger ADS-R and TIS-B services anyhow.

[email protected]

April 5th 15, 09:45 AM

Amazing how big a mess the FAA has made of the ADS-B thing isn't it? It seems like it had the potential to streamline things and provide useful situational awareness about other traffic with a relatively simple and inexpensive device - sort of a like a universal implementation of FLARM-like technology in all aircraft. So much for that.

My club held off on FLARM for a couple of years as some members thought that ADS-B would make it redundant. We're now installing it to club ships and the tow planes as funds allow and many of the privately owned gliders have it. In my case all it took was one flight to be convinced of the usefulness of FLARM and I was a bit skeptical of its value in our location at first.

Mike Schumann[_2_]

April 6th 15, 03:11 AM

On Sunday, April 5, 2015 at 4:45:31 AM UTC-4, wrote:
> Amazing how big a mess the FAA has made of the ADS-B thing isn't it? It seems like it had the potential to streamline things and provide useful situational awareness about other traffic with a relatively simple and inexpensive device - sort of a like a universal implementation of FLARM-like technology in all aircraft. So much for that.
>
> My club held off on FLARM for a couple of years as some members thought that ADS-B would make it redundant. We're now installing it to club ships and the tow planes as funds allow and many of the privately owned gliders have it. In my case all it took was one flight to be convinced of the usefulness of FLARM and I was a bit skeptical of its value in our location at first..

I wouldn't ignore ADS-B as the long term solution to the collision avoidance puzzle. It's almost inevitable that this technology will be the cornerstone of collision avoidance for UAVs that are going to start sharing our US airspace.

The confusion of having two standards (1090ES and UAT) is unfortunate. The FAA (and originally MITRE, which developed the UAT standard) had good intentions. UAT provided the bandwidth needed for the kind of system that would permit a proliferation of other new services far into the future. Conversely adding 1090ES to the Mode S transponder standards provided such limited bandwidth to support ADS-B that there was legitimate concern that this technology would not work in some of the high density US airspaces (NYC, Atlanta, and Chicago), if all commercial and GA aircraft were so equipped.

Standardization on UAT would have been the ideal solution. Unfortunately this did not happen due to the lack of availability of a common frequency thru-out the world and the reluctance of the international aviation community to support this standard. If the FAA had insisted on UAT as the North American standard, it would have dramatically simplified the whole system at the cost of requiring dual equipage on a relatively small number of airliners used on international routes.

For most GA and commercial aircraft, operating within range of ADS-B ground stations, the current mixed UAT / 1090ES environment works well. The big issue is the lack of reliable ADS-B ground station coverage for low altitude operations in remote areas.

However, even in these environments, the future looks promising. There are now low cost dual frequency ADS-B IN receivers on the market that receive both 1090ES and UAT signals. Within the next year or two, single band ADS-B receivers will probably disappear from the market, due to the low cost of the much superior dual band receivers.

The big question is whether POWERFLARM will evolve to fully support this emerging ADS-B environment by incorporating a dual band ADS-B receiver and/or supporting the ADS-B ground station TIS-B capability, or if it will become irrelevant by the introduction of new low cost ADS-B IN solutions designed for the much larger GA community, incorporating not only dual band receivers, but also more sophisticated collision avoidance algorithms that take into account non-typical GA traffic like gliders, parachutists, and balloons.

Darryl Ramm

April 6th 15, 08:35 AM

On 4/5/15 7:11 PM, Mike Schumann wrote:
> On Sunday, April 5, 2015 at 4:45:31 AM UTC-4, wrote:
>> Amazing how big a mess the FAA has made of the ADS-B thing isn't it? It seems like it had the potential to streamline things and provide useful situational awareness about other traffic with a relatively simple and inexpensive device - sort of a like a universal implementation of FLARM-like technology in all aircraft. So much for that.
>>
>> My club held off on FLARM for a couple of years as some members thought that ADS-B would make it redundant. We're now installing it to club ships and the tow planes as funds allow and many of the privately owned gliders have it. In my case all it took was one flight to be convinced of the usefulness of FLARM and I was a bit skeptical of its value in our location at first.
>
> I wouldn't ignore ADS-B as the long term solution to the collision avoidance puzzle. It's almost inevitable that this technology will be the cornerstone of collision avoidance for UAVs that are going to start sharing our US airspace.
>
> The confusion of having two standards (1090ES and UAT) is unfortunate. The FAA (and originally MITRE, which developed the UAT standard) had good intentions. UAT provided the bandwidth needed for the kind of system that would permit a proliferation of other new services far into the future. Conversely adding 1090ES to the Mode S transponder standards provided such limited bandwidth to support ADS-B that there was legitimate concern that this technology would not work in some of the high density US airspaces (NYC, Atlanta, and Chicago), if all commercial and GA aircraft were so equipped.
>
> Standardization on UAT would have been the ideal solution. Unfortunately this did not happen due to the lack of availability of a common frequency thru-out the world and the reluctance of the international aviation community to support this standard. If the FAA had insisted on UAT as the North American standard, it would have dramatically simplified the whole system at the cost of requiring dual equipage on a relatively small number of airliners used on international routes.
>
> For most GA and commercial aircraft, operating within range of ADS-B ground stations, the current mixed UAT / 1090ES environment works well. The big issue is the lack of reliable ADS-B ground station coverage for low altitude operations in remote areas.
>
> However, even in these environments, the future looks promising. There are now low cost dual frequency ADS-B IN receivers on the market that receive both 1090ES and UAT signals. Within the next year or two, single band ADS-B receivers will probably disappear from the market, due to the low cost of the much superior dual band receivers.
>
> The big question is whether POWERFLARM will evolve to fully support this emerging ADS-B environment by incorporating a dual band ADS-B receiver and/or supporting the ADS-B ground station TIS-B capability, or if it will become irrelevant by the introduction of new low cost ADS-B IN solutions designed for the much larger GA community, incorporating not only dual band receivers, but also more sophisticated collision avoidance algorithms that take into account non-typical GA traffic like gliders, parachutists, and balloons.
>

The problem described not a few posts ago was how misinformed, and just
plain wrong, people had helped delay the introduction of PowerFLARM to a
location where it sounds like it could have been useful/wanted. And
those folks did that by harping on ADS-B,... let me guess influenced by
all that Bernald Smith/Miter/UAT pipe dream crap that too many folks
listened to including yourself. But don't let that stop you, and all the
previous harm done, keep on coming back, keep on telling people there is
something just around the corner...

---

So where is it again you fly? What glider do you own and what ADS-B
avionics have you been flying with? For how long? How long have you been
flying with a transponder? And how much practical experience do you have
flying with FLARM? All questions I've asked of you for before and you
never answer. So let me take a stab at that whole situation and if I get
any of this wrong I apologize and feel free to correct me...

You are a member of the Minnesota Soaring Club, you don't own your own
glider, you don't fly cross country much, you never fly competitions,
and you don't own or fly with a PowerFLARM or ADS-B Out? Is that right?
Just trying to judge your background for all the stuff you post about.
And from a technology viewpoint maybe you could let us know what
experience you have with high-technology, electronics, avionics, or say
actually getting any technology product to market?

You've been on r.a.s many times describing what seems like a dangerous
environment with lots of GA traffic where you fly and why gliders in
that environment apparently urgently need ADS-B equipment. And lots of
us have been baffled about why FLARM never seem appreciated by you since
it seems at times you might also fly with other gliders and/or towplanes
especially if operating from a club/gliderport. I've also asked you
several times where exactly you fly and you never answered. So let me
try there as well, again sorry for any mistakes and feel free to correct
any errors.

I believe you fly with the Minnesota Soaring Club, operating out of
Stanton Airfield. So based on all your past r.a.s posts you seem to
have serious concerns about (mostly GA) mid-air collision risks in that
location. Given those risks I would hope you have convinced the
Minnesota Soaring Club to at least equip their gliders with transponders
so at least ATC can easily see them if they fly within SSR radar
coverage and any PCAS, TCAD and TCAS equipped traffic also have a chance
to detect them as well. That would seem a prudent thing to do for any
glider club operating in what sounds from your past posts to be a high
traffic/high risk-environment. So I have to admit I was a little
surprised when I noticed that you had described to the SSA Executive
Committee back in 2011 that none of the Minnesota Soaring Club Gliders
were transponder equipped. I'm just going by your concerns you have
raised publicly, but in the four years since your comments to the SSA
has the club since corrected this apparent safety problem by installed
transponders and/or ADS-B Out in its glider fleet? Maybe you could give
everybody here an update about your mid-air collision concerns with the
Minnesota Soaring Club?

[email protected]

April 6th 15, 12:20 PM

On 6/04/2015 12:11, Mike Schumann wrote:

> ...The big question is whether POWERFLARM will evolve to fully support
> this emerging ADS-B environment by incorporating a dual band ADS-B
> receiver and/or supporting the ADS-B ground station TIS-B capability,
> or if it will become irrelevant by the introduction of new low cost
> ADS-B IN solutions designed for the much larger GA community,
> incorporating not only dual band receivers, but also more
> sophisticated collision avoidance algorithms that take into account
> non-typical GA traffic like gliders, parachutists, and balloons.
>

I'm surprised you see the future of Flarm as a 'big question' Mike.
Your consistently negative and dismissive attitude to Flarm would make
me think you'd find its future hardly worth a moment's thought.

It seems to me that its mere existence and growing popularity and value
to the soaring community makes it a real burr under your saddle. A sore
you scratch continually, viciously, hopelessly, poignantly.

Let it go, Mike. Move upward and onward with your bright-futured ADS-B
life to the shining Nirvana of universal UAT. Let Flarm wither on the
vine - as in your dreams it surely will. On the other hand, seeing a
grown man bashing his head against a brick wall has had its interesting
moments.

GC

Andy Blackburn[_3_]

April 6th 15, 03:15 PM

On Sunday, April 5, 2015 at 7:11:32 PM UTC-7, Mike Schumann wrote:
>
> I wouldn't ignore ADS-B as the long term solution to the collision avoidance puzzle. It's almost inevitable that this technology will be the cornerstone of collision avoidance for UAVs that are going to start sharing our US airspace.

I've been told that Flarm is working with commercial drone companies. Maybe because the drone manufacturers want something that is light, compact, can run off a battery and won't triple the cost of the drone, in which case those companies making dual-band receivers ought to add a Flarm receiver.

I have not heard of anyone working on, or even contemplating, glider (much less balloon) anti-collision algorithms to their ADS-B solutions. In part I suspect this is because of the possibility that if you don't have all systems using the same algorithm you could generate a situation where a close-proximity anti-collision system makes matters worse rather than better. Has anyone heard of an ADS-B standards body working specifically on developing a single algorithm for collision detection/avoidance (a capability that goes well beyond detecting traffic in an envelope)? Not me. The issue is that the overall philosophy for ADS-B was developed under 5-mile/1000-foot separation assumptions. Anyone who tells you it can be easily adapted to glider scenarios is either misinformed or deliberately misleading you.

Please let us all know when there is an ADS-B-based collision detection and avoidance system available on the market for less than $1000 that has algorithms that have been proven to work for gliders. Speculation about someone maybe in the future thinking about developing something that might kind of work despite the technical challenges with using ADS-B for this purpose - in addition to amounting to spitting into the wind - is irresponsible.

Andy

[email protected]

April 6th 15, 07:36 PM

On Monday, April 6, 2015 at 7:15:21 AM UTC-7, Andy Blackburn wrote:
> I have not heard of anyone working on, or even contemplating, glider (much less balloon) anti-collision algorithms to their ADS-B solutions. In part I suspect this is because of the possibility that if you don't have all systems using the same algorithm you could generate a situation where a close-proximity anti-collision system makes matters worse rather than better. Has anyone heard of an ADS-B standards body working specifically on developing a single algorithm for collision detection/avoidance (a capability that goes well beyond detecting traffic in an envelope)? Not me. The issue is that the overall philosophy for ADS-B was developed under 5-mile/1000-foot separation assumptions. Anyone who tells you it can be easily adapted to glider scenarios is either misinformed or deliberately misleading you.

Sorry, FLARM is not an "anti-collision" system like TCAS, it is a "traffic advisory" system like ADS-B. The only thing that FLARM-specific algorithms do is reduce the number of warnings provided of nearby gliders that are determined not to be on conflicting paths. Having identical firmware in all FLARM units simplifies the programming issues and allows for use of lower-powered processors. Implementing similar algorithms on top of the more diverse ADS-B environment will not have any innate tendency towards making matters worse.

I understand the push for PowerFLARM adoption in the US, and I understand the desire to pushback on misinformed ADS-B speculation. But making crap arguments against crap arguments does not improve this situation. Eventually we will have to come to terms with ADS-B in the US soaring community, whether we like it or not.

Marc

Mike Schumann[_2_]

April 6th 15, 08:15 PM

On Monday, April 6, 2015 at 3:35:11 AM UTC-4, Darryl Ramm wrote:
> On 4/5/15 7:11 PM, Mike Schumann wrote:
> > On Sunday, April 5, 2015 at 4:45:31 AM UTC-4, wrote:
> >> Amazing how big a mess the FAA has made of the ADS-B thing isn't it? It seems like it had the potential to streamline things and provide useful situational awareness about other traffic with a relatively simple and inexpensive device - sort of a like a universal implementation of FLARM-like technology in all aircraft. So much for that.
> >>
> >> My club held off on FLARM for a couple of years as some members thought that ADS-B would make it redundant. We're now installing it to club ships and the tow planes as funds allow and many of the privately owned gliders have it. In my case all it took was one flight to be convinced of the usefulness of FLARM and I was a bit skeptical of its value in our location at first.
> >
> > I wouldn't ignore ADS-B as the long term solution to the collision avoidance puzzle. It's almost inevitable that this technology will be the cornerstone of collision avoidance for UAVs that are going to start sharing our US airspace.
> >
> > The confusion of having two standards (1090ES and UAT) is unfortunate. The FAA (and originally MITRE, which developed the UAT standard) had good intentions. UAT provided the bandwidth needed for the kind of system that would permit a proliferation of other new services far into the future. Conversely adding 1090ES to the Mode S transponder standards provided such limited bandwidth to support ADS-B that there was legitimate concern that this technology would not work in some of the high density US airspaces (NYC, Atlanta, and Chicago), if all commercial and GA aircraft were so equipped.
> >
> > Standardization on UAT would have been the ideal solution. Unfortunately this did not happen due to the lack of availability of a common frequency thru-out the world and the reluctance of the international aviation community to support this standard. If the FAA had insisted on UAT as the North American standard, it would have dramatically simplified the whole system at the cost of requiring dual equipage on a relatively small number of airliners used on international routes.
> >
> > For most GA and commercial aircraft, operating within range of ADS-B ground stations, the current mixed UAT / 1090ES environment works well. The big issue is the lack of reliable ADS-B ground station coverage for low altitude operations in remote areas.
> >
> > However, even in these environments, the future looks promising. There are now low cost dual frequency ADS-B IN receivers on the market that receive both 1090ES and UAT signals. Within the next year or two, single band ADS-B receivers will probably disappear from the market, due to the low cost of the much superior dual band receivers.
> >
> > The big question is whether POWERFLARM will evolve to fully support this emerging ADS-B environment by incorporating a dual band ADS-B receiver and/or supporting the ADS-B ground station TIS-B capability, or if it will become irrelevant by the introduction of new low cost ADS-B IN solutions designed for the much larger GA community, incorporating not only dual band receivers, but also more sophisticated collision avoidance algorithms that take into account non-typical GA traffic like gliders, parachutists, and balloons.
> >
>
> The problem described not a few posts ago was how misinformed, and just
> plain wrong, people had helped delay the introduction of PowerFLARM to a
> location where it sounds like it could have been useful/wanted. And
> those folks did that by harping on ADS-B,... let me guess influenced by
> all that Bernald Smith/Miter/UAT pipe dream crap that too many folks
> listened to including yourself. But don't let that stop you, and all the
> previous harm done, keep on coming back, keep on telling people there is
> something just around the corner...
>
> ---
>
> So where is it again you fly? What glider do you own and what ADS-B
> avionics have you been flying with? For how long? How long have you been
> flying with a transponder? And how much practical experience do you have
> flying with FLARM? All questions I've asked of you for before and you
> never answer. So let me take a stab at that whole situation and if I get
> any of this wrong I apologize and feel free to correct me...
>
> You are a member of the Minnesota Soaring Club, you don't own your own
> glider, you don't fly cross country much, you never fly competitions,
> and you don't own or fly with a PowerFLARM or ADS-B Out? Is that right?
> Just trying to judge your background for all the stuff you post about.
> And from a technology viewpoint maybe you could let us know what
> experience you have with high-technology, electronics, avionics, or say
> actually getting any technology product to market?
>
> You've been on r.a.s many times describing what seems like a dangerous
> environment with lots of GA traffic where you fly and why gliders in
> that environment apparently urgently need ADS-B equipment. And lots of
> us have been baffled about why FLARM never seem appreciated by you since
> it seems at times you might also fly with other gliders and/or towplanes
> especially if operating from a club/gliderport. I've also asked you
> several times where exactly you fly and you never answered. So let me
> try there as well, again sorry for any mistakes and feel free to correct
> any errors.
>
> I believe you fly with the Minnesota Soaring Club, operating out of
> Stanton Airfield. So based on all your past r.a.s posts you seem to
> have serious concerns about (mostly GA) mid-air collision risks in that
> location. Given those risks I would hope you have convinced the
> Minnesota Soaring Club to at least equip their gliders with transponders
> so at least ATC can easily see them if they fly within SSR radar
> coverage and any PCAS, TCAD and TCAS equipped traffic also have a chance
> to detect them as well. That would seem a prudent thing to do for any
> glider club operating in what sounds from your past posts to be a high
> traffic/high risk-environment. So I have to admit I was a little
> surprised when I noticed that you had described to the SSA Executive
> Committee back in 2011 that none of the Minnesota Soaring Club Gliders
> were transponder equipped. I'm just going by your concerns you have
> raised publicly, but in the four years since your comments to the SSA
> has the club since corrected this apparent safety problem by installed
> transponders and/or ADS-B Out in its glider fleet? Maybe you could give
> everybody here an update about your mid-air collision concerns with the
> Minnesota Soaring Club?

You are correct. I am a member of the MN Soaring Club. I don't fly competitions. We operate out of Stanton Airfield, which is just inside the Twin Cities Mode C veil.

None of our club ships and most private gliders at Stanton are neither FLARM, Transponder, nor ADS-B equipped. The reason for that is that most of our pilots are not willing to invest in partial solutions that we think will become obsolete in the next couple of years, as lower cost ADS-B options become available.

As far as my background goes, I was extensively involved with MITRE a number of years ago in their attempt to demonstrate to the FAA the performance capabilities of their low cost UAT ADS-B technology. All the testing was a success. The problem, which continues to this day, is that the FAA has dug in their heels on authorizing low cost consumer grade GPS chip sets for ADS-B OUT applications in VFR GA aircraft. My personal feeling is that eventually the FAA is going to cave on this issue, or they are going to be forced to subsidize a certified chip set that meets their specs. Otherwise, the political pressure from AOPA is going to become unsustainable as 2020 approaches.

As far as FLARM goes, a number of us were quite excited about this technology when it was first introduced in Europe, before the ADS-B bandwagon started rolling here in the US. Unfortunately, FLARM specifically prohibited the use of this technology in the US. One reason was that the European FLARM frequency was unavailable in the US. A bigger reason seemed to be the unwillingness of FLARM to expose themselves to the litigious US product liability environment, which is certainly understandable.

A number of years ago FLARM apparently had a change of heart, resulting in the introduction of the POWERFLARM product. The problem that I, and numerous other glider pilots have with POWERFLARM is the half baked implementation of ADS-B support, which significantly limits its usefulness in identifying non-glider based threats. TIS-B support would have been a huge feature, as this would immediately make all existing transponder equipped aircraft visible.

Unfortunately, the FLARM team did not want to bother with TIS-B. I assume that one reason is that they though this would be a temporary technology, which would become redundant in 2020 when most aircraft will be ADS-B out equipped. Unfortunately, the FLARM team didn't take into account that there are going to be UAT equipped aircraft that will be invisible without the TIS-B function. One work around would be incorporating a dual frequency ADS-B receiver so that POWERFLARM can see both UAT and 1090ES equipped aircraft.. That approach is actually technically better than TIS-B in remote rural areas where aircraft are out of range of ADS-B ground stations.

Blaming me and other pilots who are trying to educate the glider community on what their options are for the disappointing sales of POWERFLARM is ridiculous. The reason a lot of people aren't buying POWERFLARM units is that they perceive this to be a half baked solution for areas near major metropolitan airports, where a significant collision threat is non-glider traffic.

I suspect that if POWERFLARM got their act together and fully supported the FAA's ADS-B architecture, pilots like me would have whole different attitude. With that kind of product the MN Soaring Club might even become a customer.

Darryl Ramm

April 6th 15, 09:33 PM

On 4/6/15 11:36 AM, wrote:
> On Monday, April 6, 2015 at 7:15:21 AM UTC-7, Andy Blackburn wrote:
>> I have not heard of anyone working on, or even contemplating, glider (much less balloon) anti-collision algorithms to their ADS-B solutions. In part I suspect this is because of the possibility that if you don't have all systems using the same algorithm you could generate a situation where a close-proximity anti-collision system makes matters worse rather than better. Has anyone heard of an ADS-B standards body working specifically on developing a single algorithm for collision detection/avoidance (a capability that goes well beyond detecting traffic in an envelope)? Not me. The issue is that the overall philosophy for ADS-B was developed under 5-mile/1000-foot separation assumptions. Anyone who tells you it can be easily adapted to glider scenarios is either misinformed or deliberately misleading you.
>
> Sorry, FLARM is not an "anti-collision" system like TCAS, it is a "traffic advisory" system like ADS-B. The only thing that FLARM-specific algorithms do is reduce the number of warnings provided of nearby gliders that are determined not to be on conflicting paths. Having identical firmware in all FLARM units simplifies the programming issues and allows for use of lower-powered processors. Implementing similar algorithms on top of the more diverse ADS-B environment will not have any innate tendency towards making matters worse.
>
> I understand the push for PowerFLARM adoption in the US, and I understand the desire to pushback on misinformed ADS-B speculation. But making crap arguments against crap arguments does not improve this situation. Eventually we will have to come to terms with ADS-B in the US soaring community, whether we like it or not.
>
> Marc

OK so being careful on semantics is useful, yes the only
*anti-collision* system is TCAS-II, everything else is situations
awareness or traffic warning only. And to look at ADS-B, how/whether
ADS-B plays a role in any anti-collision future needs to be decided.
RTCA and the word's avionics manufactures and regulators don't have
anything close a clear path for use of ADS-B in real collision avoidance
either at the high-end where TCAS II us used today or something more
affordable for say the GA market. And to some extent they don't need to
as TCAS II while not perfect works pretty well and doing much more is an
extremely difficult problem. And hey besides everybody out there who is
a collision threat has a transponder... right?

And that leads to the double damnation with all the past talk about
UAT-Out in gliders. It did not provide TCAS II compatibility for
aircraft equipped with TCAS II, you needed a separate transponder for
that so an issue where you have lots of airliners and fast jets. But
even at a simpler level, forgetting anti-collision stuff, the
low-cost/low-power/compact UAT-Out systems talked about for gliders
can't even do situational awareness or traffic warning. There were
UAT-Out boxes with no receiver, and no display, and no integration with
common soaring displays or software etc. Not anything even as
start/proof of concept. And certainly no smarts for predicting/warning
about threats in a soaring like environment like FLARM has, and no signs
for who would ever do all that development and integration and
production and support work for a very small soaring community (and a
market effectively unique to the USA).

Especially while ADS-B remains prohibitively experience and complex at
least for a certified aircraft I don't the need for most members of the
US soaring community to worry too about it. Folks operating tow planes
in areas where they will need to comply with the 2020 carriage mandate
are the ones I most feel for at the moment, and I hope as that deadline
gets closer the product available will help reduce costs to those
operators and there is useful sharing of information between folks.
Otherwise right now it's mostly just keeping an eye on budgets and
planning for some ADS-B equipage hit for those tow planes prior to 2020.

Otherwise it's the same old same old. If you feel gliders-glider and
glider-towplane collision risks are significant equip with a PowerFLARM,
and get others locally to do the same. If the concern is
GA/Airliner/Military traffic etc. equip with a transponder. If you are
technically inclined and own an experimental glider say with a Trig
TT-21/22 then by all means play with ADS-B Out, be careful how that is
set up (I've helped several owners who want to do that get going with
1090ES Out). And those experiments could help see if ADS-B Out is useful
for things like longer-range air-air and ground trackng of gliders etc.,
SAR last location, etc. There *is* interesting and useful things that
could be looked at there. Anybody want geek help/have questions there
let me know and I'll see if I can help or find you help.

Forgetting *anti-collision*, there is still just nothing close to a
practical ADS-B Out and In (=compact, low power, affordable and
compatible with displays etc.) product(s) today that an owner would
install in a typical glider that would give traffic/collision threat
information to/from nearby ADS-B equipped aircraft. I'd like to see
folks who are still pushing ADS-B crap in the soaring community to have
some, or any, experience flying with what they keep going on about, and
to be able to describe exactly what traffic awareness/traffic warnings
works, how you integrate things, how much it costs, etc.

And we'll have to wait and see what happens with low-power Mode S
beacon/1090ES Out. Maybe technology will come along there. It's a little
too early to be able to guess. But I suspect if anything that type of
technology might end up being used in mid-size UAVs. For the soaring
community's sake I hope those systems end-up being 1090ES (not UAT)-Out
or Dual-link Out. They damn well better have Mode-S transponders, and
companies are already building some impressive Mode-S systems targeting
UAVs (like Sagetech http://www.sagetechcorp.com/unmanned-solutions/).
Hopefully the Mitre/pro-UAT folks don't get to cause a dangerous mess
there, but clearly pushing UAT-Out for UAV use is what Mitre wants to
do. Mid-size and larger UAV certainly worry me. The emergence of UAVs
and their regulation and avionics requirements, and what Mitre exactly
is doing there (they may not be working towards the best interests of
the soaring community at all, I do not see how pushing any UAT-Out
beacon technology does) would be a good area for the SSA to keep watching.

Darryl Ramm

April 6th 15, 10:11 PM

On 4/6/15 12:15 PM, Mike Schumann wrote:
> On Monday, April 6, 2015 at 3:35:11 AM UTC-4, Darryl Ramm wrote:
>> On 4/5/15 7:11 PM, Mike Schumann wrote:
>>> On Sunday, April 5, 2015 at 4:45:31 AM UTC-4, wrote:
>>>> Amazing how big a mess the FAA has made of the ADS-B thing isn't it? It seems like it had the potential to streamline things and provide useful situational awareness about other traffic with a relatively simple and inexpensive device - sort of a like a universal implementation of FLARM-like technology in all aircraft. So much for that.
>>>>
>>>> My club held off on FLARM for a couple of years as some members thought that ADS-B would make it redundant. We're now installing it to club ships and the tow planes as funds allow and many of the privately owned gliders have it. In my case all it took was one flight to be convinced of the usefulness of FLARM and I was a bit skeptical of its value in our location at first.
>>>
>>> I wouldn't ignore ADS-B as the long term solution to the collision avoidance puzzle. It's almost inevitable that this technology will be the cornerstone of collision avoidance for UAVs that are going to start sharing our US airspace.
>>>
>>> The confusion of having two standards (1090ES and UAT) is unfortunate. The FAA (and originally MITRE, which developed the UAT standard) had good intentions. UAT provided the bandwidth needed for the kind of system that would permit a proliferation of other new services far into the future. Conversely adding 1090ES to the Mode S transponder standards provided such limited bandwidth to support ADS-B that there was legitimate concern that this technology would not work in some of the high density US airspaces (NYC, Atlanta, and Chicago), if all commercial and GA aircraft were so equipped.
>>>
>>> Standardization on UAT would have been the ideal solution. Unfortunately this did not happen due to the lack of availability of a common frequency thru-out the world and the reluctance of the international aviation community to support this standard. If the FAA had insisted on UAT as the North American standard, it would have dramatically simplified the whole system at the cost of requiring dual equipage on a relatively small number of airliners used on international routes.
>>>
>>> For most GA and commercial aircraft, operating within range of ADS-B ground stations, the current mixed UAT / 1090ES environment works well. The big issue is the lack of reliable ADS-B ground station coverage for low altitude operations in remote areas.
>>>
>>> However, even in these environments, the future looks promising. There are now low cost dual frequency ADS-B IN receivers on the market that receive both 1090ES and UAT signals. Within the next year or two, single band ADS-B receivers will probably disappear from the market, due to the low cost of the much superior dual band receivers.
>>>
>>> The big question is whether POWERFLARM will evolve to fully support this emerging ADS-B environment by incorporating a dual band ADS-B receiver and/or supporting the ADS-B ground station TIS-B capability, or if it will become irrelevant by the introduction of new low cost ADS-B IN solutions designed for the much larger GA community, incorporating not only dual band receivers, but also more sophisticated collision avoidance algorithms that take into account non-typical GA traffic like gliders, parachutists, and balloons.
>>>
>>
>> The problem described not a few posts ago was how misinformed, and just
>> plain wrong, people had helped delay the introduction of PowerFLARM to a
>> location where it sounds like it could have been useful/wanted. And
>> those folks did that by harping on ADS-B,... let me guess influenced by
>> all that Bernald Smith/Miter/UAT pipe dream crap that too many folks
>> listened to including yourself. But don't let that stop you, and all the
>> previous harm done, keep on coming back, keep on telling people there is
>> something just around the corner...
>>
>> ---
>>
>> So where is it again you fly? What glider do you own and what ADS-B
>> avionics have you been flying with? For how long? How long have you been
>> flying with a transponder? And how much practical experience do you have
>> flying with FLARM? All questions I've asked of you for before and you
>> never answer. So let me take a stab at that whole situation and if I get
>> any of this wrong I apologize and feel free to correct me...
>>
>> You are a member of the Minnesota Soaring Club, you don't own your own
>> glider, you don't fly cross country much, you never fly competitions,
>> and you don't own or fly with a PowerFLARM or ADS-B Out? Is that right?
>> Just trying to judge your background for all the stuff you post about.
>> And from a technology viewpoint maybe you could let us know what
>> experience you have with high-technology, electronics, avionics, or say
>> actually getting any technology product to market?
>>
>> You've been on r.a.s many times describing what seems like a dangerous
>> environment with lots of GA traffic where you fly and why gliders in
>> that environment apparently urgently need ADS-B equipment. And lots of
>> us have been baffled about why FLARM never seem appreciated by you since
>> it seems at times you might also fly with other gliders and/or towplanes
>> especially if operating from a club/gliderport. I've also asked you
>> several times where exactly you fly and you never answered. So let me
>> try there as well, again sorry for any mistakes and feel free to correct
>> any errors.
>>
>> I believe you fly with the Minnesota Soaring Club, operating out of
>> Stanton Airfield. So based on all your past r.a.s posts you seem to
>> have serious concerns about (mostly GA) mid-air collision risks in that
>> location. Given those risks I would hope you have convinced the
>> Minnesota Soaring Club to at least equip their gliders with transponders
>> so at least ATC can easily see them if they fly within SSR radar
>> coverage and any PCAS, TCAD and TCAS equipped traffic also have a chance
>> to detect them as well. That would seem a prudent thing to do for any
>> glider club operating in what sounds from your past posts to be a high
>> traffic/high risk-environment. So I have to admit I was a little
>> surprised when I noticed that you had described to the SSA Executive
>> Committee back in 2011 that none of the Minnesota Soaring Club Gliders
>> were transponder equipped. I'm just going by your concerns you have
>> raised publicly, but in the four years since your comments to the SSA
>> has the club since corrected this apparent safety problem by installed
>> transponders and/or ADS-B Out in its glider fleet? Maybe you could give
>> everybody here an update about your mid-air collision concerns with the
>> Minnesota Soaring Club?
>
> You are correct. I am a member of the MN Soaring Club. I don't fly competitions. We operate out of Stanton Airfield, which is just inside the Twin Cities Mode C veil.
>
> None of our club ships and most private gliders at Stanton are neither FLARM, Transponder, nor ADS-B equipped. The reason for that is that most of our pilots are not willing to invest in partial solutions that we think will become obsolete in the next couple of years, as lower cost ADS-B options become available.
>
> As far as my background goes, I was extensively involved with MITRE a number of years ago in their attempt to demonstrate to the FAA the performance capabilities of their low cost UAT ADS-B technology. All the testing was a success. The problem, which continues to this day, is that the FAA has dug in their heels on authorizing low cost consumer grade GPS chip sets for ADS-B OUT applications in VFR GA aircraft. My personal feeling is that eventually the FAA is going to cave on this issue, or they are going to be forced to subsidize a certified chip set that meets their specs. Otherwise, the political pressure from AOPA is going to become unsustainable as 2020 approaches.
>
> As far as FLARM goes, a number of us were quite excited about this technology when it was first introduced in Europe, before the ADS-B bandwagon started rolling here in the US. Unfortunately, FLARM specifically prohibited the use of this technology in the US. One reason was that the European FLARM frequency was unavailable in the US. A bigger reason seemed to be the unwillingness of FLARM to expose themselves to the litigious US product liability environment, which is certainly understandable.
>
> A number of years ago FLARM apparently had a change of heart, resulting in the introduction of the POWERFLARM product. The problem that I, and numerous other glider pilots have with POWERFLARM is the half baked implementation of ADS-B support, which significantly limits its usefulness in identifying non-glider based threats. TIS-B support would have been a huge feature, as this would immediately make all existing transponder equipped aircraft visible.
>
> Unfortunately, the FLARM team did not want to bother with TIS-B. I assume that one reason is that they though this would be a temporary technology, which would become redundant in 2020 when most aircraft will be ADS-B out equipped. Unfortunately, the FLARM team didn't take into account that there are going to be UAT equipped aircraft that will be invisible without the TIS-B function. One work around would be incorporating a dual frequency ADS-B receiver so that POWERFLARM can see both UAT and 1090ES equipped aircraft. That approach is actually technically better than TIS-B in remote rural areas where aircraft are out of range of ADS-B ground stations.
>
> Blaming me and other pilots who are trying to educate the glider community on what their options are for the disappointing sales of POWERFLARM is ridiculous. The reason a lot of people aren't buying POWERFLARM units is that they perceive this to be a half baked solution for areas near major metropolitan airports, where a significant collision threat is non-glider traffic.
>
> I suspect that if POWERFLARM got their act together and fully supported the FAA's ADS-B architecture, pilots like me would have whole different attitude. With that kind of product the MN Soaring Club might even become a customer.
>

Thanks for the info.

TIS-B won't work without ADS-B Out, as you know. And in certified
aircraft, including any glider used for training you know that is a
multi-$k cost, and eventually TIS-B will go away, whether there are
affordable systems that could be usable in glider before then is an open
question. Meanwhile PCAS provides many PowerFLARM owners with useful
help for purely transponder equipped traffic, but with usual PCAS
limitations. And for compatibly with PCAS/TCAD/TCAS II then you need a
transponder anyhow. So I do not get why any club flying in what you keep
describing as such a high-risk environment would keep putting off
adopting transponders. Seems a bit of liability exposure, maybe one I'd
might have been careful about talking about publicly, but I appreciate
you being willing to publicly share your safety concerns about the
Minnesota Soaring Club operations. Especially since most of us just have
not been able to fathom the apparently unique situation, where other
clubs and owners have been willing/able to adopt PowerFLARM and/or
transponders as a best-available solution for their needs.

So the Minnesota Soaring Club is making what seems like (from your
description) critical safety decisions based on the hope that things
will change and an ADS-B solution will appear? Do they have a timeline
when they expect that to happen? Is there a time for when they will
revisit fitting currently available transponder technology to help
reduce the collision risk in this dangerous high-traffic area? Does the
FAA organizations in the local area and local GA pilots know of the
clubs mid-air collision risk concerns? And that most of the gliders are
not transponder equipped? Any joint-work on how to minimize those risks?

In high traffic areas (including GA) in the CA/NV area the local FAA
folks have been very encouraging/welcoming of adoption of transponders,
and have been really good at working together with the glider community.

George Haeh

April 6th 15, 10:55 PM

Before PowerFlarm, I had two close encounters with airliner turboprops in
Class E airspace. At my old club I took a photo of a close encounter
between an airline turboprop and a towplane pulling a glider below 2000
AGL.

With PowerFlarm, I spot their ADS-B returns 10+ miles away. Very easy to
stay well out of their way.

Air Avionics has a project website ads-b.de with a European outlook (Google
translate recommended if your German is challenged).

A Dutch website discussed using PowerFlarm for GPS input to a transponder,
but non-GPS data has to be filtered out. Can't find that webpage any more,
but filtered PF GPS data looks like a good way to go.

Darryl Ramm

April 6th 15, 11:17 PM

Andy Blackburn[_3_]

April 6th 15, 11:39 PM

On Monday, April 6, 2015 at 11:36:33 AM UTC-7, wrote:
>
> Sorry, FLARM is not an "anti-collision" system like TCAS, it is a "traffic advisory" system like ADS-B. The only thing that FLARM-specific algorithms do is reduce the number of warnings provided of nearby gliders that are determined not to be on conflicting paths. Having identical firmware in all FLARM units simplifies the programming issues and allows for use of lower-powered processors. Implementing similar algorithms on top of the more diverse ADS-B environment will not have any innate tendency towards making matters worse.
>

I'll explain.

After talking to the Flarm engineers, I concluded that you need to have a more nuanced view than "anti-collision" and "traffic advisory". The middle ground is what Flarm does and ADS-B does not. Call it "collision advisory" then. It tells the pilot not only is there an aircraft within some airspace volume around him, but does it have a trajectory (forecasted out some tens of seconds and based on knowledge of what type of aircraft it is) that has a reasonable probability of intersecting his aircraft's trajectory. It then displays quadrant and altitude differential for the pilot to act on (TCAS additionally tells the pilot what to do, that is true, but it doesn't fly the airplane, so the pilot is still in the loop for collision avoidance). Collision advisory like Flarm must account not only for filtering threats from non-threats, but also how pilots are likely to respond to how the threat is presented. Flarm uses a particular convention, but others are possible - all the way up to TCAS-type RAs.

The filtering of collision threat versus non-threats in a glider scenario is the entire difference in suitability between Flarm and ADS-B. Trying to do this kind of filtering without a position forecasting algorithm is challenging because you can't effectively filter threats from non-threats. Without a common position forecasting algorithm across all systems you might have one system give collision advisories based one one set of assumptions and another system issuing advisories on another set of assumptions and could lead to "you zig, I zag" kinds of asymmetric warnings and pilot reactions.

Consistent warning algorithm and advisory display results in better (but not perfect) pilot response to collision advisories. Think about a head-to-head approach. It's hard enough for pilots to deal with Flarm today (turn left? turn right? climb? dive?) but it can get worse if the warnings come at significantly different times (or not at all) and with different philosophies of what to display. Consistent position forecasting and consistent display of the threat are critical to pilots taking successful and non-conflicting action to avoid a collision.

To illustrate - Imagine three different (ADS-B-based) systems on three different gliders in a thermal - one forecasts turning and uses total energy based on received GPS position and trends (this is not as effective or reliable as doing what Flarm does by forecasting future position prior to transmission, but leave that aside for now), another algorithm does a straight extrapolation of the current instantaneous velocity vector and a third is position only. Imagine the first system also gives you an indication of where the threat will be relative to you when it is expected to be at closest approach so you can steer away from that point and the second just tells you when either gilder is pointed at the other and indicates where to look to pick it up. The third one will give you advisories continuously as long as any other glider is within a thousand feet of you or so (my LX 9000 does this, but only once when it picks up a new target. Even so, I want to turn it off most of the time). In a crowded thermal these three different approaches to collision threat filtering and display could - with pilots in the loop and reacting - create all kinds of chaos that I would think of as making matters worse.

That's why I conclude not having a single collision advisory algorithm and display philosophy could make matters worse. I wonder if this is why ADS-B systems are pretty conservative about what they tell the pilots about traffic vs collision threats.

Andy

Darryl Ramm

April 6th 15, 11:41 PM

On Monday, April 6, 2015 at 3:00:05 PM UTC-7, George Haeh wrote:
> Before PowerFlarm, I had two close encounters with airliner turboprops in
> Class E airspace. At my old club I took a photo of a close encounter
> between an airline turboprop and a towplane pulling a glider below 2000
> AGL.
>
> With PowerFlarm, I spot their ADS-B returns 10+ miles away. Very easy to
> stay well out of their way.
>
> Air Avionics has a project website ads-b.de with a European outlook (Google
> translate recommended if your German is challenged).
>
> A Dutch website discussed using PowerFlarm for GPS input to a transponder,
> but non-GPS data has to be filtered out. Can't find that webpage any more,
> but filtered PF GPS data looks like a good way to go.

In pre-PCAS flying days I had an eye-opener: I was a few thousand feet AGL about 5 miles south of the Panoche VOR in California. I was working a weak thermal in my DG-303, lots of small scraggly excuses for cumulus in the area. I take a turn and as I'm coming around a Cessna 152 cuts right through my thermal circle just above me. *Wholly Crap* I pushed the nose down, they fly on off into the distance not flintching at all, I don't expect they ever saw me. They had 2 POB, I suspect a student under a hood flying a radial the Panoche VOR. I was trying to look out and all I can think is that Cessna was sitting against the background of those scraggly clouds and just very hard to see.

I ordered a Zaon PCAS after that and got one of the first ones available, an old grey unit. That easily earned it's keep.

Multiple times, especially when retuning the local busy GA airport the PCAS would give useful warnings of GA aircraft. And we sometimes had issue in the area with poor quality radio calls/position reports, sometime just due to inexperienced student pilots using that airport as an early cross country destination.

On another occasion my PCAS was going nuts and I kept looking around and could not see anybody and it just stayed a constant range (close) and warning 1,000 foot or so above and then started to get lower. Kind of a useful indication that even when you are looking you can't necessarily see them (and to trust the PCAS that something is out there). Then I spot this crazy aircraft a Thrush or similar equipped for something interesting, covered in antennas. That was orbiting right above me and slowly descending to look at me.. Maybe he was just curious, kind of annoyed me, and to this day I wonder what the aircraft was rigged up for.

kirk.stant

April 7th 15, 12:19 AM

OK, here is my PCAS story, then a comment for Mike:

Couple of weeks ago, flying down to Ardmore OK to pick up our new towplane, I'm riding right seat in a nice RV-6. VFR on top, squawking 1200, pilot is messing around with a radio, and I'm playing with my trusty PCAS (I NEVER fly without it). Odd, it shows our 1200 code, but shows us at FL024 (we were at about 9600ft). Tried this several times, same result. Then I lood across cockpit and at 10 I see a BIG CLOSE AIRPLANE!!, about a mile away on a collision course. I could see the top of the cabin so we were probably 100 above it, but it sure looked impressive! I yelled "AIRPLANE - PULL UP!" and we bumped up a hundred feet or so as it passed underneath us, apparently unconcerned.

Now, what we figured happened is: 1. Our transponder was stuck putting out a bad altitude (2400ft) instead of the actual pressure alt (about 9400ft). 2. My PCAS was telling me that - but I didn't connect the dots. And 3. since we were putting out our altitude as 2400 ft, the airliners (I think it was an Airbus 319) didn't get a TCAS warning, and we didn't get a PCAS warning (since it thought we we low and the airliner high above the threat bubble!)

Would have made an interesting NTSB report if we had entered that Airbus's cockpit via the windshield.

We cycled the transponder several times and it started to show the correct altitude, which is when the lightbulb came on....

So - PCAS is a wonderful thing. PowerFLARM (which has PCAS + 1090ES ADS-B in + flarm) is even better. But you still have to look out the window!

Oh, and Mike? Your club sounds like mine - bunch of ignorant cheap *******s flying beat-up old gliders, and who think a Macready ring on a Winter vario is a trick flight computer. Out of the 20 some club and private gliders on our field, 2 have PF, 2 have transponders, and the rest barely have audio varios. I really think it's a cultural thing (glassholes & racers vs the rest). But your argument against PF and for ADS-B is bogus, since YOU STILL HAVE TO HAVE A MODE A/C OR S TRANSPONDER WITH YOUR MAGIC UAT ADS-B OUT BOX! Will you please explain to me how you can get away with a UAT-only solution in a glider? And how will it help you see everyone else out there?

Kirk
66
Zaon MRX PCAS and PowerFLARM brick.

Andy Blackburn[_3_]

April 7th 15, 01:26 AM

On Monday, April 6, 2015 at 12:15:02 PM UTC-7, Mike Schumann wrote:
>
> Blaming me and other pilots who are trying to educate the glider community on what their options are for the disappointing sales of POWERFLARM is ridiculous. The reason a lot of people aren't buying POWERFLARM units is that they perceive this to be a half baked solution for areas near major metropolitan airports, where a significant collision threat is non-glider traffic.
>
> I suspect that if POWERFLARM got their act together and fully supported the FAA's ADS-B architecture, pilots like me would have whole different attitude. With that kind of product the MN Soaring Club might even become a customer.

Flarm is installed in something like 75% of the active glider fleet worldwide as of a couple of years ago so I'd be hard-pressed to call it a disappointment. It got most of that without any ADS-B In capability. The US adoption has been slower, but there are a number of reasons that probably don't auger well for those gliders going being equipped with ADS-B either - such as relatively large fleet of older gliders without electrics, a different philosophy for non-privately owned gliders (rides and training) and a number that are in more remote locations with no urgent perceived need for much of anything.

I think it misreads the situation in the US to conclude that people are holding off buying PowerFLARM because they are chomping at the bit to put $5-6000 worth of ADS-B kit into their $6-7000 glider.

Would it be better if Flarm had implemented dual-mode UAT and 1090ES In? Possibly at the margin, but the cost of PF versus the original Flarm is already much higher and that variant would only be useful in the brain-dead US ADS-B environment.

Before doing anything I'd recommend the Flarm guys take a hard look at how much UAT gets adopted versus 1090 ES in the US. There is a decent probability that UAT Out will have lower than predicted adoption as the benefits of Mode S + 1090ES Out become more apparent in terms of cost, simplicity and installation. Most non-gliders Carrying ADS-B In will be carrying 1090ES or dual mode In anyway so putting a (hopefully) cheap GPS on a Mode S transponder will get you seen by traffic. Given the relative speed differences it will be a lot easier for them to avoid you than for you to get out of their way anyway.

Andy

[email protected]

April 7th 15, 02:37 AM

On Monday, April 6, 2015 at 3:39:17 PM UTC-7, Andy Blackburn wrote:
> The filtering of collision threat versus non-threats in a glider scenario is the entire difference in suitability between Flarm and ADS-B. Trying to do this kind of filtering without a position forecasting algorithm is challenging because you can't effectively filter threats from non-threats. Without a common position forecasting algorithm across all systems you might have one system give collision advisories based one one set of assumptions and another system issuing advisories on another set of assumptions and could lead to "you zig, I zag" kinds of asymmetric warnings and pilot reactions.

I'll explain my (over-simplified and and I'm open to accept wrong) view. Flarm and ADS-B start out with the same source data, a position and velocity vector obtained from GPS. The primary difference is that Flarm calculates a forecasted trajectory (I've never looked at the details, but I wouldn't be surprised if it's more of a probable trajectory sphere at some time t+x) from the raw data, ADS-B simply transmits the raw position and velocity vector. The great advantage of the Flarm approach is that all it need do is intersect all of the received trajectories (or spheres) with the calculated trajectory for your own glider, which is great if you need to do it on an 8 bit processor. A lot more computation is required to accomplish the same thing with received ADS-B data, as the trajectory calculations need to be performed for all received targets likely to be a threat. That is not impossible, it just takes a lot more computational power in your glider, but we live in the age of low power consumption 64 bit processors that cost a USD or two in reasonable quantities.

The fact that all Flarm devices calculate threats in the same way is helpful, but in the end, it has no control over what any of the pilots involved do to avoid a collision, whereas with TCAS-II, the pilots most certainly should do exactly what their device calls for. I don't know if Flarm transmits data more frequently than the once per second slots I believe are allocated for ADS-B, perhaps someone else knows. Beyond that, however, I see nothing preventing anyone from taking the received data, filtering out the more distant targets, and applying target type (including glider) specific trajectory calculations to more intelligently provide traffic advisories. If someone has facts that suggest otherwise, I'm interested in hearing them.

I think the important thing to keep in mind is that gliders probably won't be exempt from the ADS-B (or transponder) mandate in the US forever. Boeing, Amazon, Google, and the rest of the US drone industry will eventually figure out (if they haven't already) that the easy solution for their problems is to lobby hard for all aircraft in US airspace to be ADS-B out equipped.. We don't have that kind of clout, nor does AOPA or EAA.

Marc

Mike Schumann[_2_]

April 7th 15, 05:17 AM

On Monday, April 6, 2015 at 5:12:01 PM UTC-4, Darryl Ramm wrote:
> On 4/6/15 12:15 PM, Mike Schumann wrote:
> > On Monday, April 6, 2015 at 3:35:11 AM UTC-4, Darryl Ramm wrote:
> >> On 4/5/15 7:11 PM, Mike Schumann wrote:
> >>> On Sunday, April 5, 2015 at 4:45:31 AM UTC-4, wrote:
> >>>> Amazing how big a mess the FAA has made of the ADS-B thing isn't it? It seems like it had the potential to streamline things and provide useful situational awareness about other traffic with a relatively simple and inexpensive device - sort of a like a universal implementation of FLARM-like technology in all aircraft. So much for that.
> >>>>
> >>>> My club held off on FLARM for a couple of years as some members thought that ADS-B would make it redundant. We're now installing it to club ships and the tow planes as funds allow and many of the privately owned gliders have it. In my case all it took was one flight to be convinced of the usefulness of FLARM and I was a bit skeptical of its value in our location at first.
> >>>
> >>> I wouldn't ignore ADS-B as the long term solution to the collision avoidance puzzle. It's almost inevitable that this technology will be the cornerstone of collision avoidance for UAVs that are going to start sharing our US airspace.
> >>>
> >>> The confusion of having two standards (1090ES and UAT) is unfortunate.. The FAA (and originally MITRE, which developed the UAT standard) had good intentions. UAT provided the bandwidth needed for the kind of system that would permit a proliferation of other new services far into the future. Conversely adding 1090ES to the Mode S transponder standards provided such limited bandwidth to support ADS-B that there was legitimate concern that this technology would not work in some of the high density US airspaces (NYC, Atlanta, and Chicago), if all commercial and GA aircraft were so equipped..
> >>>
> >>> Standardization on UAT would have been the ideal solution. Unfortunately this did not happen due to the lack of availability of a common frequency thru-out the world and the reluctance of the international aviation community to support this standard. If the FAA had insisted on UAT as the North American standard, it would have dramatically simplified the whole system at the cost of requiring dual equipage on a relatively small number of airliners used on international routes.
> >>>
> >>> For most GA and commercial aircraft, operating within range of ADS-B ground stations, the current mixed UAT / 1090ES environment works well. The big issue is the lack of reliable ADS-B ground station coverage for low altitude operations in remote areas.
> >>>
> >>> However, even in these environments, the future looks promising. There are now low cost dual frequency ADS-B IN receivers on the market that receive both 1090ES and UAT signals. Within the next year or two, single band ADS-B receivers will probably disappear from the market, due to the low cost of the much superior dual band receivers.
> >>>
> >>> The big question is whether POWERFLARM will evolve to fully support this emerging ADS-B environment by incorporating a dual band ADS-B receiver and/or supporting the ADS-B ground station TIS-B capability, or if it will become irrelevant by the introduction of new low cost ADS-B IN solutions designed for the much larger GA community, incorporating not only dual band receivers, but also more sophisticated collision avoidance algorithms that take into account non-typical GA traffic like gliders, parachutists, and balloons.
> >>>
> >>
> >> The problem described not a few posts ago was how misinformed, and just
> >> plain wrong, people had helped delay the introduction of PowerFLARM to a
> >> location where it sounds like it could have been useful/wanted. And
> >> those folks did that by harping on ADS-B,... let me guess influenced by
> >> all that Bernald Smith/Miter/UAT pipe dream crap that too many folks
> >> listened to including yourself. But don't let that stop you, and all the
> >> previous harm done, keep on coming back, keep on telling people there is
> >> something just around the corner...
> >>
> >> ---
> >>
> >> So where is it again you fly? What glider do you own and what ADS-B
> >> avionics have you been flying with? For how long? How long have you been
> >> flying with a transponder? And how much practical experience do you have
> >> flying with FLARM? All questions I've asked of you for before and you
> >> never answer. So let me take a stab at that whole situation and if I get
> >> any of this wrong I apologize and feel free to correct me...
> >>
> >> You are a member of the Minnesota Soaring Club, you don't own your own
> >> glider, you don't fly cross country much, you never fly competitions,
> >> and you don't own or fly with a PowerFLARM or ADS-B Out? Is that right?
> >> Just trying to judge your background for all the stuff you post about.
> >> And from a technology viewpoint maybe you could let us know what
> >> experience you have with high-technology, electronics, avionics, or say
> >> actually getting any technology product to market?
> >>
> >> You've been on r.a.s many times describing what seems like a dangerous
> >> environment with lots of GA traffic where you fly and why gliders in
> >> that environment apparently urgently need ADS-B equipment. And lots of
> >> us have been baffled about why FLARM never seem appreciated by you since
> >> it seems at times you might also fly with other gliders and/or towplanes
> >> especially if operating from a club/gliderport. I've also asked you
> >> several times where exactly you fly and you never answered. So let me
> >> try there as well, again sorry for any mistakes and feel free to correct
> >> any errors.
> >>
> >> I believe you fly with the Minnesota Soaring Club, operating out of
> >> Stanton Airfield. So based on all your past r.a.s posts you seem to
> >> have serious concerns about (mostly GA) mid-air collision risks in that
> >> location. Given those risks I would hope you have convinced the
> >> Minnesota Soaring Club to at least equip their gliders with transponders
> >> so at least ATC can easily see them if they fly within SSR radar
> >> coverage and any PCAS, TCAD and TCAS equipped traffic also have a chance
> >> to detect them as well. That would seem a prudent thing to do for any
> >> glider club operating in what sounds from your past posts to be a high
> >> traffic/high risk-environment. So I have to admit I was a little
> >> surprised when I noticed that you had described to the SSA Executive
> >> Committee back in 2011 that none of the Minnesota Soaring Club Gliders
> >> were transponder equipped. I'm just going by your concerns you have
> >> raised publicly, but in the four years since your comments to the SSA
> >> has the club since corrected this apparent safety problem by installed
> >> transponders and/or ADS-B Out in its glider fleet? Maybe you could give
> >> everybody here an update about your mid-air collision concerns with the
> >> Minnesota Soaring Club?
> >
> > You are correct. I am a member of the MN Soaring Club. I don't fly competitions. We operate out of Stanton Airfield, which is just inside the Twin Cities Mode C veil.
> >
> > None of our club ships and most private gliders at Stanton are neither FLARM, Transponder, nor ADS-B equipped. The reason for that is that most of our pilots are not willing to invest in partial solutions that we think will become obsolete in the next couple of years, as lower cost ADS-B options become available.
> >
> > As far as my background goes, I was extensively involved with MITRE a number of years ago in their attempt to demonstrate to the FAA the performance capabilities of their low cost UAT ADS-B technology. All the testing was a success. The problem, which continues to this day, is that the FAA has dug in their heels on authorizing low cost consumer grade GPS chip sets for ADS-B OUT applications in VFR GA aircraft. My personal feeling is that eventually the FAA is going to cave on this issue, or they are going to be forced to subsidize a certified chip set that meets their specs. Otherwise, the political pressure from AOPA is going to become unsustainable as 2020 approaches.
> >
> > As far as FLARM goes, a number of us were quite excited about this technology when it was first introduced in Europe, before the ADS-B bandwagon started rolling here in the US. Unfortunately, FLARM specifically prohibited the use of this technology in the US. One reason was that the European FLARM frequency was unavailable in the US. A bigger reason seemed to be the unwillingness of FLARM to expose themselves to the litigious US product liability environment, which is certainly understandable.
> >
> > A number of years ago FLARM apparently had a change of heart, resulting in the introduction of the POWERFLARM product. The problem that I, and numerous other glider pilots have with POWERFLARM is the half baked implementation of ADS-B support, which significantly limits its usefulness in identifying non-glider based threats. TIS-B support would have been a huge feature, as this would immediately make all existing transponder equipped aircraft visible.
> >
> > Unfortunately, the FLARM team did not want to bother with TIS-B. I assume that one reason is that they though this would be a temporary technology, which would become redundant in 2020 when most aircraft will be ADS-B out equipped. Unfortunately, the FLARM team didn't take into account that there are going to be UAT equipped aircraft that will be invisible without the TIS-B function. One work around would be incorporating a dual frequency ADS-B receiver so that POWERFLARM can see both UAT and 1090ES equipped aircraft. That approach is actually technically better than TIS-B in remote rural areas where aircraft are out of range of ADS-B ground stations.
> >
> > Blaming me and other pilots who are trying to educate the glider community on what their options are for the disappointing sales of POWERFLARM is ridiculous. The reason a lot of people aren't buying POWERFLARM units is that they perceive this to be a half baked solution for areas near major metropolitan airports, where a significant collision threat is non-glider traffic.
> >
> > I suspect that if POWERFLARM got their act together and fully supported the FAA's ADS-B architecture, pilots like me would have whole different attitude. With that kind of product the MN Soaring Club might even become a customer.
> >
>
> Thanks for the info.
>
> TIS-B won't work without ADS-B Out, as you know. And in certified
> aircraft, including any glider used for training you know that is a
> multi-$k cost, and eventually TIS-B will go away, whether there are
> affordable systems that could be usable in glider before then is an open
> question. Meanwhile PCAS provides many PowerFLARM owners with useful
> help for purely transponder equipped traffic, but with usual PCAS
> limitations. And for compatibly with PCAS/TCAD/TCAS II then you need a
> transponder anyhow. So I do not get why any club flying in what you keep
> describing as such a high-risk environment would keep putting off
> adopting transponders. Seems a bit of liability exposure, maybe one I'd
> might have been careful about talking about publicly, but I appreciate
> you being willing to publicly share your safety concerns about the
> Minnesota Soaring Club operations. Especially since most of us just have
> not been able to fathom the apparently unique situation, where other
> clubs and owners have been willing/able to adopt PowerFLARM and/or
> transponders as a best-available solution for their needs.
>
> So the Minnesota Soaring Club is making what seems like (from your
> description) critical safety decisions based on the hope that things
> will change and an ADS-B solution will appear? Do they have a timeline
> when they expect that to happen? Is there a time for when they will
> revisit fitting currently available transponder technology to help
> reduce the collision risk in this dangerous high-traffic area? Does the
> FAA organizations in the local area and local GA pilots know of the
> clubs mid-air collision risk concerns? And that most of the gliders are
> not transponder equipped? Any joint-work on how to minimize those risks?
>
> In high traffic areas (including GA) in the CA/NV area the local FAA
> folks have been very encouraging/welcoming of adoption of transponders,
> and have been really good at working together with the glider community.

Equipping a glider with a transponder will help protect you from airliners that are TCAS equipped. It won't help protect you from your average Cessna that is flying around recreationally, which in our environment is the most significant threat (as well as other gliders). Having a transponder doesn't help your personal situational awareness.

There are a number of very affordable ADS-B IN systems out there that give you great situational awareness today, IF you are ADS-B OUT equipped and within range of an ADS-B ground station. Granted, it won't come close to the functionality that FLARM provides in providing traffic advisories for gliders that are sharing thermals. That's important for competition pilots. Most recreational glider pilots are primarily interested in getting an overview of what A/C are in the area. If I get into an area where there are numerous A/C which I can keep track of visually, I find myself another thermal and stay out of everyone's way.

The reality is that ADS-B is the long term future foundation of the US airspace system. Claiming that it is "crap" is absurd. As glider pilots, we should be working on systems that are tuned to the specific needs of the glider community, but also fit into the overall ADS-B architecture. UAT is, for better or worse, part of this environment, and in the long run any solution worth buying needs to be able to handle this type of traffic.

The BIG problem right now is the cost of ADS-B OUT solutions. Technically, there is no reason that these systems can be as economical as currently available ADS-B IN systems. The entire price premium is a result of the FAA's absurd gold plated specs and certification requirements that are totally inappropriate for VFR aircraft (both gliders and piston powered A/C).

ADS-B OUT solutions for GA applications have finally started shipping, and prices are starting to come down significantly. Glider pilots, like their GA counterparts are to a large degree holding out, waiting for prices to come down. How long people wait to equip is going to be a function of price and capability.

My gut instinct is that we are going to see another slug of very interesting ADS-B products introduced at Oshkosh this year. I wouldn't be surprised to see Trig introduce a new version of their popular transponders with integrated GPS sources for a turnkey ADS-B OUT solution. As prices come down, more people will bite the bullet and make the investment.

The big question for the glider community is whether people will buy a POWERFLARM product that incorporates a half baked ADS-B implementation, of if they will just buy a low cost ADS-B IN receiver and couple it to an iPhone or iPAD running a navigation app. If the POWERFLARM community would quit bashing ADS-B and instead upgrade the product to handle both UAT and 1090ES traffic, there are a lot of people (me included) who might be interested in making the investment.

Andy Blackburn[_3_]

April 7th 15, 05:44 AM

On Monday, April 6, 2015 at 6:37:14 PM UTC-7, wrote:
> On Monday, April 6, 2015 at 3:39:17 PM UTC-7, Andy Blackburn wrote:
> > The filtering of collision threat versus non-threats in a glider scenario is the entire difference in suitability between Flarm and ADS-B. Trying to do this kind of filtering without a position forecasting algorithm is challenging because you can't effectively filter threats from non-threats. Without a common position forecasting algorithm across all systems you might have one system give collision advisories based one one set of assumptions and another system issuing advisories on another set of assumptions and could lead to "you zig, I zag" kinds of asymmetric warnings and pilot reactions.
>
> I'll explain my (over-simplified and and I'm open to accept wrong) view. Flarm and ADS-B start out with the same source data, a position and velocity vector obtained from GPS. The primary difference is that Flarm calculates a forecasted trajectory (I've never looked at the details, but I wouldn't be surprised if it's more of a probable trajectory sphere at some time t+x) from the raw data, ADS-B simply transmits the raw position and velocity vector. The great advantage of the Flarm approach is that all it need do is intersect all of the received trajectories (or spheres) with the calculated trajectory for your own glider, which is great if you need to do it on an 8 bit processor. A lot more computation is required to accomplish the same thing with received ADS-B data, as the trajectory calculations need to be performed for all received targets likely to be a threat. That is not impossible, it just takes a lot more computational power in your glider, but we live in the age of low power consumption 64 bit processors that cost a USD or two in reasonable quantities.
>
> The fact that all Flarm devices calculate threats in the same way is helpful, but in the end, it has no control over what any of the pilots involved do to avoid a collision, whereas with TCAS-II, the pilots most certainly should do exactly what their device calls for. I don't know if Flarm transmits data more frequently than the once per second slots I believe are allocated for ADS-B, perhaps someone else knows. Beyond that, however, I see nothing preventing anyone from taking the received data, filtering out the more distant targets, and applying target type (including glider) specific trajectory calculations to more intelligently provide traffic advisories. If someone has facts that suggest otherwise, I'm interested in hearing them.
>
> I think the important thing to keep in mind is that gliders probably won't be exempt from the ADS-B (or transponder) mandate in the US forever. Boeing, Amazon, Google, and the rest of the US drone industry will eventually figure out (if they haven't already) that the easy solution for their problems is to lobby hard for all aircraft in US airspace to be ADS-B out equipped. We don't have that kind of clout, nor does AOPA or EAA.
>
> Marc

Yes.

There are a couple of additional consideration on prediction pre- versus post- transmission. First, which is which is more robust in the event of lost packets, which happens pretty regularly with RF transmissions. Second, while both Flarm and ADS-B transmit at once per second, the inherent lag associated with post- versus pre- processing apparently works in the favor of Flarm in highly dynamic situations like thermalling. Add to that the lag associated with whether the traffic is ADS-B direct or ADS-R which increases the uncertainty of any predicted probabilistic position bubble and you can start to see why using ADS-B for common glider scenarios could easily devolve into a cloud of false alarms which, if the lags get close to the human reaction time of ~300 milliseconds (plus whatever dynamic response time constants of the gliders are), could melt down the prediction-reaction dynamic loop entirely.

I know less about the politics of it - whatever goes on drones will need to be cheap, cheap, cheap, and possibly lower power and range to keep the aggregate bandwidth requirements down (especially if Amazon gets their way). Flarm may have a leg up on ADS-B on both counts, but the FAA would need to agree and counting on the FAA to do sensible things would.

Andy

kirk.stant

April 7th 15, 04:11 PM

On Monday, April 6, 2015 at 11:17:14 PM UTC-5, Mike Schumann wrote:

> Equipping a glider with a transponder will help protect you from airliners that are TCAS equipped. It won't help protect you from your average Cessna that is flying around recreationally, which in our environment is the most significant threat (as well as other gliders). Having a transponder doesn't help your personal situational awareness.
>

PowerFLARM, on the other hand, DOES (right now, today, in my glider) help protect me from not only other Flarm-equipped gliders, but also from airliners (by showing their 1090ES position) and from those "average Cessna"s carrying a Mode A/C/S transponder. These all show up on my PF display, on my Oudie map, and on my SN10. And since certified airplanes will need BOTH an functioning transponder and some form of ADS-B Out, the chance of someone out there with ONLY a UAT ADS-B Out system is remote.

> There are a number of very affordable ADS-B IN systems out there that give you great situational awareness today, IF you are ADS-B OUT equipped and within range of an ADS-B ground station. Granted, it won't come close to the functionality that FLARM provides in providing traffic advisories for gliders that are sharing thermals. That's important for competition pilots. Most recreational glider pilots are primarily interested in getting an overview of what A/C are in the area. If I get into an area where there are numerous A/C which I can keep track of visually, I find myself another thermal and stay out of everyone's way.

So please describe for me a specific setup of hardware that you can put in your glider, today, to do what you describe above. In your certified training glider. Sure, ADS-B IN is cheap; but without the OUT you are getting what you paid for! Old weather and maybe, some partial traffic. Now, how are you going to get the OUT into your glider? And where are you going to display all the magic traffic info you might get (if you are close enough to a ground station, etc..). In my experimental glider, I can try a Trig/PF lashup, but why bother? A Mode S transponder and a PowerFLARM gives me everything I need, NOW.

> The reality is that ADS-B is the long term future foundation of the US airspace system. Claiming that it is "crap" is absurd. As glider pilots, we should be working on systems that are tuned to the specific needs of the glider community, but also fit into the overall ADS-B architecture. UAT is, for better or worse, part of this environment, and in the long run any solution worth buying needs to be able to handle this type of traffic.
>

ADS-B, yes, but the UAT part is the "crap", as currently implemented. If the FAA and Mitre (or whoever) had come up with a $500 portable UAT IN/OUT with a display, that you could stick on your panel like a PF portable and start seeing all traffic around you (mode A/C/S/ES/UAT) - that would be great.. But that, obviously, didn't happen!

> The BIG problem right now is the cost of ADS-B OUT solutions. Technically, there is no reason that these systems can be as economical as currently available ADS-B IN systems. The entire price premium is a result of the FAA's absurd gold plated specs and certification requirements that are totally inappropriate for VFR aircraft (both gliders and piston powered A/C).
>

Totally agree.

> ADS-B OUT solutions for GA applications have finally started shipping, and prices are starting to come down significantly. Glider pilots, like their GA counterparts are to a large degree holding out, waiting for prices to come down. How long people wait to equip is going to be a function of price and capability.
>

Yes, for example, the Navworx PADS-B looks interesting - but again, only for Experimental aircraft. The cost of any ADS-B Out setup in a certified glider is still going to be high.

> My gut instinct is that we are going to see another slug of very interesting ADS-B products introduced at Oshkosh this year. I wouldn't be surprised to see Trig introduce a new version of their popular transponders with integrated GPS sources for a turnkey ADS-B OUT solution. As prices come down, more people will bite the bullet and make the investment.
>
Are these the same people who don't have transponders now? I hope so, because then I'll see them on my PF!

> The big question for the glider community is whether people will buy a POWERFLARM product that incorporates a half baked ADS-B implementation, of if they will just buy a low cost ADS-B IN receiver and couple it to an iPhone or iPAD running a navigation app. If the POWERFLARM community would quit bashing ADS-B and instead upgrade the product to handle both UAT and 1090ES traffic, there are a lot of people (me included) who might be interested in making the investment.

Back at you: if the ADS-B Community would quit bashing PowerFLARM (which exists and works) and encouraging people to wait for some future ADS-B magicware, perhaps more gliders would be enjoying the protection that PF provides TODAY, while waiting to see what the future actually brings.

Kirk
66

[email protected]

April 7th 15, 05:43 PM

On Wednesday, March 25, 2015 at 6:15:44 PM UTC-4, Andrew Ainslie wrote:
> Has anyone been following the latest moves from the FAA on ads-b and experimental aircraft? A recent article in flying suggested that they are going to relax the requirements for experimental planes so they need a GPS source that is equivalent in performance to TSO'd units.
>
> If this is true, it might relax the requirements for those with Trig TT22 transponders so that they can use cheaper GPS sources like the GRT GPS-EXT-RAIM unit that they sell for just under $500.
>
> I've decided that it's cheap enough to give a try, so I just ordered one and will be playing with it over the next few months. It certainly beats forking out $3000 on the TSO'd unit sold by Trig.
>
> If anyone has opinions, experience or also intends playing with this I'd love to hear. I fly out of Harris hill which is right by a big iron airfield and it'd be nice to see them on a screen before bumping into them. I also like the idea of a couple of us flying with ads-b out so that people around us get to see the in portion. S emus like even a relatively small percentage of us on the new standard could help safety given the idiot decision by the FAA to restrict access to the "in" data to a hockey puck around each plane with "out".

Andrew, although many people want ADS-B to be used for collision avoidance, it's important to understand that ADS-B's original purpose was to improve the quality of the surveillance data that ATC receives. If you stick with that mindset, the complications that followed are much easier to understand..

(BTW - The following are very informative about ADS-B:http://adsbuniversity..com/ads-b-university)

For example:

Problem: Detecting an aircraft's location through the use of radar provides a certain level of accuracy, adding transponder data helps, but what would be best is for the aircraft to report its onboard GPS position to ATC. Solution: Create ADS-B, define the requirements for ADS-B OUT, and require certification so you are sure you know how it works.

Problem: If you are going to use ADS-B information for air traffic control, you want to have some assurance that the GPS data being reported is accurate. Solution: Define the accuracy of the GPS receiver that is necessary and certify it.

Problem: In some places there is a lot of traffic and the transponder based (1090) ADS-B systems might over-crowd the frequency either today or in the future. Solution: Pick another frequency (UAT) that has plenty of capacity and define ADS-B for it.

Problem: The rest of the world isn't concerned about frequency congestion and airlines are less than enthusiastic about having to have both mod existing 1090 transponders and ALSO install a UAT ADS-B box onboard. Solution: Keep 1090 for aircraft that fly above 18,000 since they are the ones that will encounter the overseas environment.

Problem: With two frequencies, the 1090 and UAT don't talk to each other. Not really a problem since the ADS-B ground stations can receive both frequencies and ship it over to the controller. But, okay if it's really necessary, a solution is: When the aircraft are in range of a ground station, re-transmit the data on both frequencies. And keep transponders on *all* aircraft so TCAS can function when there's no ground station available.

You've noticed, I'm sure, that none of these problems/solutions have anything to do with collision avoidance, except in controlled airspace where ATC can see the traffic and issue traffic warnings or vectors. Just like they do today. And new FAA procedures depend on getting the more accurate ADS-B out data. This explains why ADS-B out is further along than ADS-B in, which provides services for pilots, not ATC.

All of this stuff about pilot services like traffic awareness or weather is secondary to the purpose of ADS-B - to improve surveillance data for controllers and FAA. And the concern about frequency congestion still exists, so most of the ADS-B out data will be transmitted on the less congested UAT frequency. That may be crap to many people but it does explain the push for UAT ADS-B systems. The lower cost and power consumption are bonuses but not the main reason.

It's not that FAA isn't interested in improving or developing ADS-B (they are) but that isn't their main focus -improving the quality of the surveillance data they receive. With that perspective, you can see that systems like FLARM, which are intended to help pilots avoid each other without the need for a controller are fundamentally different than what ADS-B was originally designed for. Maybe someday ADS-B will do this, but not today and not in the near future.

Hope that helps sort it out a bit. You have to view it from the main beneficiary's perspective to make the present situation understandable.

Andy Blackburn[_3_]

April 7th 15, 06:00 PM

On Tuesday, April 7, 2015 at 9:43:26 AM UTC-7, wrote:
>
> Problem: The rest of the world isn't concerned about frequency congestion and airlines are less than enthusiastic about having to have both mod existing 1090 transponders and ALSO install a UAT ADS-B box onboard. Solution: Keep 1090 for aircraft that fly above 18,000 since they are the ones that will encounter the overseas environment.

Isn't it true that most of the RF congestion comes from the bandwidth-intensive interaction of TCAS with Mode C (and earlier) transponders? I've been told that the reason Europe didn't have to go down the UAT (or equivalent) path was because they mandated Mode S. It's possible the US could have done the same, but apparently the FAA didn't want to force a transponder upgrade (which seems silly given all the other mandated equipment and duplicate antennae). And so we get the mess we have that, as you pointed out, the FAA isn't so concerned about because our concerns have little to do with the problems they were solving for.

I remain somewhat skeptical that GA will go en masse to UAT. If Trig comes out with a Mode S/1090ES Out single box that hooks up to an existing Mode C antenna I think it could be quite popular.

Andy

Darryl Ramm

April 7th 15, 08:37 PM

On Tuesday, April 7, 2015 at 10:00:36 AM UTC-7, Andy Blackburn wrote:
> On Tuesday, April 7, 2015 at 9:43:26 AM UTC-7, wrote:
> >
> > Problem: The rest of the world isn't concerned about frequency congestion and airlines are less than enthusiastic about having to have both mod existing 1090 transponders and ALSO install a UAT ADS-B box onboard. Solution: Keep 1090 for aircraft that fly above 18,000 since they are the ones that will encounter the overseas environment.
>
> Isn't it true that most of the RF congestion comes from the bandwidth-intensive interaction of TCAS with Mode C (and earlier) transponders? I've been told that the reason Europe didn't have to go down the UAT (or equivalent) path was because they mandated Mode S. It's possible the US could have done the same, but apparently the FAA didn't want to force a transponder upgrade (which seems silly given all the other mandated equipment and duplicate antennae). And so we get the mess we have that, as you pointed out, the FAA isn't so concerned about because our concerns have little to do with the problems they were solving for.
>
> I remain somewhat skeptical that GA will go en masse to UAT. If Trig comes out with a Mode S/1090ES Out single box that hooks up to an existing Mode C antenna I think it could be quite popular.
>
> Andy

That would be my summary of much of this (and BTW TCAS only interrogates Mode C or S, it won't ever interrogate Mode A and just won't see a Mode A transponder at all). I think a significant part of the issue was the FAA was under pressure from lobbyists like AOPA who wanted to keep Mode C transponders in use. Doing that can cause significant radio frequency congestion issues because of TCAS interrogation of those Mode C transponders, and also makes SSR a little less wonderful than it could be in a pure Mode-S environment. I was never impressed by the technical depth of the arguments used that dual-link was required because of 1090MHz/1030MHz congestion. This at least in part relied on some Monte-Carlo simulation of RF congestion in the LA Basin, but there just never really seemed to be as much academic research and debate as I would have hoped with this. I would have preferred to see wider research, with more broad assumptions/scenarios allowed, all the other mitigation options really well explored, and more academically peer-reviewed studies made before all the cost of a complex dual-link ADS-B system was inflicted on owner/pilots and the US taxpayer.

But anyhow layering complexity on complexity the FAA went dual-link over 109ES and UAT. Then you fold in other agendas like trying to sell UAT to GA aircraft by providing FIS-B data over UAT. Although you only need a cheap UAT-receiver to use FIS-B so it does not really encourage adoption of ADS-Out on either UAT or 1090ES link-layer. And a cynical view was some folks in the FAA just wanted to resurrect the failed FAA FIS (airborne VHF weather data) service. Did we get dual-link becasue of FIS-B or did we get FIS-B because of dual-link? The reality is maybe parts of both. And WX Satellite weather is a better product with better features and wider coverage, especially on the ground pre-flight). But WX Weather requires a paid subscription unlike FIS-B (although you may see paid parts of FIS-B in future from ITT/Excelis). Possible revenue from commercial use of FIS-B is maybe another decision factor in the whole dual-link mess.

The FAA's reasoning about inducements and expectations around using UAT for GA aircraft never made sense to me. Newer aircraft have Mode-S transponders that can be upgraded to 1090ES Out, older aircraft with transponders may be due a transponder upgrade anyhow. So maybe that leaves some in the middle, but that just never seemed like a reason to prioritize "we must keep Mode C" like AOPA pushed for. And the FAA tried to make UAT more widely used by initially allowing use up to FL 240, but that just seemed long-term crazy for things like direct link compatibility with all the big guys flying around in Class A. Once it was clear you were going to needed 1090ES in Class A airspace, then the high-performance singles/light turboprops etc. were all going to go that way, and those owners were more likely to be ADS-B early adopters in the GA space. And once you have some of those folks with 1090ES Out, more of the GA community will follow, both becasue they have GA oriented product available and for direct compatibility with 1090ES Out used by those early adopters.

What the GA lobby should have been pushing for IMNSHO was a usable 1090ES-Only system that would support a usable GA-oriented traffic awareness system.. Or at a minimum some more extensive academic research to validate the claims for need of a dual-link system. End-of-life of Mode-C could have been done over a decade+ time frame. Relying on ground infrastructure to provide ADS-R link-layer translation makes the current ADS-B system a mess for GA traffic awareness. There are too many places of interest to GA where there is not ADS-R coverage, including close to many GA airports and gliderport traffic patterns. And the system is just too complex, still many pilot's don't see to understand they need ADS-B Out to receive ADS-R or TIS-B traffic service.

ADS-B is one of those things that is trying to serve many masters, and as well described in the earlier post, it's really a aircraft surveillance system for the FAA Nextgen project, everything else is really a secondary add-on to try to make it more appealing to other constituents. Hoping I expect from the FAA's view point that those other constituents will then support the adoption of ADS-B, but the only real significant reason the FAA want it is for NextGen surveillance. The poor FAA is stretched thin between powerful constituents and masters, that is largely the US Congress, Airlines, and the occasional whack of a stick from the NTSB. GA gets a small mention every now and again, but the lobbying from various owner/pilot organizations for things related to ADS-B seems to have been pretty confused and/or ineffective. And some of the folks lobbying for those organizations I've spoken to clearly did not understand the technology at a useful level. And its arguable that the FAA was in a tough situation, with NextGen very underfunded, but either way, that is certainly what is really driving ADS-B.

Meanwhile Europe looked at the 1090MHz/1030MHz congestion issue, they have airspace like over Paris where this was a concern (but yes still less ongestion than some US locations). Europe went Mode-S only, which largely solved the TCAS bandwidth problem as TCAS can do selective interrogation of one transponder at a time. And TCAS-II can also save bandwidth by reducing interrogation of a target aircraft if it can be tracked via 1090ES.... but it still hammers away at it with transponder interrogations if it thinks it is a real threat... (oh the irony that that 1090/1030MHz bandwidth saving trick does not work against a target with Mode C/UAT-Out). And their are other options for future like tweaking TCAS power levels to trade off range/congestion. I certainly don't think it is absolutely clear that the FAA *had* to go dual-link with ADS-B becasue of bandwidth.

Heck, if lots of folks don't go Mode-S/1090ES out and stick instead with Mode-C and TCAS use increases it might even be possible that at some point in the future the FAA has to come back and end of life Mode C anyhow. But maybe that possibility is so long off that natural aircraft and Mode C transponder attrition/replacement will prevent that happening.

Head hurting yet? Go crack a beer and dream about your next glider flight.....

Mike Schumann[_2_]

April 8th 15, 02:05 AM

On Tuesday, April 7, 2015 at 3:37:23 PM UTC-4, Darryl Ramm wrote:
> On Tuesday, April 7, 2015 at 10:00:36 AM UTC-7, Andy Blackburn wrote:
> > On Tuesday, April 7, 2015 at 9:43:26 AM UTC-7, wrote:
> > >
> > > Problem: The rest of the world isn't concerned about frequency congestion and airlines are less than enthusiastic about having to have both mod existing 1090 transponders and ALSO install a UAT ADS-B box onboard. Solution: Keep 1090 for aircraft that fly above 18,000 since they are the ones that will encounter the overseas environment.
> >
> > Isn't it true that most of the RF congestion comes from the bandwidth-intensive interaction of TCAS with Mode C (and earlier) transponders? I've been told that the reason Europe didn't have to go down the UAT (or equivalent) path was because they mandated Mode S. It's possible the US could have done the same, but apparently the FAA didn't want to force a transponder upgrade (which seems silly given all the other mandated equipment and duplicate antennae). And so we get the mess we have that, as you pointed out, the FAA isn't so concerned about because our concerns have little to do with the problems they were solving for.
> >
> > I remain somewhat skeptical that GA will go en masse to UAT. If Trig comes out with a Mode S/1090ES Out single box that hooks up to an existing Mode C antenna I think it could be quite popular.
> >
> > Andy
>
> That would be my summary of much of this (and BTW TCAS only interrogates Mode C or S, it won't ever interrogate Mode A and just won't see a Mode A transponder at all). I think a significant part of the issue was the FAA was under pressure from lobbyists like AOPA who wanted to keep Mode C transponders in use. Doing that can cause significant radio frequency congestion issues because of TCAS interrogation of those Mode C transponders, and also makes SSR a little less wonderful than it could be in a pure Mode-S environment. I was never impressed by the technical depth of the arguments used that dual-link was required because of 1090MHz/1030MHz congestion. This at least in part relied on some Monte-Carlo simulation of RF congestion in the LA Basin, but there just never really seemed to be as much academic research and debate as I would have hoped with this. I would have preferred to see wider research, with more broad assumptions/scenarios allowed, all the other mitigation options really well explored, and more academically peer-reviewed studies made before all the cost of a complex dual-link ADS-B system was inflicted on owner/pilots and the US taxpayer.
>
> But anyhow layering complexity on complexity the FAA went dual-link over 109ES and UAT. Then you fold in other agendas like trying to sell UAT to GA aircraft by providing FIS-B data over UAT. Although you only need a cheap UAT-receiver to use FIS-B so it does not really encourage adoption of ADS-Out on either UAT or 1090ES link-layer. And a cynical view was some folks in the FAA just wanted to resurrect the failed FAA FIS (airborne VHF weather data) service. Did we get dual-link becasue of FIS-B or did we get FIS-B because of dual-link? The reality is maybe parts of both. And WX Satellite weather is a better product with better features and wider coverage, especially on the ground pre-flight). But WX Weather requires a paid subscription unlike FIS-B (although you may see paid parts of FIS-B in future from ITT/Excelis). Possible revenue from commercial use of FIS-B is maybe another decision factor in the whole dual-link mess.
>
> The FAA's reasoning about inducements and expectations around using UAT for GA aircraft never made sense to me. Newer aircraft have Mode-S transponders that can be upgraded to 1090ES Out, older aircraft with transponders may be due a transponder upgrade anyhow. So maybe that leaves some in the middle, but that just never seemed like a reason to prioritize "we must keep Mode C" like AOPA pushed for. And the FAA tried to make UAT more widely used by initially allowing use up to FL 240, but that just seemed long-term crazy for things like direct link compatibility with all the big guys flying around in Class A. Once it was clear you were going to needed 1090ES in Class A airspace, then the high-performance singles/light turboprops etc. were all going to go that way, and those owners were more likely to be ADS-B early adopters in the GA space. And once you have some of those folks with 1090ES Out, more of the GA community will follow, both becasue they have GA oriented product available and for direct compatibility with 1090ES Out used by those early adopters.
>
> What the GA lobby should have been pushing for IMNSHO was a usable 1090ES-Only system that would support a usable GA-oriented traffic awareness system. Or at a minimum some more extensive academic research to validate the claims for need of a dual-link system. End-of-life of Mode-C could have been done over a decade+ time frame. Relying on ground infrastructure to provide ADS-R link-layer translation makes the current ADS-B system a mess for GA traffic awareness. There are too many places of interest to GA where there is not ADS-R coverage, including close to many GA airports and gliderport traffic patterns. And the system is just too complex, still many pilot's don't see to understand they need ADS-B Out to receive ADS-R or TIS-B traffic service.
>
> ADS-B is one of those things that is trying to serve many masters, and as well described in the earlier post, it's really a aircraft surveillance system for the FAA Nextgen project, everything else is really a secondary add-on to try to make it more appealing to other constituents. Hoping I expect from the FAA's view point that those other constituents will then support the adoption of ADS-B, but the only real significant reason the FAA want it is for NextGen surveillance. The poor FAA is stretched thin between powerful constituents and masters, that is largely the US Congress, Airlines, and the occasional whack of a stick from the NTSB. GA gets a small mention every now and again, but the lobbying from various owner/pilot organizations for things related to ADS-B seems to have been pretty confused and/or ineffective. And some of the folks lobbying for those organizations I've spoken to clearly did not understand the technology at a useful level. And its arguable that the FAA was in a tough situation, with NextGen very underfunded, but either way, that is certainly what is really driving ADS-B.
>
> Meanwhile Europe looked at the 1090MHz/1030MHz congestion issue, they have airspace like over Paris where this was a concern (but yes still less ongestion than some US locations). Europe went Mode-S only, which largely solved the TCAS bandwidth problem as TCAS can do selective interrogation of one transponder at a time. And TCAS-II can also save bandwidth by reducing interrogation of a target aircraft if it can be tracked via 1090ES.... but it still hammers away at it with transponder interrogations if it thinks it is a real threat... (oh the irony that that 1090/1030MHz bandwidth saving trick does not work against a target with Mode C/UAT-Out). And their are other options for future like tweaking TCAS power levels to trade off range/congestion. I certainly don't think it is absolutely clear that the FAA *had* to go dual-link with ADS-B becasue of bandwidth.
>
> Heck, if lots of folks don't go Mode-S/1090ES out and stick instead with Mode-C and TCAS use increases it might even be possible that at some point in the future the FAA has to come back and end of life Mode C anyhow. But maybe that possibility is so long off that natural aircraft and Mode C transponder attrition/replacement will prevent that happening.
>
> Head hurting yet? Go crack a beer and dream about your next glider flight.....

A little bit of history is important to understand how we got into this mess. ADS-B was originally developed by MITRE to improve situational awareness for General Aviation and to provide an economical alternative to traditional radar coverage in remote areas, like Alaska.

MITRE made the decision to start with a clean sheet design to address two basic issues: 1. To come up with a low power low cost hardware platform, and 2. To provide the bandwidth to support a wide variety of services as the system evolved.

This resulted in the UAT design, which was extensively tested in Alaska as part of the multi-year Capstone project. The FAA paid for equipping about 100 aircraft with ADS-B IN and OUT hardware and moving map displays. The initial product roll-out included Weather and TIS-B. During the test period, there was a dramatic drop in the frequency of fatal GA accidents in the test area, which got the attention of the FAA bureaucrats.

Instead of rolling out this low cost technology as a way to improve situational awareness for the GA fleet, someone came up with the bright idea that this would be a great way to provide high resolution position reporting for IFR aircraft, which would permit the dismantling of a very expensive conventional radar system, while simultaneously providing the accuracy necessary to support simultaneous parallel approaches at major airports in minimal visibility conditions.

That's when the whole program got perverted. The FAA insisted that all ADS-B OUT systems need to have GPS position sources that were FAA certified and provided integrity signals that are not part of any commercial GPS chip sets. As a result, instead of having a $10 GPS receiver, ADS-B OUT systems were required to incorporate $1,500 certified position sources.

The FAA's idiocy is clearly demonstrated by their unwillingness to relax the specs for VFR aircraft who have no desire to enter Class B airspace. The rules for gliders are even more bizarre. Under the rules, we don't need anything to makes us visible (transponders or ADS-B OUT). However, if we voluntarily equip with ADS-B we have to meet the gold plated IFR specs. The bottom line, is that the FAA would rather have a glider flying around invisible, than permit the installation of a low cost non-certified piece of hardware that might not meet their big iron standards.

Darryl Ramm

April 8th 15, 07:55 PM

Mike Schumann > wrote:
> On Tuesday, April 7, 2015 at 11:00:15 PM UTC-4, Darryl Ramm wrote:
>>>> On Tuesday, April 7, 2015 at 3:37:23 PM UTC-4, Darryl Ramm wrote:
>>>> On Tuesday, April 7, 2015 at 10:00:36 AM UTC-7, Andy Blackburn wrote:
>>>>> On Tuesday, April 7, 2015 at 9:43:26 AM UTC-7, wrote:
>>>>>>
>>>>>> Problem: The rest of the world isn't concerned about frequency
>>>>>> congestion and airlines are less than enthusiastic about having to
>>>>>> have both mod existing 1090 transponders and ALSO install a UAT ADS-B
>>>>>> box onboard. Solution: Keep 1090 for aircraft that fly above 18,000
>>>>>> since they are the ones that will encounter the overseas environment.
>>>>>
>>>>> Isn't it true that most of the RF congestion comes from the
>>>>> bandwidth-intensive interaction of TCAS with Mode C (and earlier)
>>>>> transponders? I've been told that the reason Europe didn't have to go
>>>>> down the UAT (or equivalent) path was because they mandated Mode S.
>>>>> It's possible the US could have done the same, but apparently the FAA
>>>>> didn't want to force a transponder upgrade (which seems silly given all
>>>>> the other mandated equipment and duplicate antennae). And so we get the
>>>>> mess we have that, as you pointed out, the FAA isn't so concerned about
>>>>> because our concerns have little to do with the problems they were solving for.
>>>>>
>>>>> I remain somewhat skeptical that GA will go en masse to UAT. If Trig
>>>>> comes out with a Mode S/1090ES Out single box that hooks up to an
>>>>> existing Mode C antenna I think it could be quite popular.
>>>>>
>>>>> Andy
>>>>
>>>> That would be my summary of much of this (and BTW TCAS only interrogates
>>>> Mode C or S, it won't ever interrogate Mode A and just won't see a Mode
>>>> A transponder at all). I think a significant part of the issue was the
>>>> FAA was under pressure from lobbyists like AOPA who wanted to keep Mode
>>>> C transponders in use. Doing that can cause significant radio frequency
>>>> congestion issues because of TCAS interrogation of those Mode C
>>>> transponders, and also makes SSR a little less wonderful than it could
>>>> be in a pure Mode-S environment. I was never impressed by the technical
>>>> depth of the arguments used that dual-link was required because of
>>>> 1090MHz/1030MHz congestion. This at least in part relied on some
>>>> Monte-Carlo simulation of RF congestion in the LA Basin, but there just
>>>> never really seemed to be as much academic research and debate as I
>>>> would have hoped with this. I would have preferred to see wider
>>>> research, with more broad assumptions/scenarios allowed, all the other
>>>> mitigation options really well explored, and more academically
>>>> peer-reviewed studies made before all the cost of a complex dual-link
>>>> ADS-B system was inflicted on owner/pilots and the US taxpayer.
>>>>
>>>> But anyhow layering complexity on complexity the FAA went dual-link over
>>>> 109ES and UAT. Then you fold in other agendas like trying to sell UAT
>>>> to GA aircraft by providing FIS-B data over UAT. Although you only need
>>>> a cheap UAT-receiver to use FIS-B so it does not really encourage
>>>> adoption of ADS-Out on either UAT or 1090ES link-layer. And a cynical
>>>> view was some folks in the FAA just wanted to resurrect the failed FAA
>>>> FIS (airborne VHF weather data) service. Did we get dual-link becasue of
>>>> FIS-B or did we get FIS-B because of dual-link? The reality is maybe
>>>> parts of both. And WX Satellite weather is a better product with better
>>>> features and wider coverage, especially on the ground pre-flight). But
>>>> WX Weather requires a paid subscription unlike FIS-B (although you may
>>>> see paid parts of FIS-B in future from ITT/Excelis). Possible revenue
>>>> from commercial use of FIS-B is maybe another decision factor in the
>>>> whole dual-link mess.
>>>>
>>>> The FAA's reasoning about inducements and expectations around using UAT
>>>> for GA aircraft never made sense to me. Newer aircraft have Mode-S
>>>> transponders that can be upgraded to 1090ES Out, older aircraft with
>>>> transponders may be due a transponder upgrade anyhow. So maybe that
>>>> leaves some in the middle, but that just never seemed like a reason to
>>>> prioritize "we must keep Mode C" like AOPA pushed for. And the FAA tried
>>>> to make UAT more widely used by initially allowing use up to FL 240, but
>>>> that just seemed long-term crazy for things like direct link
>>>> compatibility with all the big guys flying around in Class A. Once it
>>>> was clear you were going to needed 1090ES in Class A airspace, then the
>>>> high-performance singles/light turboprops etc. were all going to go that
>>>> way, and those owners were more likely to be ADS-B early adopters in the
>>>> GA space. And once you have some of those folks with 1090ES Out, more of
>>>> the GA community will follow, both becasue they have GA oriented product
>>>> available and for direct compatibility with 1090ES Out used by those early adopters.
>>>>
>>>> What the GA lobby should have been pushing for IMNSHO was a usable
>>>> 1090ES-Only system that would support a usable GA-oriented traffic
>>>> awareness system. Or at a minimum some more extensive academic research
>>>> to validate the claims for need of a dual-link system. End-of-life of
>>>> Mode-C could have been done over a decade+ time frame. Relying on ground
>>>> infrastructure to provide ADS-R link-layer translation makes the current
>>>> ADS-B system a mess for GA traffic awareness. There are too many places
>>>> of interest to GA where there is not ADS-R coverage, including close to
>>>> many GA airports and gliderport traffic patterns. And the system is just
>>>> too complex, still many pilot's don't see to understand they need ADS-B
>>>> Out to receive ADS-R or TIS-B traffic service.
>>>>
>>>> ADS-B is one of those things that is trying to serve many masters, and
>>>> as well described in the earlier post, it's really a aircraft
>>>> surveillance system for the FAA Nextgen project, everything else is
>>>> really a secondary add-on to try to make it more appealing to other
>>>> constituents. Hoping I expect from the FAA's view point that those other
>>>> constituents will then support the adoption of ADS-B, but the only real
>>>> significant reason the FAA want it is for NextGen surveillance. The poor
>>>> FAA is stretched thin between powerful constituents and masters, that is
>>>> largely the US Congress, Airlines, and the occasional whack of a stick
>>>> from the NTSB. GA gets a small mention every now and again, but the
>>>> lobbying from various owner/pilot organizations for things related to
>>>> ADS-B seems to have been pretty confused and/or ineffective. And some of
>>>> the folks lobbying for those organizations I've spoken to clearly did
>>>> not understand the technology at a useful level. And its arguable that
>>>> the FAA was in a tough situation, with NextGen very underfunded, but
>>>> either way, that is certainly what is really driving ADS-B.
>>>>
>>>> Meanwhile Europe looked at the 1090MHz/1030MHz congestion issue, they
>>>> have airspace like over Paris where this was a concern (but yes still
>>>> less ongestion than some US locations). Europe went Mode-S only, which
>>>> largely solved the TCAS bandwidth problem as TCAS can do selective
>>>> interrogation of one transponder at a time. And TCAS-II can also save
>>>> bandwidth by reducing interrogation of a target aircraft if it can be
>>>> tracked via 1090ES.... but it still hammers away at it with transponder
>>>> interrogations if it thinks it is a real threat... (oh the irony that
>>>> that 1090/1030MHz bandwidth saving trick does not work against a target
>>>> with Mode C/UAT-Out). And their are other options for future like
>>>> tweaking TCAS power levels to trade off range/congestion. I certainly
>>>> don't think it is absolutely clear that the FAA *had* to go dual-link
>>>> with ADS-B becasue of bandwidth.
>>>>
>>>> Heck, if lots of folks don't go Mode-S/1090ES out and stick instead with
>>>> Mode-C and TCAS use increases it might even be possible that at some
>>>> point in the future the FAA has to come back and end of life Mode C
>>>> anyhow. But maybe that possibility is so long off that natural aircraft
>>>> and Mode C transponder attrition/replacement will prevent that happening.
>>>>
>>>> Head hurting yet? Go crack a beer and dream about your next glider flight....
>>>
>>> A little bit of history is important to understand how we got into this
>>> mess. ADS-B was originally developed by MITRE to improve situational
>>> awareness for General Aviation and to provide an economical alternative
>>> to traditional radar coverage in remote areas, like Alaska.
>>>
>>> MITRE made the decision to start with a clean sheet design to address two
>>> basic issues: 1. To come up with a low power low cost hardware
>>> platform, and 2. To provide the bandwidth to support a wide variety of
>>> services as the system evolved.
>>>
>>> This resulted in the UAT design, which was extensively tested in Alaska
>>> as part of the multi-year Capstone project. The FAA paid for equipping
>>> about 100 aircraft with ADS-B IN and OUT hardware and moving map
>>> displays. The initial product roll-out included Weather and TIS-B.
>>> During the test period, there was a dramatic drop in the frequency of
>>> fatal GA accidents in the test area, which got the attention of the FAA bureaucrats.
>>>
>>> Instead of rolling out this low cost technology as a way to improve
>>> situational awareness for the GA fleet, someone came up with the bright
>>> idea that this would be a great way to provide high resolution position
>>> reporting for IFR aircraft, which would permit the dismantling of a very
>>> expensive conventional radar system, while simultaneously providing the
>>> accuracy necessary to support simultaneous parallel approaches at major
>>> airports in minimal visibility conditions.
>>>
>>> That's when the whole program got perverted. The FAA insisted that all
>>> ADS-B OUT systems need to have GPS position sources that were FAA
>>> certified and provided integrity signals that are not part of any
>>> commercial GPS chip sets. As a result, instead of having a $10 GPS
>>> receiver, ADS-B OUT systems were required to incorporate $1,500
>>> certified position sources.
>>>
>>> The FAA's idiocy is clearly demonstrated by their unwillingness to relax
>>> the specs for VFR aircraft who have no desire to enter Class B airspace.
>>> The rules for gliders are even more bizarre. Under the rules, we don't
>>> need anything to makes us visible (transponders or ADS-B OUT). However,
>>> if we voluntarily equip with ADS-B we have to meet the gold plated IFR
>>> specs. The bottom line, is that the FAA would rather have a glider
>>> flying around invisible, than permit the installation of a low cost
>>> non-certified piece of hardware that might not meet their big iron standards.
>>
>> Mitre was involved with lots of ADS-B work but they did not "invent ADS-B".
>> Maybe you meant UAT. Which they did more drive. And ADS-B was not primarily
>> developed as a GA collision avoidance technology--maybe some engineers felt
>> it was but the FAA was paying for this development and back in the early
>> 1990s they were clearly already pushing it primarily as a future
>> surveillance technology. And that is how the FAA sold it to Congress and it
>> got funded.
>>
>> ADS-B is a broad industry wide technology development with by far the
>> largest interest in it being for ATC surveillance.
>>
>> You and Bernald Smith seem to be the US Soaring sales reps for Mitre and
>> their UAT technology. All that has resulted from all the talk over many
>> years is... exactly nothing. Not one single useful thing. Except time
>> wasted, potential users confused and in some cases a decrease in safety as
>> some people put off adopting other technology.
>>
>> The Capstone project heavily involved ATC ADS-B based surveillance in an
>> area that had no SSR coverage, it was funded and managed by the FAA as a
>> *surveillance project*. the FAA attributed the increase in safety due to
>> improved *surveillance* and used that to justify ADS-B and NextGen funding.
>> Good luck finding much mention of cockpit traffic systems buried well below
>> the FAAs focus on Capstone surveillance. e.g.
>> http://www.faa.gov/news/fact_sheets/news_story.cfm?newsIdy57
>>
>> UAT was a mistake that should have been shot through the head by the FAA.
>> And the glaring problems of lack of TCAS compatibility should have made it
>> a non-starter for any use in gliders. Instead the US Soaring community has
>> had years of folks hyping this crap, and making people think there is
>> likely to be some new UAT box around the corner. And in some locations that
>> may have had an impact on safety by discouraging glider owners to install
>> transponders. We had some pilots who put off installing transponders in the
>> Reno area thinking UAT technology was coming and would be very low-cost.
>> Now maybe they were never actually going to install anything and UAT
>> futureware was just a convenient excuse. Luckily many more pilots in that
>> area behaved more responsibly.
>
> Your constant labeling of UAT as "crap" is pretty insulting to a lot of
> very bright people in MITRE and to our fellow glider pilot Bernald Smith,
> who had the vision to try to introduce a state of the art technology to
> replace the antiquated World War II vintage architecture that provides
> the basis for current Mode C and Mode S transponders.
>
> It is unfortunate that these folks couldn't get the FAA to see the long
> term advantages of this approach and provide a clear migration plan to
> incorporate ADS-B into the TCAS architecture, so that conventional
> transponders could eventually be retired. Because the FAA couldn't get
> their act together on a long term migration plan, we are now stuck with
> an overly complicated dual frequency system which will still require
> aircraft to be transponder equipped into the indefinite future.
>
> Your assertion that the development of UAT has resulted in "not one
> single useful thing" is complete BS. There are thousands of pilots who
> are currently buying low cost UAT based ADS-B receivers. While the
> traffic data provided by these receivers is only useful if the A/C is
> ADS-B OUT equipped, these units provide free weather and notam data. I
> would be willing to wager that Sporty's has sold at least 10x as many
> Stratus ADS-B receivers over the last couple of years than the number of
> POWERFLARM systems sold in the US.
>
> The frustrations that you espouse have their roots, not in misinformation
> that I and others are providing to the pilot community, but rather the
> result of people recognizing POWERFLARM's limitations on displaying
> non-glider traffic. There are a lot of people who don't want to waste
> their money on a product that has a half baked ADS-B IN implementation
> that is not going to be able to identify ADS-B UAT equipped aircraft.
>
> If the POWERFLARM folks want to stay in the game, they need to
> incorporate a dual frequency ADS-B receiver and/or support TIS-B. If
> that happens, people like me will shut up, and maybe even buy the product.

What I said was all the Mitre salesmanship and pro UAT-hype from folks like
Bernald and you have not resulted in anything at all of use/benefit to the
soaring community. Is that clear enough? And yes I know, the reasons why
that is will be entirely somebody else's fault...

And I am certainly not pushing FLARM, for the apparently serious glider-GA
traffic midair collision risks like you have described with the Minnesota
Soaring Club operating under a Mode C veil it might be that transponder
carriage would be more useful, maybe in collaboration with FAA ATC
procedures/awareness. Maybe PCAS and 1090 ES in in PowerFLARM would help. I
would hope that if safety issues there are as serious as you make out that
pragmatic people would have long since been looking at what is actually
usable/doable to minimize mid-air collision risks, wether that is
awareness, training, procedures, reaching out to the FAA or GA community,
use of practical technology etc. So what has the club done?

All I think we ever hear about is you raising concerns, over many years
about the mid-air collision risk there, and how there is apparently nothing
technically available that would be a practical help with these safety
concerns--although lots of other owners, clubs etc. seem to somehow find
that Zaon and other PCAS, PowerFLARM and/or transponders were very
effective practical aids for their environments. Hopefully the Minnesota
Soaring Club has not just spent years waiting and hoping for some mythical
low cost UAT based solution and/or used that as an excuse not to adopt
*any* technology to help with as you describe it a serious glider-GA
mid-air collision risk.

Mike Schumann[_2_]

April 8th 15, 09:52 PM

On Wednesday, April 8, 2015 at 2:56:24 PM UTC-4, Darryl Ramm wrote:
> Mike Schumann wrote:
> > On Tuesday, April 7, 2015 at 11:00:15 PM UTC-4, Darryl Ramm wrote:
> >>>> On Tuesday, April 7, 2015 at 3:37:23 PM UTC-4, Darryl Ramm wrote:
> >>>> On Tuesday, April 7, 2015 at 10:00:36 AM UTC-7, Andy Blackburn wrote:
> >>>>> On Tuesday, April 7, 2015 at 9:43:26 AM UTC-7, wrote:
> >>>>>>
> >>>>>> Problem: The rest of the world isn't concerned about frequency
> >>>>>> congestion and airlines are less than enthusiastic about having to
> >>>>>> have both mod existing 1090 transponders and ALSO install a UAT ADS-B
> >>>>>> box onboard. Solution: Keep 1090 for aircraft that fly above 18,000
> >>>>>> since they are the ones that will encounter the overseas environment.

[email protected]

April 8th 15, 10:39 PM

On Wednesday, April 8, 2015 at 11:56:24 AM UTC-7, Darryl Ramm wrote:
> What I said was all the Mitre salesmanship and pro UAT-hype from folks like
> Bernald and you have not resulted in anything at all of use/benefit to the
> soaring community. Is that clear enough? And yes I know, the reasons why
> that is will be entirely somebody else's fault...

Darryl, there was a lot of interesting discussion going on in ancient times (you know, before PowerFlarm, 8 or 9 years ago). As I remember it, Bernald was pushing UAT back then because there was a lot of concern about the possibility of glider vs. airliner collisions, and at the time, UAT seemed like it was going to be a good way of getting gliders, ultralights, balloons, etc., integrated into the air traffic system at low cost and with minimal power consumption. The icing on the cake was the Mitre UAT ADS-B out prototypes, that were basically built using $100 or so worth of cellphone chipsets and COTS GPS modules, and could run all day on a few AA cells. I know Mike was involved in the successful testing of these units in gliders and powered aircraft in the Virginia area (if I remember correctly). This was a promising technology with a lot of support even from groups within the FAA, with the end goal being pervasive use of UAT-based ADS-B technology in UAVs, general aviation, and gliders. The general understanding at the time was that these units would eliminate the need for transponders for general aviation. But, one should never underestimate the capability of the FAA to create a steaming pile out of a nice clean solution.

I also remember that it was Bernald who introduced Urs to various parties in the US soaring community (myself included), with the explicit intent of bring Flarm into this country. In particular I was present at a number of informal discussions that took place around the '08 SSA convention that were set up by Bernald, which (again, if I remember correctly) led to the notion of PowerFlarm, the Flarm loaner/rental program, and other such things. It's funny how you've now decided that he is nothing more than a misguided salesman.

Marc

Andrzej Kobus

April 9th 15, 12:05 AM

Here is a good one. I bet sooner or later FAA will give up and allow the lower cost units.

http://www.flyingmag.com/avionics-gear/instrumentaccessories/ads-b-compliance-699-its-true-sort

My next glider coming out of factory will have Trig T22 with FreeFlight 1201 installed (experimental) as well as ADSB-in (both bands).

I have PowerFlarm in my current glider and I am not certain I want one again due to huge number of nuisance alarms coming from my own Trig T22 transponder. I might give it a try again, but ... if it behaves the same way as the current unit it will be out of my glider faster than it came in. I did contact support without any resolution. In fact I had my PowerFlarm unit in two gliders both equipped with Mod S transponders and I had tons of nuisance alarms in both gliders. Transponder output was tested and PowerFlram antennas were mounted properly.

I also hear from folks in Europe about ADS-B out and PowerFlarm installed in the same aircraft not working properly.

I admit at some point in the past I wanted PowerFlarm to be mandatory for contests. I am not sure about that anymore.

Yes, in contest environment I benefited from PowerFlarm, but I also acknowledge there were many false positives in thermals that caused me to interrupt my scanning procedure to check on potentially conflicting traffic.
I remember busy thermals when the thing would not shut up at all. I have been using PowerFlarm since it showed up in the US.

Sometimes a simple thing like a strobe light on a glider can be very effective in making a glider visible.

At the end it is only important to know there are people around me before they get to close after that is your head on you neck that matters. If everyone had a UAT for $699 it would work for us too. I just need to know there is someone coming. Then add a transponder for the heavy machines and you are all set.

I really don't care for PowerFlarm algorithm speed as speed only matters when the traffic is very close. At that point I should have it already visible. You don't want to react when you have a second. You want to know the traffic is coming and react much earlier. You should never need the fast reaction time.

I don't think ADS-B vs. PowerFlarm is such a clear cut. I bet sales of Flarm units in Europe will fall as a result of easy ADS-B out and $200 ADS-B in hardware available.

Darryl Ramm

April 9th 15, 12:11 AM

On Wednesday, April 8, 2015 at 2:39:23 PM UTC-7, wrote:
> On Wednesday, April 8, 2015 at 11:56:24 AM UTC-7, Darryl Ramm wrote:
> > What I said was all the Mitre salesmanship and pro UAT-hype from folks like
> > Bernald and you have not resulted in anything at all of use/benefit to the
> > soaring community. Is that clear enough? And yes I know, the reasons why
> > that is will be entirely somebody else's fault...
>
> Darryl, there was a lot of interesting discussion going on in ancient times (you know, before PowerFlarm, 8 or 9 years ago). As I remember it, Bernald was pushing UAT back then because there was a lot of concern about the possibility of glider vs. airliner collisions, and at the time, UAT seemed like it was going to be a good way of getting gliders, ultralights, balloons, etc., integrated into the air traffic system at low cost and with minimal power consumption. The icing on the cake was the Mitre UAT ADS-B out prototypes, that were basically built using $100 or so worth of cellphone chipsets and COTS GPS modules, and could run all day on a few AA cells. I know Mike was involved in the successful testing of these units in gliders and powered aircraft in the Virginia area (if I remember correctly). This was a promising technology with a lot of support even from groups within the FAA, with the end goal being pervasive use of UAT-based ADS-B technology in UAVs, general aviation, and gliders. The general understanding at the time was that these units would eliminate the need for transponders for general aviation. But, one should never underestimate the capability of the FAA to create a steaming pile out of a nice clean solution.
>
> I also remember that it was Bernald who introduced Urs to various parties in the US soaring community (myself included), with the explicit intent of bring Flarm into this country. In particular I was present at a number of informal discussions that took place around the '08 SSA convention that were set up by Bernald, which (again, if I remember correctly) led to the notion of PowerFlarm, the Flarm loaner/rental program, and other such things. It's funny how you've now decided that he is nothing more than a misguided salesman.
>
> Marc

Marc

And pushing UAT-Out futures for use in areas where airliners were a concern, like the Reno area, seemed to ignore the issue of lack of TCAS compatibility. And promised folks the hope of low-cost and easy to install UAT-Out devices when many should have been considering installing transpodners. it always just scared the hell out of me, to see this promoted as a goal at all, especially for areas like the Reno area, where TCAS II equipped traffic is such an issue.

I sat through at least one PASCO seminar from Bernald and another given by you where some folks who attended took away that they won't be installing transponders but waiting for these UAT devices. I certainly remember one-post UAT presentation discussion with glider owners from the Reno area who were absolutely in love with this soon to be coming $500 portable box and totally opposed to istalling a $3,000 "power hungry" transponder. Many folks clearly took away far more than they shoudl have about the actual state of play of any of this stuff, and few if any really understood the limitations. Bernald has done may great things for he soaring community and soaring saftey, ultra impressive, but all that effort pushing UAT technology was just a bad idea. And you also have done a huge amount for soaring and soaring saftey, include your work in the Reno area, all fantastic stuff.

And I think it was probalby you, indirectly through Benrald, that introduced me to Urs. Maybe after a seminar I had given on transponders, ADS-B and FLARM, ... partially with the goal of discouraging folks trying to import and use overseas-FLARM units, which was a bit of an underground idea going around at the time (including a few physical units kicking around). I've been happy to help the Flarm guys on some stuff when asked, but have done far far less there than many others in the USA who wanted to see this technology available for the Soaring Community.

After that UAT promotion that was happening in the PASCO seminars I started giving presentations about glider batteries etc. if folks were worried about battery issues with transponders I certainly wanted them to know enough to have a cogent discussion. And I started to speak up in PASCO seminars etc. about the TCAS compatibility issue, I don't recall that was ever mentioned before, I could be wrong on that, but I never heard it raised. UAT-Out only adoption in the Reno area would gave been a very bad move, getting anything to happen with high tech/aviation/avionics is damn hard, but starting off trying to get something to happen that if it did succeed would be bad, is not a good idea.

The final straw for me with all the UAT hype came the day I was flying out of Minden and the Hawker 800 collided with an ASG-29. I was at the other end of the Pinenut ranges when that happened. And one bizarre response to that was some folks talking up yet again the hope/need to UAT-Out devices. Jesus, TCAS-II equipped business jet, colliding with a glider with it's transponder turned off... what could people *not* get about that? Luckily most folks took that as a need to keep focusing on transponder use in that area.

I doubt the establishment of PowerFLARM rental programs in the USA had any practical help from Bernald, what made that happen was Williams Soaring and generous donors actually stepping up and making that happen.

I don't care if anybody use any particular traffic-awareness technology, but I hope that people at least evaluate what might help them. I'd hate for example to see say the glider exemption for transponders or ADS-B Out to be lost in future, that would be just a horrible waste for many gliders in many locations. In other locations where there are traffic concerns I hope owners/pilots/clubs/FBOs are looking at all the things that it is possible to do to reduce mid-air collision risks. And I care when others keep presenting misinformation/spurious arguments about might prevent some folks adopting what technology aids are practically available today.

Andrew[_13_]

April 9th 15, 01:17 AM

At 02:01 26 March 2015, Darryl Ramm wrote:
>Maybe next time try searching r.a.s. before asking a question. You
would
>have found this has been covered in depth here recently...
>

is there a way to search r.a.s for keywords?

Bob Pasker

April 9th 15, 01:27 AM

On Monday, April 6, 2015 at 7:19:19 PM UTC-4, kirk.stant wrote:
> Now, what we figured happened is: 1. Our transponder was stuck putting out a bad altitude (2400ft) instead of the actual pressure alt (about 9400ft)

did the transponder in that plane display pressure altitude, like my KTX-76? if so, did it show the wrong altitude? the right altitude? and when you realized what happened, did you call approach or center and ask for an altimeter readout?

http://www.bendixking.com/Products/Navigation-Communication/Transponders/KT-76C

Darryl Ramm

April 9th 15, 02:18 AM

On Wednesday, April 8, 2015 at 5:30:07 PM UTC-7, Andrew wrote:
> At 02:01 26 March 2015, Darryl Ramm wrote:
> >Maybe next time try searching r.a.s. before asking a question. You
> would
> >have found this has been covered in depth here recently...
> >
>
>
> is there a way to search r.a.s for keywords?

Remember that r.a.s is a USENET forum which means a distributed network of servers carrying all this stuff, and what you can or can't do with messages is largely dependent on the client you are using to access that USENET newsgroup. It looks like are posting from the Glider Pilot Network, I'm not sure what is provided there. Maybe others can help you.

Most USENET NNTP clients (like Mozilla Thunderbird) provide good local search capabilities, which means you can search on just about anything in the messages that are downloaded to your client. It can also search on things based on header fields on the server. And you can also do some pretty complex filtering based on fields, which may be useful for finding posts.

Google Groups also provides good Web based search. Go to the "Search for topics" field and pull down the small down-arrow. There is more search capabilities hidden there... make sure you scroll all the way down in the search window that appears, you can search for keywords in the whole article using the "Has the words" field, that is not just searching the Subject field as the UI might seem to suggest.

Really advanced search is available to folks who have direct access to a USENET server. and want to custom write code :-) But that type of search is rarely needed.

Mike Schumann[_2_]

April 9th 15, 04:55 AM

On Wednesday, April 8, 2015 at 7:11:20 PM UTC-4, Darryl Ramm wrote:
> On Wednesday, April 8, 2015 at 2:39:23 PM UTC-7, wrote:
> > On Wednesday, April 8, 2015 at 11:56:24 AM UTC-7, Darryl Ramm wrote:
> > > What I said was all the Mitre salesmanship and pro UAT-hype from folks like
> > > Bernald and you have not resulted in anything at all of use/benefit to the
> > > soaring community. Is that clear enough? And yes I know, the reasons why
> > > that is will be entirely somebody else's fault...
> >
> > Darryl, there was a lot of interesting discussion going on in ancient times (you know, before PowerFlarm, 8 or 9 years ago). As I remember it, Bernald was pushing UAT back then because there was a lot of concern about the possibility of glider vs. airliner collisions, and at the time, UAT seemed like it was going to be a good way of getting gliders, ultralights, balloons, etc., integrated into the air traffic system at low cost and with minimal power consumption. The icing on the cake was the Mitre UAT ADS-B out prototypes, that were basically built using $100 or so worth of cellphone chipsets and COTS GPS modules, and could run all day on a few AA cells. I know Mike was involved in the successful testing of these units in gliders and powered aircraft in the Virginia area (if I remember correctly). This was a promising technology with a lot of support even from groups within the FAA, with the end goal being pervasive use of UAT-based ADS-B technology in UAVs, general aviation, and gliders. The general understanding at the time was that these units would eliminate the need for transponders for general aviation. But, one should never underestimate the capability of the FAA to create a steaming pile out of a nice clean solution.
> >
> > I also remember that it was Bernald who introduced Urs to various parties in the US soaring community (myself included), with the explicit intent of bring Flarm into this country. In particular I was present at a number of informal discussions that took place around the '08 SSA convention that were set up by Bernald, which (again, if I remember correctly) led to the notion of PowerFlarm, the Flarm loaner/rental program, and other such things.. It's funny how you've now decided that he is nothing more than a misguided salesman.
> >
> > Marc
>
> Marc
>
> And pushing UAT-Out futures for use in areas where airliners were a concern, like the Reno area, seemed to ignore the issue of lack of TCAS compatibility. And promised folks the hope of low-cost and easy to install UAT-Out devices when many should have been considering installing transpodners. it always just scared the hell out of me, to see this promoted as a goal at all, especially for areas like the Reno area, where TCAS II equipped traffic is such an issue.
>
> I sat through at least one PASCO seminar from Bernald and another given by you where some folks who attended took away that they won't be installing transponders but waiting for these UAT devices. I certainly remember one-post UAT presentation discussion with glider owners from the Reno area who were absolutely in love with this soon to be coming $500 portable box and totally opposed to istalling a $3,000 "power hungry" transponder. Many folks clearly took away far more than they shoudl have about the actual state of play of any of this stuff, and few if any really understood the limitations.. Bernald has done may great things for he soaring community and soaring saftey, ultra impressive, but all that effort pushing UAT technology was just a bad idea. And you also have done a huge amount for soaring and soaring saftey, include your work in the Reno area, all fantastic stuff.
>
> And I think it was probalby you, indirectly through Benrald, that introduced me to Urs. Maybe after a seminar I had given on transponders, ADS-B and FLARM, ... partially with the goal of discouraging folks trying to import and use overseas-FLARM units, which was a bit of an underground idea going around at the time (including a few physical units kicking around). I've been happy to help the Flarm guys on some stuff when asked, but have done far far less there than many others in the USA who wanted to see this technology available for the Soaring Community.
>
> After that UAT promotion that was happening in the PASCO seminars I started giving presentations about glider batteries etc. if folks were worried about battery issues with transponders I certainly wanted them to know enough to have a cogent discussion. And I started to speak up in PASCO seminars etc. about the TCAS compatibility issue, I don't recall that was ever mentioned before, I could be wrong on that, but I never heard it raised. UAT-Out only adoption in the Reno area would gave been a very bad move, getting anything to happen with high tech/aviation/avionics is damn hard, but starting off trying to get something to happen that if it did succeed would be bad, is not a good idea.
>
> The final straw for me with all the UAT hype came the day I was flying out of Minden and the Hawker 800 collided with an ASG-29. I was at the other end of the Pinenut ranges when that happened. And one bizarre response to that was some folks talking up yet again the hope/need to UAT-Out devices. Jesus, TCAS-II equipped business jet, colliding with a glider with it's transponder turned off... what could people *not* get about that? Luckily most folks took that as a need to keep focusing on transponder use in that area.
>
> I doubt the establishment of PowerFLARM rental programs in the USA had any practical help from Bernald, what made that happen was Williams Soaring and generous donors actually stepping up and making that happen.
>
> I don't care if anybody use any particular traffic-awareness technology, but I hope that people at least evaluate what might help them. I'd hate for example to see say the glider exemption for transponders or ADS-B Out to be lost in future, that would be just a horrible waste for many gliders in many locations. In other locations where there are traffic concerns I hope owners/pilots/clubs/FBOs are looking at all the things that it is possible to do to reduce mid-air collision risks. And I care when others keep presenting misinformation/spurious arguments about might prevent some folks adopting what technology aids are practically available today.

The ultimate goal that MITRE, Bernard, myself, and many other pilots had in promoting the UAT technology was to have a low cost, low power, ADS-B OUT solution that would be inexpensive enough so there would be no reason not to require universal equippage. With the introduction of UAVs into the system, with farmers, power companies, and others using these devices, unmanned drones are going to be everywhere. Even if you are in the middle of nowhere, you are going to have to make yourself electronically visible if you don't want to have some scary encounters down the road.

As far as TCAS goes, this system was designed as the last line of defense if there was a complete breakdown in the ATC system's mission of separating IFR and GA traffic. Unfortunately, the FAA has permitted the controller community to use TCAS as a primary method of separating traffic. Under the current FARs, ATC only provides traffic separation between IFR traffic. Separation between IFR and VFR traffic is the pilots' responsibility, in both aircraft, using visual see and avoid eyeball technology.

The Minden accident was a wakeup call on how well this works. The IFR / VFR visual separation rules date back to the 30s when aircraft where flying around at 100 knots with minimal traffic. The reality is that you can't really see someone in time if you have a closing rate of 300 - 400 knots. Making matters worse, is that most of the time jet pilots have their heads in the cockpits setting up for an approach, assuming that the ATC controllers will keep them out of harms way.

The reality is that if you are lucky, and the workload permits, an ATC controller will give an IFR aircraft a traffic advisory for transponder or ADS-B equipped VFR traffic. It is not necessarily standard procedure for controllers to vector IFR traffic around conflicting GA traffic.

This behavior was documented by an MIT Lincoln Lab study in 2005 monitoring the frequency of TCAS Resolution Advisories in the Boston area, and analyzing how pilots reacted to these events. They observed an average of 9 RAs per day within 60 miles of the Lincoln Labs receiver site. From the data, it appears that at least 30% of these events triggered abrupt evasive maneuvers within seconds of the RA, implying that the pilots had not visually recognized the conflicting traffic prior to the TCAS alarm. See: http://www..ll.mit.edu/publications/journal/pdf/vol16_no2/16_2_04Kuchar.pdf Pages 286-288.

The bottom line is that TCAS RAs should not be happening at all. These events should be treated by the FAA with the same level of concern as runway incursions. Equipping all aircraft with transponders or ADS-B OUT systems alone will not solve the problem. What is needed is a fundamental change in the IFR / VFR separation rules to require ATC controllers to actively vector IFR traffic around conflicting VFR aircraft.

Universal ADS-B OUT equipage would go a long way to providing a practical way to solve this problem. ADS-B IN equipped aircraft would be able to easily see potential conflicting traffic far in advance of any collision threat, when the danger could be completely avoided by a minor course correction.

In the GA world today, these ADS-B IN systems are becoming quite popular and will help GA pilots proactively stay out of the way of conflicting airline traffic. Hopefully the FAA will recognize the safety value of this technology and relax their certification rules so that this technology is available at a reasonable cost, to permit existing jet aircraft operators to voluntarily retrofit their aircraft with this capability.

Darryl Ramm

April 9th 15, 06:00 AM

On Wednesday, April 8, 2015 at 8:55:54 PM UTC-7, Mike Schumann wrote:
> On Wednesday, April 8, 2015 at 7:11:20 PM UTC-4, Darryl Ramm wrote:
> > On Wednesday, April 8, 2015 at 2:39:23 PM UTC-7, wrote:
> > > On Wednesday, April 8, 2015 at 11:56:24 AM UTC-7, Darryl Ramm wrote:
> > > > What I said was all the Mitre salesmanship and pro UAT-hype from folks like
> > > > Bernald and you have not resulted in anything at all of use/benefit to the
> > > > soaring community. Is that clear enough? And yes I know, the reasons why
> > > > that is will be entirely somebody else's fault...
> > >
> > > Darryl, there was a lot of interesting discussion going on in ancient times (you know, before PowerFlarm, 8 or 9 years ago). As I remember it, Bernald was pushing UAT back then because there was a lot of concern about the possibility of glider vs. airliner collisions, and at the time, UAT seemed like it was going to be a good way of getting gliders, ultralights, balloons, etc., integrated into the air traffic system at low cost and with minimal power consumption. The icing on the cake was the Mitre UAT ADS-B out prototypes, that were basically built using $100 or so worth of cellphone chipsets and COTS GPS modules, and could run all day on a few AA cells. I know Mike was involved in the successful testing of these units in gliders and powered aircraft in the Virginia area (if I remember correctly). This was a promising technology with a lot of support even from groups within the FAA, with the end goal being pervasive use of UAT-based ADS-B technology in UAVs, general aviation, and gliders. The general understanding at the time was that these units would eliminate the need for transponders for general aviation. But, one should never underestimate the capability of the FAA to create a steaming pile out of a nice clean solution.
> > >
> > > I also remember that it was Bernald who introduced Urs to various parties in the US soaring community (myself included), with the explicit intent of bring Flarm into this country. In particular I was present at a number of informal discussions that took place around the '08 SSA convention that were set up by Bernald, which (again, if I remember correctly) led to the notion of PowerFlarm, the Flarm loaner/rental program, and other such things. It's funny how you've now decided that he is nothing more than a misguided salesman.
> > >
> > > Marc
> >
> > Marc
> >
> > And pushing UAT-Out futures for use in areas where airliners were a concern, like the Reno area, seemed to ignore the issue of lack of TCAS compatibility. And promised folks the hope of low-cost and easy to install UAT-Out devices when many should have been considering installing transpodners. it always just scared the hell out of me, to see this promoted as a goal at all, especially for areas like the Reno area, where TCAS II equipped traffic is such an issue.
> >
> > I sat through at least one PASCO seminar from Bernald and another given by you where some folks who attended took away that they won't be installing transponders but waiting for these UAT devices. I certainly remember one-post UAT presentation discussion with glider owners from the Reno area who were absolutely in love with this soon to be coming $500 portable box and totally opposed to istalling a $3,000 "power hungry" transponder. Many folks clearly took away far more than they shoudl have about the actual state of play of any of this stuff, and few if any really understood the limitations. Bernald has done may great things for he soaring community and soaring saftey, ultra impressive, but all that effort pushing UAT technology was just a bad idea. And you also have done a huge amount for soaring and soaring saftey, include your work in the Reno area, all fantastic stuff.
> >
> > And I think it was probalby you, indirectly through Benrald, that introduced me to Urs. Maybe after a seminar I had given on transponders, ADS-B and FLARM, ... partially with the goal of discouraging folks trying to import and use overseas-FLARM units, which was a bit of an underground idea going around at the time (including a few physical units kicking around). I've been happy to help the Flarm guys on some stuff when asked, but have done far far less there than many others in the USA who wanted to see this technology available for the Soaring Community.
> >
> > After that UAT promotion that was happening in the PASCO seminars I started giving presentations about glider batteries etc. if folks were worried about battery issues with transponders I certainly wanted them to know enough to have a cogent discussion. And I started to speak up in PASCO seminars etc. about the TCAS compatibility issue, I don't recall that was ever mentioned before, I could be wrong on that, but I never heard it raised. UAT-Out only adoption in the Reno area would gave been a very bad move, getting anything to happen with high tech/aviation/avionics is damn hard, but starting off trying to get something to happen that if it did succeed would be bad, is not a good idea.
> >
> > The final straw for me with all the UAT hype came the day I was flying out of Minden and the Hawker 800 collided with an ASG-29. I was at the other end of the Pinenut ranges when that happened. And one bizarre response to that was some folks talking up yet again the hope/need to UAT-Out devices. Jesus, TCAS-II equipped business jet, colliding with a glider with it's transponder turned off... what could people *not* get about that? Luckily most folks took that as a need to keep focusing on transponder use in that area.
> >
> > I doubt the establishment of PowerFLARM rental programs in the USA had any practical help from Bernald, what made that happen was Williams Soaring and generous donors actually stepping up and making that happen.
> >
> > I don't care if anybody use any particular traffic-awareness technology, but I hope that people at least evaluate what might help them. I'd hate for example to see say the glider exemption for transponders or ADS-B Out to be lost in future, that would be just a horrible waste for many gliders in many locations. In other locations where there are traffic concerns I hope owners/pilots/clubs/FBOs are looking at all the things that it is possible to do to reduce mid-air collision risks. And I care when others keep presenting misinformation/spurious arguments about might prevent some folks adopting what technology aids are practically available today.
>
> The ultimate goal that MITRE, Bernard, myself, and many other pilots had in promoting the UAT technology was to have a low cost, low power, ADS-B OUT solution that would be inexpensive enough so there would be no reason not to require universal equippage. With the introduction of UAVs into the system, with farmers, power companies, and others using these devices, unmanned drones are going to be everywhere. Even if you are in the middle of nowhere, you are going to have to make yourself electronically visible if you don't want to have some scary encounters down the road.
>
> As far as TCAS goes, this system was designed as the last line of defense if there was a complete breakdown in the ATC system's mission of separating IFR and GA traffic. Unfortunately, the FAA has permitted the controller community to use TCAS as a primary method of separating traffic. Under the current FARs, ATC only provides traffic separation between IFR traffic. Separation between IFR and VFR traffic is the pilots' responsibility, in both aircraft, using visual see and avoid eyeball technology.
>
> The Minden accident was a wakeup call on how well this works. The IFR / VFR visual separation rules date back to the 30s when aircraft where flying around at 100 knots with minimal traffic. The reality is that you can't really see someone in time if you have a closing rate of 300 - 400 knots. Making matters worse, is that most of the time jet pilots have their heads in the cockpits setting up for an approach, assuming that the ATC controllers will keep them out of harms way.
>
> The reality is that if you are lucky, and the workload permits, an ATC controller will give an IFR aircraft a traffic advisory for transponder or ADS-B equipped VFR traffic. It is not necessarily standard procedure for controllers to vector IFR traffic around conflicting GA traffic.
>
> This behavior was documented by an MIT Lincoln Lab study in 2005 monitoring the frequency of TCAS Resolution Advisories in the Boston area, and analyzing how pilots reacted to these events. They observed an average of 9 RAs per day within 60 miles of the Lincoln Labs receiver site. From the data, it appears that at least 30% of these events triggered abrupt evasive maneuvers within seconds of the RA, implying that the pilots had not visually recognized the conflicting traffic prior to the TCAS alarm. See: http://www.ll.mit.edu/publications/journal/pdf/vol16_no2/16_2_04Kuchar.pdf Pages 286-288.
>
> The bottom line is that TCAS RAs should not be happening at all. These events should be treated by the FAA with the same level of concern as runway incursions. Equipping all aircraft with transponders or ADS-B OUT systems alone will not solve the problem. What is needed is a fundamental change in the IFR / VFR separation rules to require ATC controllers to actively vector IFR traffic around conflicting VFR aircraft.
>
> Universal ADS-B OUT equipage would go a long way to providing a practical way to solve this problem. ADS-B IN equipped aircraft would be able to easily see potential conflicting traffic far in advance of any collision threat, when the danger could be completely avoided by a minor course correction.
>
> In the GA world today, these ADS-B IN systems are becoming quite popular and will help GA pilots proactively stay out of the way of conflicting airline traffic. Hopefully the FAA will recognize the safety value of this technology and relax their certification rules so that this technology is available at a reasonable cost, to permit existing jet aircraft operators to voluntarily retrofit their aircraft with this capability.

This is beyond comical. Airliners and other traffic have a last line defense of TCAS II that is known to be actually used in anger to avoid collisions.. You want to somehow ignore that and instead use alternative incompatible technology and rely on everything else being changed in a way that it will all now be perfect, and that last line of defense will somehow no longer be needed. Why not just forget UAT crap and do transponders with 1090ES that is compatible with SSR, PCAS, TCAD and TCAS? I know because some day maybe there will be low-cost UAT-Out devices, but congratulation if that ever happened, all you have is promoted is a dangerous technology choice with no TCAS etc. compatibility. This should have been shot in the head as a stupidly dangerous idea to start with.

Like bloody obvious, stupid idea, back when it was first pushed a decade or so ago, but why are you (and *only* you?) still going on about it? The FAA does not want it (they went off in the reverse direction, see below), the NTSB does not want it, the SSA told you to take a hike with your continuous pushing on UAT, ... but you are still going on about this.

If anything happens in future to lower surveillance equipment costs in gliders and similar aircraft it will likely be the decrease in costs as market forces shape products for 2020 compliance. Maybe you'll get something like a Mode-S transponder with 1090ES Out and a GPS in a glider for several $k. I'll be pleasantly surprised if it ever gets lower in a certified aircraft.

UAT-Out devices without also having a transponder are going to remain a very bad idea where fast jets/airliners are the main concern, and maybe for GA environments as well, and certainly where many other glider are equipped with PowerFLARM.

There might be a change driven by the LPSE/TABS direction that the FAA has adopted as TSO-C199, and that follows from many years of work on LPSE in Europe and elsewhere. And it will be all Mode-S and 1090ES based, no UAT crap allowed. TSO-C199 is yet another nail in the coffin for low-power UAT crap.. And you'd have to dig that coffin out of the grave to hammer that nail in, then you'd want to bury it again quickly before the stink of the corpse got to you. TSO-C199 very sensibly requires Mode S for compatibility TCAS (if you listen carefully you can hear the hand of the NTSB waving their big stick... and the Minden ASG-29/Hawker mid-air collision was directly a factor here), and being on Mode-S/1090ES provide a global market for technology providers (sensible since Europe drove lots of the earlier low-power Mode S work). Who knows if anything will happen here to lower glider transponder/1090ES Out costs in the USA, but I expect whatever happens for at least mid-size UAVs to be heavily influenced by TSO-C199 and all it's Mode-S/1090ES UAT-crap free goodness.

[email protected]

April 9th 15, 06:36 AM

They say truth is the first casualty of any argument...

"Unfortunately, the FAA has permitted the controller community to use TCAS as a primary method of separating traffic"

Traffic separation based on TCAS data is not permitted. Ever. Any pilot that reports "I've got them on TCAS" may as well be reading out the specials on the breakfast menu for all the operational significance that gives. Separation standards may only be reduced upon VISUAL sighting.

"it appears that at least 30% of these events triggered abrupt evasive maneuvers within seconds of the RA, implying that the pilots had not visually recognized the conflicting traffic prior to the TCAS alarm"

In a controlled environment, deviation from an ATC clearance is not permitted UNTILL there's an RA. You can only attempt self-separation OCTA. Of course, at the TA level you'll be trying to visually sight the traffic, informing ATC of the impending conflict and preparing to disconnect and fly the RA.. RA's are by their very nature more "abrupt" than normal ops but there's no reason to 'go ballastic Mav', something the industry is trying to address in recurrent training. Thus, abrupt manoeuvrring shouldn't be seen as defacto proof of the traffic not being sighted previously.

CJ

Mike Schumann[_2_]

April 9th 15, 06:53 AM

On Thursday, April 9, 2015 at 1:36:47 AM UTC-4, wrote:
> They say truth is the first casualty of any argument...
>
> "Unfortunately, the FAA has permitted the controller community to use TCAS as a primary method of separating traffic"
>
> Traffic separation based on TCAS data is not permitted. Ever. Any pilot that reports "I've got them on TCAS" may as well be reading out the specials on the breakfast menu for all the operational significance that gives. Separation standards may only be reduced upon VISUAL sighting.
>
> "it appears that at least 30% of these events triggered abrupt evasive maneuvers within seconds of the RA, implying that the pilots had not visually recognized the conflicting traffic prior to the TCAS alarm"
>
> In a controlled environment, deviation from an ATC clearance is not permitted UNTILL there's an RA. You can only attempt self-separation OCTA. Of course, at the TA level you'll be trying to visually sight the traffic, informing ATC of the impending conflict and preparing to disconnect and fly the RA. RA's are by their very nature more "abrupt" than normal ops but there's no reason to 'go ballastic Mav', something the industry is trying to address in recurrent training. Thus, abrupt manoeuvrring shouldn't be seen as defacto proof of the traffic not being sighted previously.
>
> CJ

I think you have a fundamental and dangerous misunderstanding of the FARs. Deviation from an ATC clearance is not only permitted, but required, if this is necessary for the safe operation of the aircraft. You don't need a TCAS RA in order to deviate. What you are seeing may be a glider that is not transponder equipped, so you will never get an RA. If you delay deviating from your clearance until you get the OK from ATC, you might all be dead.

Mike Schumann[_2_]

April 9th 15, 07:12 AM

On Thursday, April 9, 2015 at 1:00:58 AM UTC-4, Darryl Ramm wrote:
> On Wednesday, April 8, 2015 at 8:55:54 PM UTC-7, Mike Schumann wrote:
> > On Wednesday, April 8, 2015 at 7:11:20 PM UTC-4, Darryl Ramm wrote:
> > > On Wednesday, April 8, 2015 at 2:39:23 PM UTC-7, wrote:
> > > > On Wednesday, April 8, 2015 at 11:56:24 AM UTC-7, Darryl Ramm wrote:
> > > > > What I said was all the Mitre salesmanship and pro UAT-hype from folks like
> > > > > Bernald and you have not resulted in anything at all of use/benefit to the
> > > > > soaring community. Is that clear enough? And yes I know, the reasons why
> > > > > that is will be entirely somebody else's fault...
> > > >
> > > > Darryl, there was a lot of interesting discussion going on in ancient times (you know, before PowerFlarm, 8 or 9 years ago). As I remember it, Bernald was pushing UAT back then because there was a lot of concern about the possibility of glider vs. airliner collisions, and at the time, UAT seemed like it was going to be a good way of getting gliders, ultralights, balloons, etc., integrated into the air traffic system at low cost and with minimal power consumption. The icing on the cake was the Mitre UAT ADS-B out prototypes, that were basically built using $100 or so worth of cellphone chipsets and COTS GPS modules, and could run all day on a few AA cells. I know Mike was involved in the successful testing of these units in gliders and powered aircraft in the Virginia area (if I remember correctly). This was a promising technology with a lot of support even from groups within the FAA, with the end goal being pervasive use of UAT-based ADS-B technology in UAVs, general aviation, and gliders. The general understanding at the time was that these units would eliminate the need for transponders for general aviation. But, one should never underestimate the capability of the FAA to create a steaming pile out of a nice clean solution.
> > > >
> > > > I also remember that it was Bernald who introduced Urs to various parties in the US soaring community (myself included), with the explicit intent of bring Flarm into this country. In particular I was present at a number of informal discussions that took place around the '08 SSA convention that were set up by Bernald, which (again, if I remember correctly) led to the notion of PowerFlarm, the Flarm loaner/rental program, and other such things. It's funny how you've now decided that he is nothing more than a misguided salesman.
> > > >
> > > > Marc
> > >
> > > Marc
> > >
> > > And pushing UAT-Out futures for use in areas where airliners were a concern, like the Reno area, seemed to ignore the issue of lack of TCAS compatibility. And promised folks the hope of low-cost and easy to install UAT-Out devices when many should have been considering installing transpodners. it always just scared the hell out of me, to see this promoted as a goal at all, especially for areas like the Reno area, where TCAS II equipped traffic is such an issue.
> > >
> > > I sat through at least one PASCO seminar from Bernald and another given by you where some folks who attended took away that they won't be installing transponders but waiting for these UAT devices. I certainly remember one-post UAT presentation discussion with glider owners from the Reno area who were absolutely in love with this soon to be coming $500 portable box and totally opposed to istalling a $3,000 "power hungry" transponder. Many folks clearly took away far more than they shoudl have about the actual state of play of any of this stuff, and few if any really understood the limitations. Bernald has done may great things for he soaring community and soaring saftey, ultra impressive, but all that effort pushing UAT technology was just a bad idea. And you also have done a huge amount for soaring and soaring saftey, include your work in the Reno area, all fantastic stuff.
> > >
> > > And I think it was probalby you, indirectly through Benrald, that introduced me to Urs. Maybe after a seminar I had given on transponders, ADS-B and FLARM, ... partially with the goal of discouraging folks trying to import and use overseas-FLARM units, which was a bit of an underground idea going around at the time (including a few physical units kicking around). I've been happy to help the Flarm guys on some stuff when asked, but have done far far less there than many others in the USA who wanted to see this technology available for the Soaring Community.
> > >
> > > After that UAT promotion that was happening in the PASCO seminars I started giving presentations about glider batteries etc. if folks were worried about battery issues with transponders I certainly wanted them to know enough to have a cogent discussion. And I started to speak up in PASCO seminars etc. about the TCAS compatibility issue, I don't recall that was ever mentioned before, I could be wrong on that, but I never heard it raised. UAT-Out only adoption in the Reno area would gave been a very bad move, getting anything to happen with high tech/aviation/avionics is damn hard, but starting off trying to get something to happen that if it did succeed would be bad, is not a good idea.
> > >
> > > The final straw for me with all the UAT hype came the day I was flying out of Minden and the Hawker 800 collided with an ASG-29. I was at the other end of the Pinenut ranges when that happened. And one bizarre response to that was some folks talking up yet again the hope/need to UAT-Out devices. Jesus, TCAS-II equipped business jet, colliding with a glider with it's transponder turned off... what could people *not* get about that? Luckily most folks took that as a need to keep focusing on transponder use in that area.
> > >
> > > I doubt the establishment of PowerFLARM rental programs in the USA had any practical help from Bernald, what made that happen was Williams Soaring and generous donors actually stepping up and making that happen.
> > >
> > > I don't care if anybody use any particular traffic-awareness technology, but I hope that people at least evaluate what might help them. I'd hate for example to see say the glider exemption for transponders or ADS-B Out to be lost in future, that would be just a horrible waste for many gliders in many locations. In other locations where there are traffic concerns I hope owners/pilots/clubs/FBOs are looking at all the things that it is possible to do to reduce mid-air collision risks. And I care when others keep presenting misinformation/spurious arguments about might prevent some folks adopting what technology aids are practically available today.
> >
> > The ultimate goal that MITRE, Bernard, myself, and many other pilots had in promoting the UAT technology was to have a low cost, low power, ADS-B OUT solution that would be inexpensive enough so there would be no reason not to require universal equippage. With the introduction of UAVs into the system, with farmers, power companies, and others using these devices, unmanned drones are going to be everywhere. Even if you are in the middle of nowhere, you are going to have to make yourself electronically visible if you don't want to have some scary encounters down the road.
> >
> > As far as TCAS goes, this system was designed as the last line of defense if there was a complete breakdown in the ATC system's mission of separating IFR and GA traffic. Unfortunately, the FAA has permitted the controller community to use TCAS as a primary method of separating traffic. Under the current FARs, ATC only provides traffic separation between IFR traffic. Separation between IFR and VFR traffic is the pilots' responsibility, in both aircraft, using visual see and avoid eyeball technology.
> >
> > The Minden accident was a wakeup call on how well this works. The IFR / VFR visual separation rules date back to the 30s when aircraft where flying around at 100 knots with minimal traffic. The reality is that you can't really see someone in time if you have a closing rate of 300 - 400 knots. Making matters worse, is that most of the time jet pilots have their heads in the cockpits setting up for an approach, assuming that the ATC controllers will keep them out of harms way.
> >
> > The reality is that if you are lucky, and the workload permits, an ATC controller will give an IFR aircraft a traffic advisory for transponder or ADS-B equipped VFR traffic. It is not necessarily standard procedure for controllers to vector IFR traffic around conflicting GA traffic.
> >
> > This behavior was documented by an MIT Lincoln Lab study in 2005 monitoring the frequency of TCAS Resolution Advisories in the Boston area, and analyzing how pilots reacted to these events. They observed an average of 9 RAs per day within 60 miles of the Lincoln Labs receiver site. From the data, it appears that at least 30% of these events triggered abrupt evasive maneuvers within seconds of the RA, implying that the pilots had not visually recognized the conflicting traffic prior to the TCAS alarm. See: http://www.ll.mit.edu/publications/journal/pdf/vol16_no2/16_2_04Kuchar.pdf Pages 286-288.
> >
> > The bottom line is that TCAS RAs should not be happening at all. These events should be treated by the FAA with the same level of concern as runway incursions. Equipping all aircraft with transponders or ADS-B OUT systems alone will not solve the problem. What is needed is a fundamental change in the IFR / VFR separation rules to require ATC controllers to actively vector IFR traffic around conflicting VFR aircraft.
> >
> > Universal ADS-B OUT equipage would go a long way to providing a practical way to solve this problem. ADS-B IN equipped aircraft would be able to easily see potential conflicting traffic far in advance of any collision threat, when the danger could be completely avoided by a minor course correction.
> >
> > In the GA world today, these ADS-B IN systems are becoming quite popular and will help GA pilots proactively stay out of the way of conflicting airline traffic. Hopefully the FAA will recognize the safety value of this technology and relax their certification rules so that this technology is available at a reasonable cost, to permit existing jet aircraft operators to voluntarily retrofit their aircraft with this capability.
>
> This is beyond comical. Airliners and other traffic have a last line defense of TCAS II that is known to be actually used in anger to avoid collisions. You want to somehow ignore that and instead use alternative incompatible technology and rely on everything else being changed in a way that it will all now be perfect, and that last line of defense will somehow no longer be needed. Why not just forget UAT crap and do transponders with 1090ES that is compatible with SSR, PCAS, TCAD and TCAS? I know because some day maybe there will be low-cost UAT-Out devices, but congratulation if that ever happened, all you have is promoted is a dangerous technology choice with no TCAS etc. compatibility. This should have been shot in the head as a stupidly dangerous idea to start with.
>
> Like bloody obvious, stupid idea, back when it was first pushed a decade or so ago, but why are you (and *only* you?) still going on about it? The FAA does not want it (they went off in the reverse direction, see below), the NTSB does not want it, the SSA told you to take a hike with your continuous pushing on UAT, ... but you are still going on about this.
>
> If anything happens in future to lower surveillance equipment costs in gliders and similar aircraft it will likely be the decrease in costs as market forces shape products for 2020 compliance. Maybe you'll get something like a Mode-S transponder with 1090ES Out and a GPS in a glider for several $k.. I'll be pleasantly surprised if it ever gets lower in a certified aircraft.

Darryl Ramm

April 9th 15, 07:22 AM

On Wednesday, April 8, 2015 at 8:55:54 PM UTC-7, Mike Schumann wrote:
Unfortunately, the FAA has permitted the controller community to use TCAS as a primary method of separating traffic.

Oh Dear God no. Oh well anybody who has spent any time with a TCAS system or in an ATC facility knows you have no clue what you are talking about. TCAS is *not* ever a primary means of separation. Not intended to be, not allowed to be. It is an emergency saftey net to complement visual and ATC separation. And how or why would a controller "use TCAS for separation". If a TCAS RA happens it ruins the day for all the aircrew involved and for the controller, paperwork and maybe new pants required..

Darryl Ramm

April 9th 15, 07:34 AM

Here is an SFO Tower Controller having his day very ruined by a TCAS II RA. Maybe he was confused and trying to use it as a primary means of separation? https://www.youtube.com/watch?v=COVQoQojQ38

Darryl Ramm

April 9th 15, 08:04 AM

And while on YouTube if anybody want to see what a TCAS II RA (resolution advisory) looks like from the other side have a look at this. https://www.youtube.com/watch?v=OrYqIU0NxHQ

That happens with any aircraft with TCAS II against any threat aircraft with a Mode C or Mode S transponder. That works at any location or altitude (integration with TAWS prevents the TCAS II instructing the pilot to fly into the ground). All completely independent of ATC involvement or SSR radar coverage. TCAS does not require any ADS-B-Out anything in the threat aircraft, just a transponder. If the threat aircraft has UAT-Out only, the airliner would fly right through then with no RA. TCAS II is basically carried by all airliners, many business jets, lots of military transport aircraft. Simpler TCAS I and TCAD systems that work similarly and can provide a TA (traffic advisory) but not an RA are reaching down into to high-end piston-single GA market. For example Garmin has a really nice GTS-800 series product that provides TCAS I as well as ADS-B In capability. Heck Garmin even makes full TCAS-II 8000 series products aimed at the turboprop/light jet market (~$20k for the box, a impressively low cost for TCAS II, install costs will hurt :-().

Darryl Ramm

April 9th 15, 08:16 AM

On Wednesday, April 8, 2015 at 11:34:50 PM UTC-7, Darryl Ramm wrote:
> Here is an SFO Tower Controller having his day very ruined by a TCAS II RA. Maybe he was confused and trying to use it as a primary means of separation? https://www.youtube.com/watch?v=COVQoQojQ38

And here is some of the ass hurt from that controller mistake that led to the TCAS RA, http://www.ntsb.gov/_layouts/ntsb.aviation/brief2.aspx?ev_id=20100330X00627&ntsbno=OPS10IA020B&akey=2

Dave Nadler

April 9th 15, 12:45 PM

On Wednesday, April 8, 2015 at 5:39:23 PM UTC-4, wrote:
> I also remember that it was Bernald who introduced Urs to various
> parties in the US soaring community (myself included), with the explicit
> intent of bring Flarm into this country. In particular I was present
> at a number of informal discussions that took place around the '08 SSA
> convention that were set up by Bernald, which (again, if I remember
> correctly) led to the notion of PowerFlarm, the Flarm loaner/rental
> program, and other such things. It's funny how you've now decided
> that he is nothing more than a misguided salesman.

Apparently you are unaware that many of us in USA worked to bring
FLARM to USA for years before that, and knew the FLARM crew from when
they were still at university. What we faced was, as usual, stubborn
resistance in USA from those utterly unaware of what was going on the
rest of the world.

Bernald did NOT help with FLARM adoption, rather he opposed it.
Numerous times I sat with Bernald and explained to him why UAT was
not going to work for gliders until he understood, only to find
he seemed to have forgotten we even had the conversation days later.

The "PowerFLARM notion" was from market demand for a FLARM for
powered aircraft, ideally with PCAS and better FLARM range.
Because legacy FLARM are not compatible with USA's FCC regulations,
and they had promised me to bring FLARM to USA, FLARM agreed to
introduce it in USA and make it FCC compliant, and I helped create
it. This all in spite of continued parochial resistance in USA
and the USA-specific UAT idiocy.

Really now.

John Carlyle

April 9th 15, 02:40 PM

Regarding Mike Schumann's comment predicting UAVs will be equipped with UAT, at least one company offering new equipment aimed at UAVs doesn't agree. Check out the new offerings from Sagetech here: http://www.sagetechcorp.com/unmanned-solutions/#.VSZ9SPDNrkc

As you can see, they offer Mode S, Mode S with ADS-B Out and Mode S with ADS-B Out and GPS, but there is no mention of UAT. Mike, you may want to call them and explain what a huge mistake they're making.

-John, Q3

On Thursday, April 9, 2015 at 2:12:08 AM UTC-4, Mike Schumann wrote:
> What's with the insulting hysteria in your posts?
>
> I am not recommending that anyone buy UAT based ADS-B OUT transmitters. The way the market is headed, the smartest choice for glider pilots may very well be going the 1090ES route.
>
> What I am pointing out is that UAT is part of the system. There will be aircraft and UAVs out there that are UAT ADS-B OUT equipped and may not have conventional transponders. How many is anyone's guess at this time. Neither you nor I have any significant influence on what other pilots buy. This will be determined by market forces and the individual preferences of the various A/C owners.
>
> The only thing that I am saying is that, if you are buying any avionics that includes ADS-B IN, make sure it supports both UAT and 1090ES. This can be accomplished by having a dual frequency receiver, or by correctly handling TIS-B and ADS-B R transmissions received from ADS-B ground stations.
>
> If you are thinking about buying POWERFLARM, you need to move forward with your eyes wide open and understand that as currently implemented, you will not be seeing UAT ADS-B OUT equipped aircraft. You will also not be getting weather and notam data that is a standard feature of competitive low cost ADS-B IN products. If you want to spend money on a half baked solution like this, that's totally your call.

Andy Blackburn[_3_]

April 9th 15, 03:42 PM

On Thursday, April 9, 2015 at 6:40:27 AM UTC-7, John Carlyle wrote:
> Regarding Mike Schumann's comment predicting UAVs will be equipped with UAT, at least one company offering new equipment aimed at UAVs doesn't agree.. Check out the new offerings from Sagetech here: http://www.sagetechcorp.com/unmanned-solutions/#.VSZ9SPDNrkc
>
> As you can see, they offer Mode S, Mode S with ADS-B Out and Mode S with ADS-B Out and GPS, but there is no mention of UAT. Mike, you may want to call them and explain what a huge mistake they're making.
>
> -John, Q3
>

Also it would be good to be more clear about terminology. UAV, while a generic term, is often used to describe military remotely piloted aircraft and/or autonomous vehicles. Typically you'll find these in the US in MOAs or Restricted areas at a wide variety of speeds and altitudes under reasonably controlled conditions. At least one vendor is using 1090ES on these aircraft.. The main purpose is to make UAVs visible to ATC radar so 1090ES is likely a better choice since it will be new installations where 1090ES gives transponder as well as GP position capability. I seriously doubt that UAT would be viewed as suitable.

Personal drones are increasingly numerous and fly today all over the US, generally below 400' if they're legal - occasionally above. They are probably of the greatest risk to gliders if they fly near glider airports. At $300 up to several thousand $, cost, size and power consumption are critical considerations for any traffic warning technology. It's my understanding that Flarm is in discussions with manufacturers of these.

As to commercial drones delivering packages for Amazon, I'd not worry too much about that yet. If and when it comes it will likely be of greater risk to your cat than to your glider. I'm not sure what technology Amazon wants to use, though cost, size and weight will likely be concerns. I suspect if/when autonomous flight is allowed it won't be allowed near airports or above 400'.

Andy

[email protected]

April 9th 15, 04:05 PM

"I think you have a fundamental and dangerous misunderstanding...."

You're having a laugh, right? Taking the Mickey? Pulling my leg?

You can't possibly be standing on the 'PIC rule' to justify your position.

My comment was, is and will remain to be, in relation to TCAS as you erroneously claimed its use for traffic separation. TA's are to to be responded to as it can create a 'Lord of the Flies' effect. Like 1 driver swerving across 3 lanes of a packed LA freeway. Chaos. When you have multiple aircraft at minimum separation with hundreds of people on board each one, you don't want one idiot going rogue and creating more conflicts than he solves.

If it was a non-transponder equipped glider you wouldn't get a TA to begin with so the point is moot.

[email protected]

April 9th 15, 05:42 PM

Beeeeeep! Sh--t Glance down Red dot 12:00 O'clock same altitude. Turn sort it out on the radio with the other pilot. Investment in FLARM fully amortized.
7D

Darryl Ramm

April 9th 15, 06:04 PM

Not only has Sagetech already got impressive Mode-C/mode-S/1090ES out hardware that scales down to relatively small drones, but again to harp on TSO-C199... That provides a model for potentially getting some of this stuff in manned aircraft. That new TSO provides a path for manufacturers to build low-power Mode-S/1090ES devices that use non-TSO GPS sources, and not just "meets requirements of" GPS sources but stuff actually based on more consumer GPS technology. We could eventually see that in certified gliders and to interact fully with TCAS the 1090ES receivers and the ADS-B ground infrastructure. But I suspect if anything that TSO will actually morph into use in the UAV market. Which is great for TCAS and for glider pilots with direct compatibility with PowerFLARM 1090ES In. So I don't want to hype futures, and nothing at all may come from this that affect gliders....it is more just an interesting sign that non-Transponder UAT-Out only solutions are dead and buried. If you fly near airliners and fast jets, and maybe lots of GA traffic please do not put off considering installing a transponder because of future technology speculation.

Oh yes and FLARM was a direct inspiration for the FAA developing TSO-C199.... :-)

Darryl Ramm

April 9th 15, 06:04 PM

kirk.stant

April 9th 15, 07:02 PM

On Wednesday, April 8, 2015 at 7:27:06 PM UTC-5, Bob Pasker wrote:

> did the transponder in that plane display pressure altitude, like my KTX-76? if so, did it show the wrong altitude? the right altitude? and when you realized what happened, did you call approach or center and ask for an altimeter readout?

Bob, it's an older Mode A/C transponder that doesn't show the pressure altitude it is transmitting. After we cycled it off and on a couple of times, my PCAS started to show the correct altitude, so we assumed that we had "fixed" whatever the problem was. Owners of the RV-6 are now shopping for a new xponder, by the way, and have already bought a PCAS device very similar to my out-of-production MRX.

Kirk
66

Darryl Ramm

April 9th 15, 09:03 PM

On Wednesday, March 25, 2015 at 8:03:03 PM UTC-7, Bill T wrote:
> Darryl, I've been looking and for most standard certificated aircraft, not experimental, it takes STC to install ADS-B equipment. A couple of STCs I have found do not list the Piper Pawnee, PA-25. Any Pawnee I have seen is registered under Restricted category. Any ideas?
> BillT

Bill

Just as a heads up, here is another Mode-S/1090ES Out transponder coming with internal GPS. http://ipadpilotnews.com/2015/04/new-stratus-esg-ads-b-transponder and https://www.appareo.com/aviation/ads-b-out

Details are very sparse, but it is apparently intended for install in certified aircraft, at a ~$3,500 unit price.

I am a bit skeptical about the button only UI, especially for use in turbulence with the ON/OFF/ALT/VFR/etc buttons so close to each other. Anyhow hopefully part of a trend of better product availability for those tow planes that need to meet the 2020 ADS-B carriage mandate.

(and for others I would not assume this is at all suitable for install in gliders, too large, and it is likely has too high a power consumption).

Darryl

Andy Blackburn[_3_]

April 9th 15, 09:10 PM

On Thursday, April 9, 2015 at 1:03:26 PM UTC-7, Darryl Ramm wrote:
> On Wednesday, March 25, 2015 at 8:03:03 PM UTC-7, Bill T wrote:
> > Darryl, I've been looking and for most standard certificated aircraft, not experimental, it takes STC to install ADS-B equipment. A couple of STCs I have found do not list the Piper Pawnee, PA-25. Any Pawnee I have seen is registered under Restricted category. Any ideas?
> > BillT
>
> Bill
>
> Just as a heads up, here is another Mode-S/1090ES Out transponder coming with internal GPS. http://ipadpilotnews.com/2015/04/new-stratus-esg-ads-b-transponder and https://www.appareo.com/aviation/ads-b-out
>

I thought the following excerpt from the press release was interesting, and consistent with the view that installation cost and complexity are significant factors that might advantage 1090ES over UAT even for aircraft that aren't required to carry 1090ES by rule:

"Appareo also recognized that the cost and complexity to install many of the existing ADS-B Out transponders is exceedingly high, so they focused on developing a system that would be simple for avionics shop to install. Stratus ESG connects directly to the existing belly-mounted transponder antenna and also includes a WAAS GPS antenna. For typical single-engine piston aircraft, Stratus ESG will require approximately half the installation time as compared to a remote-mounted 978 Mhz UAT ADS-B Out system."

Bill T

April 10th 15, 04:53 AM

Thanks!
That is a promising option.
As for the buttons so close, check out the Garmin transponders with all the buttons in a circle.

BillT

Bob Pasker

April 11th 15, 07:56 PM

On Thursday, April 9, 2015 at 2:02:28 PM UTC-4, kirk.stant wrote:
After we cycled it off and on a couple of times, my PCAS started to show the correct altitude, so we assumed that we had "fixed" whatever the problem was.

i'm guessing ATC in that sector was surprised to see you climb 6,000ft in altitude, and wondering about that piece of tin that was now heading away from you at your altitude.

Andrew Ainslie

April 14th 15, 06:20 PM

....Boy, for a supposedly redundant posting that was utterly covered by prior posts, this thread sure grew legs :)

[email protected]

May 1st 15, 12:14 AM

AeroSports Update: An ADS-B Choice For Experimental Aircraft
The NavWorx ADS600-EXP Is An ADS-B Solution That Is Tailored Towards The Experimental Aircraft Market
NavWorx, Inc. claims they were the first to announce a truly affordable solution for experimental and LSA aircraft owners with the release of its ADS600-EXP. This announcement came on the heels of the FAA's ADS-B rule interpretation in February that devices must meet the "performance requirements" of TSO-C154c, but do not have to be TSO'ed.
NavWorx says their ADS600-EXP is a complete ADS-B solution for experimental and LSA aircraft. The ADS600-EXP communicates with a wide variety of display systems via Wi-Fi and RS232. For a limited time, NavWorx is offering the ADS600-EXP at a price of $869.00.
Design of the NavWorx ADS600-EXP is based on the company's ADS600-B, a FAA TSO/STC certified unit. Both comply with the ADS-B mandates of TSO-C154c and TSO-C145c. The ADS600-EXP is a Universal Access Transceiver (UAT) and provides full ADS-B Out and In operations.
All ADS600 UAT devices come with NavWorx' patent-pending TransMonSPETM. This device installs on the aircraft's existing transponder coax cable to provide for single point of entry of the squawk code, ident, and Mode A/C. TransMonSPETM also provides pressure encoder data to the ADS600-series. It meets the FAA's requirement to have a single point of entry for the squawk code, and satisfies the specification that requires both the transponder and ADS-B to use the same pressure encoder. TransMonSPETM is TSO certified and will interface with older transponders eliminating any need to replace the transponder or altitude encoder.
NavWorx ADS-B solutions are also available for type certificated aircraft offering solutions for operators with a variety of installation requirements.. The company also offers pre-built harnesses and coax cables.
http://www.aero-news.net/index.cfm?do=main.textpost&id=521755c8-d16c-4433-8019-2e656d396961
Reprinted with permission from Aero-News.net

Darryl Ramm

May 3rd 15, 02:58 AM

On Thursday, April 30, 2015 at 4:14:47 PM UTC-7, wrote:
> AeroSports Update: An ADS-B Choice For Experimental Aircraft
> The NavWorx ADS600-EXP Is An ADS-B Solution That Is Tailored Towards The Experimental Aircraft Market
> NavWorx, Inc. claims they were the first to announce a truly affordable solution for experimental and LSA aircraft owners with the release of its ADS600-EXP. This announcement came on the heels of the FAA's ADS-B rule interpretation in February that devices must meet the "performance requirements" of TSO-C154c, but do not have to be TSO'ed.
> NavWorx says their ADS600-EXP is a complete ADS-B solution for experimental and LSA aircraft. The ADS600-EXP communicates with a wide variety of display systems via Wi-Fi and RS232. For a limited time, NavWorx is offering the ADS600-EXP at a price of $869.00.
> Design of the NavWorx ADS600-EXP is based on the company's ADS600-B, a FAA TSO/STC certified unit. Both comply with the ADS-B mandates of TSO-C154c and TSO-C145c. The ADS600-EXP is a Universal Access Transceiver (UAT) and provides full ADS-B Out and In operations.
> All ADS600 UAT devices come with NavWorx' patent-pending TransMonSPETM. This device installs on the aircraft's existing transponder coax cable to provide for single point of entry of the squawk code, ident, and Mode A/C. TransMonSPETM also provides pressure encoder data to the ADS600-series. It meets the FAA's requirement to have a single point of entry for the squawk code, and satisfies the specification that requires both the transponder and ADS-B to use the same pressure encoder. TransMonSPETM is TSO certified and will interface with older transponders eliminating any need to replace the transponder or altitude encoder.
> NavWorx ADS-B solutions are also available for type certificated aircraft offering solutions for operators with a variety of installation requirements. The company also offers pre-built harnesses and coax cables.
> http://www.aero-news.net/index.cfm?do=main.textpost&id=521755c8-d16c-4433-8019-2e656d396961
> Reprinted with permission from Aero-News.net

A nice price point (for experimental aircraft), but a UAT only (not 1090ES) Out/In only device. The big issue there is it won't make that aircraft visible to a PowerFLARM via ADS-B... which is why towplane owners who need to meet the ADS-B Out 2020 carriage mandate will hopefully wait for the market to improve and do ADS-B out with 1090ES.

[email protected]

May 3rd 15, 05:26 AM

Dual Receiver option 1090ES RECEIVER ADD-IN for $89.

http://www.navworx.com/navworx_store/Experimental_Aircraft_Transceivers/ADS600_EXP.html

Darryl Ramm

May 3rd 15, 07:36 AM

On Saturday, May 2, 2015 at 9:26:36 PM UTC-7, wrote:
> Dual Receiver option 1090ES RECEIVER ADD-IN for $89.
>
> http://www.navworx.com/navworx_store/Experimental_Aircraft_Transceivers/ADS600_EXP.html

That still won't make any aircraft equipped with this visible to a PowerFLARM.

Mike Schumann[_2_]

May 3rd 15, 02:19 PM

On Saturday, May 2, 2015 at 9:59:01 PM UTC-4, Darryl Ramm wrote:
> On Thursday, April 30, 2015 at 4:14:47 PM UTC-7, wrote:
> > AeroSports Update: An ADS-B Choice For Experimental Aircraft
> > The NavWorx ADS600-EXP Is An ADS-B Solution That Is Tailored Towards The Experimental Aircraft Market
> > NavWorx, Inc. claims they were the first to announce a truly affordable solution for experimental and LSA aircraft owners with the release of its ADS600-EXP. This announcement came on the heels of the FAA's ADS-B rule interpretation in February that devices must meet the "performance requirements" of TSO-C154c, but do not have to be TSO'ed.
> > NavWorx says their ADS600-EXP is a complete ADS-B solution for experimental and LSA aircraft. The ADS600-EXP communicates with a wide variety of display systems via Wi-Fi and RS232. For a limited time, NavWorx is offering the ADS600-EXP at a price of $869.00.
> > Design of the NavWorx ADS600-EXP is based on the company's ADS600-B, a FAA TSO/STC certified unit. Both comply with the ADS-B mandates of TSO-C154c and TSO-C145c. The ADS600-EXP is a Universal Access Transceiver (UAT) and provides full ADS-B Out and In operations.
> > All ADS600 UAT devices come with NavWorx' patent-pending TransMonSPETM. This device installs on the aircraft's existing transponder coax cable to provide for single point of entry of the squawk code, ident, and Mode A/C. TransMonSPETM also provides pressure encoder data to the ADS600-series. It meets the FAA's requirement to have a single point of entry for the squawk code, and satisfies the specification that requires both the transponder and ADS-B to use the same pressure encoder. TransMonSPETM is TSO certified and will interface with older transponders eliminating any need to replace the transponder or altitude encoder.
> > NavWorx ADS-B solutions are also available for type certificated aircraft offering solutions for operators with a variety of installation requirements. The company also offers pre-built harnesses and coax cables.
> > http://www.aero-news.net/index.cfm?do=main.textpost&id=521755c8-d16c-4433-8019-2e656d396961
> > Reprinted with permission from Aero-News.net
>
> A nice price point (for experimental aircraft), but a UAT only (not 1090ES) Out/In only device. The big issue there is it won't make that aircraft visible to a PowerFLARM via ADS-B... which is why towplane owners who need to meet the ADS-B Out 2020 carriage mandate will hopefully wait for the market to improve and do ADS-B out with 1090ES.

At this price point, there are going to be a lot of GA aircraft buying this, or similar UAT products, to meet the 2020 mandate. That's reality folks. If you buy PowerFlarm, you're not going to see these aircraft. Do you really want to invest in this kind of half baked technology?

kirk.stant

May 4th 15, 04:08 AM

On Sunday, May 3, 2015 at 8:19:53 AM UTC-5, Mike Schumann wrote:

> At this price point, there are going to be a lot of GA aircraft buying this, or similar UAT products, to meet the 2020 mandate. That's reality folks. If you buy PowerFlarm, you're not going to see these aircraft. Do you really want to invest in this kind of half baked technology?

Oh bull****. You still need a Mode A/C or Mode S transponder to get full use of airspace, and to get ANY protection from TCAS-equipped jet. NO-ONE will be UAT only ADS-B out, IMO. Why would they?

And guess what, with my PowerFLARM, RIGHT NOW, I get excellent warning of ALL Mode A/C/S and 1090ES ADS-B traffic in my vicinity, as well as really good glider anti collision warnings.

Mike, your bias is noted. But at least try to be honest with the facts.

Kirk
66

Mike Schumann[_2_]

May 4th 15, 08:18 AM

On Sunday, May 3, 2015 at 11:08:28 PM UTC-4, kirk.stant wrote:
> On Sunday, May 3, 2015 at 8:19:53 AM UTC-5, Mike Schumann wrote:
>
> > At this price point, there are going to be a lot of GA aircraft buying this, or similar UAT products, to meet the 2020 mandate. That's reality folks. If you buy PowerFlarm, you're not going to see these aircraft. Do you really want to invest in this kind of half baked technology?
>
> Oh bull****. You still need a Mode A/C or Mode S transponder to get full use of airspace, and to get ANY protection from TCAS-equipped jet. NO-ONE will be UAT only ADS-B out, IMO. Why would they?
>
> And guess what, with my PowerFLARM, RIGHT NOW, I get excellent warning of ALL Mode A/C/S and 1090ES ADS-B traffic in my vicinity, as well as really good glider anti collision warnings.
>
> Mike, your bias is noted. But at least try to be honest with the facts.
>
> Kirk
> 66

Let's all be honest with the facts. Saying that PowerFlarm gives you "excellent" warning for Mode C equipped aircraft is a stretch. What you are really getting is a warning that tells you the altitude of the potential threat aircraft, and a rough estimate of its distance, based on some crude assumptions from the received power level of the transponder signal. Other than that, you have absolutely no idea where this aircraft is.

If this A/C is UAT ADS-B OUT equipped, this is all you will see with your PowerFlarm system. With a properly designed ADS-B receiver (either dual frequency or one supporting TIS-B and ADS-R), you would see the exact position of this aircraft within ~50 ft. If you had a NavWorx or similar transceiver, and you were within range of an ADS-B ground station, using TIS-B, you would also see the location of every other transponder equipped aircraft that is visible to ATC, regardless of whether or not it was ADS-B OUT equipped.

PowerFLARM is the only ADS-B receiver being sold in the US that is not designed to properly handle the dual frequency UAT / 1099ES environment that is the reality in US airspace. This is a huge shortcoming in the product that raises a lot of questions about the competency of the design team that put this system together.

Vaughn

May 4th 15, 01:19 PM

On 5/4/2015 3:18 AM, Mike Schumann wrote:
> PowerFLARM is the only ADS-B receiver being sold in the US that is not designed to properly
> handle the dual frequency UAT / 1099ES environment that is the
reality in US airspace.

Like many things you continually repeat Mike, this simply isn't so!

You can buy many single frequency ADS-B receivers. Mine (made by Dual)
also lacks the PCAS feature that is built in to Powerflarm.

Why did I buy it? Mostly for the free FAA weather.

Vaughn

kirk.stant

May 4th 15, 03:48 PM

On Monday, May 4, 2015 at 2:18:47 AM UTC-5, Mike Schumann wrote:

> Let's all be honest with the facts. Saying that PowerFlarm gives you "excellent" warning for Mode C equipped aircraft is a stretch. What you are really getting is a warning that tells you the altitude of the potential threat aircraft, and a rough estimate of its distance, based on some crude assumptions from the received power level of the transponder signal. Other than that, you have absolutely no idea where this aircraft is.

Well let's see. My PF gives me the altitude difference (unless you are co-altitude, it's REALLY hard to have a mid-air) and whether the Mode C traffic is getting closer or not. That is plenty of information in the VFR environment we fly gliders in, considering our maneuverability and great visibility, to put all emphasis on visual scan and finding the approaching traffic.. Or do you not believe you can see other airplanes while flying VFR?

Meanwhile, do you fly with ANY of your magic UAT ADS-B hardware when you fly your (or your club's) glider? If so, I would love to know what you have installed.

Meanwhile, I'm also getting precise position of all the fast movers via the 1090ES part of PF, and really precise collision avoidance of other PF-equipped gliders.

I guess we'll see in a few years who is right - because if the majority of ADS-B out installations in the US end up using 1090ES out, or even dual band to take advantage of the free weather and traffic info (remember, traffic info is actually just a benefit of the ADS-B program, not the raison-d'etre!), then PF will have nailed it on the head.

> If this A/C is UAT ADS-B OUT equipped, this is all you will see with your PowerFlarm system. With a properly designed ADS-B receiver (either dual frequency or one supporting TIS-B and ADS-R), you would see the exact position of this aircraft within ~50 ft. If you had a NavWorx or similar transceiver, and you were within range of an ADS-B ground station, using TIS-B, you would also see the location of every other transponder equipped aircraft that is visible to ATC, regardless of whether or not it was ADS-B OUT equipped.

So, describe what ADS-B hardware, displays, software YOU would install in your glider, today. And the cost.

> PowerFLARM is the only ADS-B receiver being sold in the US that is not designed to properly handle the dual frequency UAT / 1099ES environment that is the reality in US airspace. This is a huge shortcoming in the product that raises a lot of questions about the competency of the design team that put this system together.

Wow, you really have an issue with the success of Flarm, don't you? I guess the fact that it has proven to be highly successful in the rest of the world, and is practically mandatory in Europe (France for sure), and that in those markets there is NO UAT ADS-B, and that the market for PF in the US is pretty much limited to the XC and racing community, must really **** you off. Hey, go ahead and load up you glider with your fancy UAT gizmos and give us a report on how it all works - an article in Soaring would be awesome!

Meanwhile, I'll stick to what I have, knowing that it works.

Cheers,

Kirk
66

kirk.stant

May 4th 15, 04:13 PM

On Sunday, May 3, 2015 at 1:36:32 AM UTC-5, Darryl Ramm wrote:

> > http://www.navworx.com/navworx_store/Experimental_Aircraft_Transceivers/ADS600_EXP.html
>
> That still won't make any aircraft equipped with this visible to a PowerFLARM.

No, but since you still have to have a Mode A/C/S transponder when you install the ADS600_EXP, that aircraft is ALREADY visible to a PowerFLARM.

You CANNOT have JUST an UAT-based ADS-B in/out system. It's either UAT-out/in WITH a Mode A/C/S transponder, OR 1090 ES ADS-B out, and UAT-in for the freebie weather and traffic, etc.

RTFM, guys!

Kirk
66

Mike Schumann[_2_]

May 4th 15, 10:50 PM

On Monday, May 4, 2015 at 8:19:52 AM UTC-4, Vaughn wrote:
> On 5/4/2015 3:18 AM, Mike Schumann wrote:
> > PowerFLARM is the only ADS-B receiver being sold in the US that is not designed to properly
> > handle the dual frequency UAT / 1099ES environment that is the
> reality in US airspace.
>
> Like many things you continually repeat Mike, this simply isn't so!
>
> You can buy many single frequency ADS-B receivers. Mine (made by Dual)
> also lacks the PCAS feature that is built in to Powerflarm.
>
> Why did I buy it? Mostly for the free FAA weather.
>
> Vaughn

The Dual XGPS170 ADS-B receiver is a properly designed unit that fully supports the US UAT/1090ES environment. It is a single frequency (UAT) receiver. However it supports TIS-B and ADS-R, so you will see all 1090ES ADS-B OUT and Mode C transponder equipped aircraft, if you are within range of an ADS-B ground station AND you are ADS-B OUT equipped (either 1090ES or UAT). Without being ADS-B OUT equipped, you may see TIS-B traffic if there is an ADS-B OUT equipped aircraft in your vicinity, but I wouldn't count on that..

If you installed ADS-B OUT in your glider, this unit would give you much better collision avoidance information identifying other transponder equipped aircraft than the PCAS function available in PowerFLARM or other PCAS type devices.

Just out of curiousity, what app are you running with this unit?

Mike Schumann[_2_]

May 4th 15, 11:02 PM

On Monday, May 4, 2015 at 11:13:55 AM UTC-4, kirk.stant wrote:
> On Sunday, May 3, 2015 at 1:36:32 AM UTC-5, Darryl Ramm wrote:
>
> > > http://www.navworx.com/navworx_store/Experimental_Aircraft_Transceivers/ADS600_EXP.html
> >
> > That still won't make any aircraft equipped with this visible to a PowerFLARM.
>
> No, but since you still have to have a Mode A/C/S transponder when you install the ADS600_EXP, that aircraft is ALREADY visible to a PowerFLARM.
>
> You CANNOT have JUST an UAT-based ADS-B in/out system. It's either UAT-out/in WITH a Mode A/C/S transponder, OR 1090 ES ADS-B out, and UAT-in for the freebie weather and traffic, etc.
>
> RTFM, guys!
>
> Kirk
> 66

You are totally mistaken that everyone who installs ADS-B OUT needs to have a Mode C or Mode S transponder. For starters, gliders are totally exempt from both the ADS-B OUT and transponder mandates. That also applies to all other aircraft that either do not have electrical systems, or operate outside of the Mode C veil and below 10,000 ft.

With the cost of ADS-B OUT UAT transceivers dropping below $1,000 it is totally conceivable that a significant number of glider pilots will buy these systems and not invest an extra $2K in a transponder. Some pilots may elect to invest in portable UAT transceivers that they can share in a club environment.

This will not make the glider visible to today's airliner TCAS systems, but it will make the glider visible on ATC radar. Hopefully ATC will have the common sense to vector any traffic around you. In addition, the UAT transceiver equipped glider will clearly see the big iron traffic and be able to stay out of the way.

kirk.stant

May 5th 15, 03:52 PM

On Monday, May 4, 2015 at 5:02:29 PM UTC-5, Mike Schumann wrote:

> You are totally mistaken that everyone who installs ADS-B OUT needs to have a Mode C or Mode S transponder. For starters, gliders are totally exempt from both the ADS-B OUT and transponder mandates. That also applies to all other aircraft that either do not have electrical systems, or operate outside of the Mode C veil and below 10,000 ft.

Oh get real, Mike. The subset of aircraft that are exempt from the transponder mandate that will bother to put anykind of ADS-B is pretty small. At best, there will be a relatively cheap battery-powered system developed that will fill that niche (ultralights, powered chutes - and maybe some training gliders/towplanes. But for the rest of the aviation world, the need to fly above 10,000 and in Class C/B airspace means transponders. And if you don't need to fly there, they won't bother with any ADS-B - heck, many club gliders in the US don't even have radios!

>
> With the cost of ADS-B OUT UAT transceivers dropping below $1,000 it is totally conceivable that a significant number of glider pilots will buy these systems and not invest an extra $2K in a transponder. Some pilots may elect to invest in portable UAT transceivers that they can share in a club environment.

You need more than just the transceivers - you need the control interface and the display system - AND an electrical system to power it. All that for less than $1000? I hope so, but I'm not holding my breath!

>
> This will not make the glider visible to today's airliner TCAS systems, but it will make the glider visible on ATC radar. Hopefully ATC will have the common sense to vector any traffic around you. In addition, the UAT transceiver equipped glider will clearly see the big iron traffic and be able to stay out of the way.

So, if my concern is about fast movers (out West, or near a Class B airport, I'm still better off with a Mode S transponder, and eventually add the ADS-B ES kit to get full ADS-B if I want the weather. And sure, if the magical cheap UAT device starts popping up in all the flying machines in my vicinity, then I would get one too. But until all this fantasy gear is reality, I'll continue to be protected by my PowerFLARM.

And again: Would you please spec out for me your idea of an actual UAT-based ADS-B system (hardware, software, cost) that one can buy TODAY and install in their glider, that provides at least as much situational awareness as the PowerFLARM has been providing me for the past 3 years? So far, all I see is talk - but nothing remotely useful coming out of your mouth. Step up, man!

Kirk
66

Mike Schumann[_2_]

May 6th 15, 06:19 AM

On Tuesday, May 5, 2015 at 10:52:06 AM UTC-4, kirk.stant wrote:
> On Monday, May 4, 2015 at 5:02:29 PM UTC-5, Mike Schumann wrote:
>
> > You are totally mistaken that everyone who installs ADS-B OUT needs to have a Mode C or Mode S transponder. For starters, gliders are totally exempt from both the ADS-B OUT and transponder mandates. That also applies to all other aircraft that either do not have electrical systems, or operate outside of the Mode C veil and below 10,000 ft.
>
> Oh get real, Mike. The subset of aircraft that are exempt from the transponder mandate that will bother to put anykind of ADS-B is pretty small. At best, there will be a relatively cheap battery-powered system developed that will fill that niche (ultralights, powered chutes - and maybe some training gliders/towplanes. But for the rest of the aviation world, the need to fly above 10,000 and in Class C/B airspace means transponders. And if you don't need to fly there, they won't bother with any ADS-B - heck, many club gliders in the US don't even have radios!
>
> >
> > With the cost of ADS-B OUT UAT transceivers dropping below $1,000 it is totally conceivable that a significant number of glider pilots will buy these systems and not invest an extra $2K in a transponder. Some pilots may elect to invest in portable UAT transceivers that they can share in a club environment.
>
> You need more than just the transceivers - you need the control interface and the display system - AND an electrical system to power it. All that for less than $1000? I hope so, but I'm not holding my breath!
>
> >
> > This will not make the glider visible to today's airliner TCAS systems, but it will make the glider visible on ATC radar. Hopefully ATC will have the common sense to vector any traffic around you. In addition, the UAT transceiver equipped glider will clearly see the big iron traffic and be able to stay out of the way.
>
> So, if my concern is about fast movers (out West, or near a Class B airport, I'm still better off with a Mode S transponder, and eventually add the ADS-B ES kit to get full ADS-B if I want the weather. And sure, if the magical cheap UAT device starts popping up in all the flying machines in my vicinity, then I would get one too. But until all this fantasy gear is reality, I'll continue to be protected by my PowerFLARM.
>
> And again: Would you please spec out for me your idea of an actual UAT-based ADS-B system (hardware, software, cost) that one can buy TODAY and install in their glider, that provides at least as much situational awareness as the PowerFLARM has been providing me for the past 3 years? So far, all I see is talk - but nothing remotely useful coming out of your mouth. Step up, man!
>
> Kirk
> 66

If you want a fully functional ADS-B IN / OUT system for under $1,000 you'll probably have to wait until this fall. These systems are going to use iPAD or iPHONE apps to provide the user interface. (I'm not counting the cost of iPhone / iPAD in the price of the system, as most people have these devices anyway).

At this price point, these devices are going to be very popular in the General Aviation community. It's perplexing to me why the PowerFLARM guys don't get with the program and come up with a dual frequency ADS-B receiver or support TIS-B and ADS-R so they can have a competitive product in this space.

2KA

May 6th 15, 06:56 PM

> ... For starters, gliders are totally exempt from both the ADS-B OUT and transponder mandates.

Is that really true? The way I am reading the mandate, ADS-B OUT will be required for gliders that operate inside the Mode-C veil and above 10,000 feet. I know that doesn't apply to most of us, but there are at least several operations in the West that will be directly impacted. I'd love to be mistaken about this.

Mike Schumann[_2_]

May 6th 15, 09:13 PM

On Wednesday, May 6, 2015 at 1:56:11 PM UTC-4, 2KA wrote:
> > ... For starters, gliders are totally exempt from both the ADS-B OUT and transponder mandates.
>
> Is that really true? The way I am reading the mandate, ADS-B OUT will be required for gliders that operate inside the Mode-C veil and above 10,000 feet. I know that doesn't apply to most of us, but there are at least several operations in the West that will be directly impacted. I'd love to be mistaken about this.

See https://www.law.cornell.edu/cfr/text/14/91.225

The relevant section is 91.225(e). It specifically permits operation of gliders without being ADS-B OUT equipped inside the Mode C veil and above 10,000 ft as long as you are not operating in Class A, B, or C airspace. Note: You also can not operate above Class B airspace in a glider if you are not ADS-B OUT equipped.

Another interesting requirement is that above 18,000 ft, you need to be 1090ES ADS-B OUT equipped. While the statute permits you to operate with an ATC waiver, there is no guarantee that this will be authorized. It's up to the local ATC jurisdiction to make the call. It will be interesting to see how this is handled with Wave windows. Hopefully the downward pricing trends of UAT ADS-B OUT equipment will also put pressure on 1090ES vendors to sharpen their pencils. If I were planning on flying in Wave, I would probably look pretty hard at using a 1090ES solution vs. a lower cost UAT transmitter.

[email protected]

May 6th 15, 10:31 PM

91.225 (e)2 confuses me.

(e) The requirements of paragraph (b) of this section do not apply to any aircraft that was not originally certificated with an electrical system, or that has not subsequently been certified with such a system installed, including balloons and gliders. These aircraft may conduct operations without ADS-B Out in the airspace specified in paragraphs (d)(2) and (d)(4) of this section. Operations authorized by this section must be conducted--

(1) Outside any Class B or Class C airspace area; and

(2) Below the altitude of the ceiling of a Class B or Class C airspace area designated for an airport, or 10,000 feet MSL, whichever is lower.

This states that I must be below 10,000 feet MSL in my non-equipped glider. Doesn't it ?

Todd

2KA

May 7th 15, 12:15 AM

Yup, there is definitely something wrong with the language of 91.225(e), particularly 91.225(e)(2). On the one hand, it says "these aircraft may conduct operations without ADSB-Out in the airspace specified in paragraphs... (d)(4)" -- note that (d)(4) applies ONLY above 10,000 feet -- and on the other hand it says "Operations Authorized... must be conducted... Below... 10,000 MSL".

Seems to me that those two sentences are contradictory. Why would they give an exception to (d)(4) that can never be used because of (e)(2)?

Bill T

May 7th 15, 04:11 AM

There was is Nothing wrong with the language, it is the same as for the transponder requirement.
Within the 30nm arc defining the mode c veil, if the ceiling of the associated class b is 9000msl, you cannot climb above 9000 without the proper equipment.
If the class b goes to 10,000msl, no problem, climb as high as you like to 17,999.

You cannont fly over the top of Class B or Class C below 10,000 MSL. TFR the Class C tops out at 5,000, you cannot fly between 5,000 and 10,000 without equipment. Above 10,000 to 17,999 is fair game.

BillT

Andy Blackburn[_3_]

May 7th 15, 05:32 AM

On Tuesday, May 5, 2015 at 10:19:59 PM UTC-7, Mike Schumann wrote:
>
> If you want a fully functional ADS-B IN / OUT system for under $1,000 you'll probably have to wait until this fall. These systems are going to use iPAD or iPHONE apps to provide the user interface. (I'm not counting the cost of iPhone / iPAD in the price of the system, as most people have these devices anyway).
>
If I'm flying a glider and I want to invest in avionics for anti-collision I wouldn't invest in anything that doesn't sent/receive Flarm protocol if I'm worried about gliders since the odds a glider is going to have anything other than Flarm is low. If I'm worried about fast jets I wouldn't invest in anything that doesn't light up both TCAS and SSR because they are faster it is much better for them to see me. That requires a transponder. Those considerations make anything UAT-only mostly useless as it depends on ADS-R to get even half of the job done. For GA I remain skeptical that UAT will outsell 1090ES, even in GA.

9B

Mike Schumann[_2_]

May 7th 15, 07:08 AM

On Thursday, May 7, 2015 at 12:32:11 AM UTC-4, Andy Blackburn wrote:
> On Tuesday, May 5, 2015 at 10:19:59 PM UTC-7, Mike Schumann wrote:
> >
> > If you want a fully functional ADS-B IN / OUT system for under $1,000 you'll probably have to wait until this fall. These systems are going to use iPAD or iPHONE apps to provide the user interface. (I'm not counting the cost of iPhone / iPAD in the price of the system, as most people have these devices anyway).
> >
> If I'm flying a glider and I want to invest in avionics for anti-collision I wouldn't invest in anything that doesn't sent/receive Flarm protocol if I'm worried about gliders since the odds a glider is going to have anything other than Flarm is low. If I'm worried about fast jets I wouldn't invest in anything that doesn't light up both TCAS and SSR because they are faster it is much better for them to see me. That requires a transponder. Those considerations make anything UAT-only mostly useless as it depends on ADS-R to get even half of the job done. For GA I remain skeptical that UAT will outsell 1090ES, even in GA.
>
> 9B

The question is, do you want to end up with an avionics package that doesn't see UAT ADS-B OUT equipped traffic? It's hard to predict how much of the GA or UAV fleet will go down that road, but it could be a pretty significant percentage if there is a significant price difference between UAT and 1090ES ADS-B OUT solutions.

That's not to say that FLARM isn't a good solution for glider pilots that are flying in competitions. FLARM is specifically designed for collision avoidance for aircraft that are flying at close quarters. ADS-B is designed to give people a heads up so they can stay far away from any conflicting traffic before it becomes a threat. It's really unfortunate that the PowerFLARM folks only solved part of the problem rather than come up with a comprehensive solution that takes into account the UAT / 1090ES architecture of the US ADS-B system.

waremark

May 7th 15, 08:21 AM

In Europe I don't think this is even a discussion. The risk to gliders is nearly all glider to glider. Some GA owners are installing PF also.

kirk.stant

May 7th 15, 03:40 PM

On Thursday, May 7, 2015 at 1:08:27 AM UTC-5, Mike Schumann wrote:

> The question is, do you want to end up with an avionics package that doesn't see UAT ADS-B OUT equipped traffic? It's hard to predict how much of the GA or UAV fleet will go down that road, but it could be a pretty significant percentage if there is a significant price difference between UAT and 1090ES ADS-B OUT solutions.

The problem is, in order to see ALL ADS-B traffic, you HAVE to have ADS-B out. So to get reliable info, you have to have, at a minimum, about $1500 for a Skyguard UAT transceiver and and $500 for an iFly display to show the data. Or an iPhone 6+, same price.

And how many gliders are going to do that? Most racers won't - they'll stick to PF for the collision warning advantage (and leeching benefits). Out west, they will most likely go with 1090ES out to trigger jet TCAS, and PF to see other gliders.

Just getting an ADS-B receiver is fine for weather and NOTAMS, but a really flawed solution for traffic - much worse than PF, for all the reasons that have been discussed ad nauseum in this thread.

> That's not to say that FLARM isn't a good solution for glider pilots that are flying in competitions. FLARM is specifically designed for collision avoidance for aircraft that are flying at close quarters. ADS-B is designed to give people a heads up so they can stay far away from any conflicting traffic before it becomes a threat. It's really unfortunate that the PowerFLARM folks only solved part of the problem rather than come up with a comprehensive solution that takes into account the UAT / 1090ES architecture of the US ADS-B system.

Mike, has it occurred to you that since the US is the only country to use UAT, there isn't a big enough market for it at present? But in Europe, the PF makes total sense, since it will display ALL ADS-B (1090ES) traffic AND gliders?

Kirk
66

[email protected]

May 7th 15, 06:06 PM

On Wednesday, May 6, 2015 at 11:11:33 PM UTC-4, Bill T wrote:
> There was is Nothing wrong with the language, it is the same as for the transponder requirement.
> Within the 30nm arc defining the mode c veil, if the ceiling of the associated class b is 9000msl, you cannot climb above 9000 without the proper equipment.
> If the class b goes to 10,000msl, no problem, climb as high as you like to 17,999.
>
> You cannont fly over the top of Class B or Class C below 10,000 MSL. TFR the Class C tops out at 5,000, you cannot fly between 5,000 and 10,000 without equipment. Above 10,000 to 17,999 is fair game.
>
> BillT

Bill,

They might have wanted it to be the same as the transponder, but they used different language. The only way I can parse the FAR is that there is no exemption above 10,000 MSL.

Todd
3S

[email protected]

May 7th 15, 06:20 PM

On Thursday, May 7, 2015 at 7:40:59 AM UTC-7, kirk.stant wrote:
> The problem is, in order to see ALL ADS-B traffic, you HAVE to have ADS-B out. So to get reliable info, you have to have, at a minimum, about $1500 for a Skyguard UAT transceiver and and $500 for an iFly display to show the data. Or an iPhone 6+, same price.
>
Uh no, to see all ADS-B traffic you just need to have receivers for both UAT and 1090ES, both transmit continuously whether or not there is other ADS-B traffic in the area. It is ADS-R from ground stations that may not be transmitted if there are no detected ADS-B out targets in the area.

Benedict Smith

May 7th 15, 08:13 PM

At 07:21 07 May 2015, waremark wrote:
>In Europe I don't think this is even a discussion. The risk to gliders is
>nearly all glider to glider. Some GA owners are installing PF also.
>
Not just GA! The Vulcan bomber is installing PF this spring and the RAF
BBMF
have installed it in all their aircraft.

kirk.stant

May 7th 15, 10:14 PM

On Thursday, May 7, 2015 at 12:20:41 PM UTC-5, wrote:

> Uh no, to see all ADS-B traffic you just need to have receivers for both UAT and 1090ES, both transmit continuously whether or not there is other ADS-B traffic in the area. It is ADS-R from ground stations that may not be transmitted if there are no detected ADS-B out targets in the area.

Are you sure? As I understand it, unless you transmit ADS-B out, you will not get all the UAT ADS-B out traffic. You will only see them when a UAT ADS-B out is getting traffic info for all the traffic near him. And you have to be in range of a ground station.

Agree that with a 1090ES receiver (such as a PF), you will see all 1090ES traffic nearby - but not UAT-only ADS-B traffic.

Kirk
66

[email protected]

May 8th 15, 01:52 AM

On Thursday, May 7, 2015 at 2:14:58 PM UTC-7, kirk.stant wrote:
> Are you sure? As I understand it, unless you transmit ADS-B out, you will not get all the UAT ADS-B out traffic. You will only see them when a UAT ADS-B out is getting traffic info for all the traffic near him. And you have to be in range of a ground station.

1090ES and UAT ADS-B out devices continuously transmit position and velocity vector once or twice per second (I'm hazy on which it is). A ground station may suppress transmission of TIS-B and ADS-R, if there is no ADS-B target of the corresponding type in the coverage area.

Marc

son_of_flubber

May 8th 15, 02:26 AM

On Thursday, May 7, 2015 at 3:15:06 PM UTC-4, Benedict Smith wrote:
> The Vulcan bomber is installing PF this spring and the RAF
> BBMF
> have installed it in all their aircraft.

Is this to avoid transponder-less gliders or are they installing PF to avoid collision with other bombers in close formation flying? I wonder what sorts of testing they did.

Bill T

May 8th 15, 04:26 AM

It's all in there, 91.225. Concentrate on (d)(2) and (d)(4) and (e).
(e) is your (d)(4) exemption for above 10,000
(e)(1) and (e)(2) applies to the 30nm veil referenced in (d)(2)
Although it is not very clear.

BillT

Andy Blackburn[_3_]

May 8th 15, 06:19 AM

On Wednesday, May 6, 2015 at 11:08:27 PM UTC-7, Mike Schumann wrote:

> The question is, do you want to end up with an avionics package that doesn't see UAT ADS-B OUT equipped traffic? It's hard to predict how much of the GA or UAV fleet will go down that road, but it could be a pretty significant percentage if there is a significant price difference between UAT and 1090ES ADS-B OUT solutions.

That's not really the right question. The question is how do you trade off total cost versus the probability of potential collision scenarios.

If you can only afford a single device for most glider pilots the right choice is a PowerFlarm, which will get you anticollision for other PF-equipped gliders, plus PCAS for all transponder-equipped aircraft being painted by SSR or TCAS, plus 1090ES In for most (and in 2020 ALL) aircraft that fly in Class A.

Under some less common circumstances your best choice if you can afford only once device is to buy a transponder (preferably Mode S). This will make you visible to most high-performance aircraft equipped with TCAS AND to SSR AND to GA with PCAS. Modern Mode S transponders also have an upgrade path to 1090ES Out which will make you visible to most ADS-B equipped aircraft either directly or via ADS-R. Keep in mind that it is generally better for the higher performance aircraft to detect the lower performance aircraft rather than the other way around as they have more degrees of freedom.

If you can afford two devices you are best off installing a PowerFlarm AND a transponder. This will allow you to see and/or be seen by all transponder, PowerFlarm and 1090ES Out aircraft and will allow you to upgrade to 1090ES Out which will also make you visible to aircraft carrying UAT In/Out but aren't carrying a transponder or talking to ATC - not sure how many of these there will be given the regulations overlap between ADS-B and transponders.

If you want to install three devices you can consider UAT-In - this will additionally give you coverage of aircraft that are not carrying a transponder but are carrying UAT Out. It will also allow you better granularity in seeing UAT-Out aircraft and any UAVs that are flying outside MOAs or wander above the 400' FAA limit ASSUMING they are equipped with UAT instead of 1090ES - not clear that UAVs are going to be a big deal or that UAT would be preferred to 1090ES for them. Based on the statistics, this does not seem like a good return on investment in terms of risk reduction. I am personally skeptical that many GA aircraft will equip with UAT Out over 1090ES Out and am particularly skeptical that they will eschew transponder carriage so you wouldn't see them on PowerFlarm's PCAS.

The idea of picking UAT In before PowerFlarm and/or a Mode S transponder defies all the traffic, equipment and collision statistics. If you want it as a third device knock yourself out, but it is definitely well past the point of diminishing returns.

9B

Mike Schumann[_2_]

May 8th 15, 06:51 AM

On Friday, May 8, 2015 at 1:19:30 AM UTC-4, Andy Blackburn wrote:
> On Wednesday, May 6, 2015 at 11:08:27 PM UTC-7, Mike Schumann wrote:
>
> > The question is, do you want to end up with an avionics package that doesn't see UAT ADS-B OUT equipped traffic? It's hard to predict how much of the GA or UAV fleet will go down that road, but it could be a pretty significant percentage if there is a significant price difference between UAT and 1090ES ADS-B OUT solutions.
>
> That's not really the right question. The question is how do you trade off total cost versus the probability of potential collision scenarios.
>
> If you can only afford a single device for most glider pilots the right choice is a PowerFlarm, which will get you anticollision for other PF-equipped gliders, plus PCAS for all transponder-equipped aircraft being painted by SSR or TCAS, plus 1090ES In for most (and in 2020 ALL) aircraft that fly in Class A.
>
> Under some less common circumstances your best choice if you can afford only once device is to buy a transponder (preferably Mode S). This will make you visible to most high-performance aircraft equipped with TCAS AND to SSR AND to GA with PCAS. Modern Mode S transponders also have an upgrade path to 1090ES Out which will make you visible to most ADS-B equipped aircraft either directly or via ADS-R. Keep in mind that it is generally better for the higher performance aircraft to detect the lower performance aircraft rather than the other way around as they have more degrees of freedom.
>
> If you can afford two devices you are best off installing a PowerFlarm AND a transponder. This will allow you to see and/or be seen by all transponder, PowerFlarm and 1090ES Out aircraft and will allow you to upgrade to 1090ES Out which will also make you visible to aircraft carrying UAT In/Out but aren't carrying a transponder or talking to ATC - not sure how many of these there will be given the regulations overlap between ADS-B and transponders.
>
> If you want to install three devices you can consider UAT-In - this will additionally give you coverage of aircraft that are not carrying a transponder but are carrying UAT Out. It will also allow you better granularity in seeing UAT-Out aircraft and any UAVs that are flying outside MOAs or wander above the 400' FAA limit ASSUMING they are equipped with UAT instead of 1090ES - not clear that UAVs are going to be a big deal or that UAT would be preferred to 1090ES for them. Based on the statistics, this does not seem like a good return on investment in terms of risk reduction. I am personally skeptical that many GA aircraft will equip with UAT Out over 1090ES Out and am particularly skeptical that they will eschew transponder carriage so you wouldn't see them on PowerFlarm's PCAS.
>
> The idea of picking UAT In before PowerFlarm and/or a Mode S transponder defies all the traffic, equipment and collision statistics. If you want it as a third device knock yourself out, but it is definitely well past the point of diminishing returns.
>
> 9B

Everyone is going to have somewhat different priorities depending on what kind of flying they do. Competition pilots are obviously going to be focused on FLARM due to their close proximity to other gliders many of whom are presumably also going to be FLARM equipped.

Those of us who fly recreationally near major metropolitan areas in the midwest have a different threat scenario. Most of the time, the big iron is not a factor, as they are flying higher than we can reach in a thermal. We will encounter sporadic regional or private jet traffic. What is a big factor, particularly when you are close to an airport is other GA traffic. In this environment a fully functional ADS-B IN system (coupled with ADS-B OUT) is very helpful in giving you the big picture of exactly where everyone else is. Virtually all of the ADS-B IN systems sold in the US (except PowerFLARM) support TIS-B and will show you exactly where all transponder equipped aircraft are if you are within range of an ADS-B ground station and you are ADS-B OUT equipped.

Your assumptions about the limited threats posed by UAV traffic may be accurate today, but wildly off the mark in the not too distant future. Once the FAA gets their act together, we are going to see an explosion of UAV applications for pipeline monitoring, agricultural spraying, aerial photography, news gathering, law enforcement, etc.... The economics of this technology is compelling. Many of these applications are going to be in rural areas where you would least expect to encounter another aircraft. All of these UAVs are going to be ADS-B equipped. Whether it will be UAT or 1090ES is anyone's guess at this point. My personal feeling is that there will be a lot of UAT ADS-B OUT equipage, unless there is a dramatic reduction in the price difference between these technologies.

The final question that everyone has to face is the when to equip. This is a very rapidly evolving field with significant price reductions and capability advances happening in a relatively short time horizon. Everyone is going to have to make their own decision on when to pull the trigger, given their willingness to risk technological obsolescence if they buy the wrong product too early.

Andy Blackburn[_3_]

May 8th 15, 01:18 PM

On Thursday, May 7, 2015 at 10:51:33 PM UTC-7, Mike Schumann wrote:
> On Friday, May 8, 2015 at 1:19:30 AM UTC-4, Andy Blackburn wrote:
> > On Wednesday, May 6, 2015 at 11:08:27 PM UTC-7, Mike Schumann wrote:
> >
> > > The question is, do you want to end up with an avionics package that doesn't see UAT ADS-B OUT equipped traffic? It's hard to predict how much of the GA or UAV fleet will go down that road, but it could be a pretty significant percentage if there is a significant price difference between UAT and 1090ES ADS-B OUT solutions.
> >
> > That's not really the right question. The question is how do you trade off total cost versus the probability of potential collision scenarios.
> >
> > If you can only afford a single device for most glider pilots the right choice is a PowerFlarm, which will get you anticollision for other PF-equipped gliders, plus PCAS for all transponder-equipped aircraft being painted by SSR or TCAS, plus 1090ES In for most (and in 2020 ALL) aircraft that fly in Class A.
> >
> > Under some less common circumstances your best choice if you can afford only once device is to buy a transponder (preferably Mode S). This will make you visible to most high-performance aircraft equipped with TCAS AND to SSR AND to GA with PCAS. Modern Mode S transponders also have an upgrade path to 1090ES Out which will make you visible to most ADS-B equipped aircraft either directly or via ADS-R. Keep in mind that it is generally better for the higher performance aircraft to detect the lower performance aircraft rather than the other way around as they have more degrees of freedom.
> >
> > If you can afford two devices you are best off installing a PowerFlarm AND a transponder. This will allow you to see and/or be seen by all transponder, PowerFlarm and 1090ES Out aircraft and will allow you to upgrade to 1090ES Out which will also make you visible to aircraft carrying UAT In/Out but aren't carrying a transponder or talking to ATC - not sure how many of these there will be given the regulations overlap between ADS-B and transponders.
> >
> > If you want to install three devices you can consider UAT-In - this will additionally give you coverage of aircraft that are not carrying a transponder but are carrying UAT Out. It will also allow you better granularity in seeing UAT-Out aircraft and any UAVs that are flying outside MOAs or wander above the 400' FAA limit ASSUMING they are equipped with UAT instead of 1090ES - not clear that UAVs are going to be a big deal or that UAT would be preferred to 1090ES for them. Based on the statistics, this does not seem like a good return on investment in terms of risk reduction. I am personally skeptical that many GA aircraft will equip with UAT Out over 1090ES Out and am particularly skeptical that they will eschew transponder carriage so you wouldn't see them on PowerFlarm's PCAS.
> >
> > The idea of picking UAT In before PowerFlarm and/or a Mode S transponder defies all the traffic, equipment and collision statistics. If you want it as a third device knock yourself out, but it is definitely well past the point of diminishing returns.
> >
> > 9B
>
> Everyone is going to have somewhat different priorities depending on what kind of flying they do. Competition pilots are obviously going to be focused on FLARM due to their close proximity to other gliders many of whom are presumably also going to be FLARM equipped.
>
> Those of us who fly recreationally near major metropolitan areas in the midwest have a different threat scenario. Most of the time, the big iron is not a factor, as they are flying higher than we can reach in a thermal. We will encounter sporadic regional or private jet traffic. What is a big factor, particularly when you are close to an airport is other GA traffic. In this environment a fully functional ADS-B IN system (coupled with ADS-B OUT) is very helpful in giving you the big picture of exactly where everyone else is. Virtually all of the ADS-B IN systems sold in the US (except PowerFLARM) support TIS-B and will show you exactly where all transponder equipped aircraft are if you are within range of an ADS-B ground station and you are ADS-B OUT equipped.
>
> Your assumptions about the limited threats posed by UAV traffic may be accurate today, but wildly off the mark in the not too distant future. Once the FAA gets their act together, we are going to see an explosion of UAV applications for pipeline monitoring, agricultural spraying, aerial photography, news gathering, law enforcement, etc.... The economics of this technology is compelling. Many of these applications are going to be in rural areas where you would least expect to encounter another aircraft. All of these UAVs are going to be ADS-B equipped. Whether it will be UAT or 1090ES is anyone's guess at this point. My personal feeling is that there will be a lot of UAT ADS-B OUT equipage, unless there is a dramatic reduction in the price difference between these technologies.
>
> The final question that everyone has to face is the when to equip. This is a very rapidly evolving field with significant price reductions and capability advances happening in a relatively short time horizon. Everyone is going to have to make their own decision on when to pull the trigger, given their willingness to risk technological obsolescence if they buy the wrong product too early.

Unfortunately your analysis is undercut by the actual accident data over the past 20 years, so for the vast majority of glider pilots in the US it does not represent the actual threat scenario they are facing. That may be either because your situation is not typical or because your analysis is flawed. If you are the ONLY glider flying at an airport that is basically in the traffic pattern for lots of GA aircraft your analysis may be correct, but quite unlike most other glider fields in the US and therefore not a basis for making statements about what other glider pilots should do.

If, like most other gliderports in the US, you have more than a couple of other gliders flying from your airport and you are more than 5 miles from a major GA airport then the probabilities flip substantially towards glider-glider or glider-towplane. In this situation PowerFlarm becomes the better option. The reason this is true is because collision risk goes down with the square of the distance of the source of traffic. Plus if you are within range of SSR, PowerFlarm will give you transponder equipped traffic warnings.. Having the nice picture of all the aircraft within 20-30 miles on you iPad might be fun, but it's not really a big incremental benefit in avoiding collisions.

The UAV statements are pretty wild speculation and sound to me like a fear-mongering distraction that gets raised only because UAT is not relevant in most aircraft scenarios to which glider pilots should pay attention. I seriously doubt the FAA is going to permit large numbers of military UAVs or commercial drones unfettered access to anything outside class G airspace (or maybe lower) unless it's in a MOA. None of the applications you mention require (in fact they'd be less well served) by drones flying above 700' AGL anyway. It's just so unlikely to be a factor to gliders and takes attention away from the collision scenarios that really matter today.

Your "when to equip" statement is generally correct. UAT has practically no usefulness now to glider pilots due to extremely limited UAT-Out deployment and lack of UAT-In integration into any glider instrumentation or displays. Of all the alternatives for gliders today UAT has the highest risk of being a wasted investment in the future. Glider pilots can safely avoid buying it and should it become something that actually gets deployed in numbers sometime before 2020 and in a way that their already installed PowerFlarm and/or transponder doesn't adequately serve (via PCAS for instance), my guess is that the Flarm folks (or others) would respond with an add-on module that can merge UAT traffic into the NMEA stream for integration with traffic from other sources -- or maybe glider pilots can buy that $300 bluetooth UAT-In receiver (that doesn't yet exist) so they can stare at UAT traffic (without collision warnings) on their iPhones.

In any case the action plan now should be PowerFlarm and/or transponder. Wait for anything additional. The next best investment would likely be 1090ES-Out which will make you visible to anyone with 1090ES-In OR UAT-In plus ATC. If you really want to see UAT-Only traffic, by the time it became a factor the UAT-In modules ought to be cheaper. I think we can all agree that it'll never make sense for gliders to equip with UAT-Out.

9B

Andy Blackburn[_3_]

May 8th 15, 01:26 PM

On Friday, May 8, 2015 at 5:18:48 AM UTC-7, Andy Blackburn wrote:
> On Thursday, May 7, 2015 at 10:51:33 PM UTC-7, Mike Schumann wrote:
> > On Friday, May 8, 2015 at 1:19:30 AM UTC-4, Andy Blackburn wrote:
> > > On Wednesday, May 6, 2015 at 11:08:27 PM UTC-7, Mike Schumann wrote:
> > >
> > > > The question is, do you want to end up with an avionics package that doesn't see UAT ADS-B OUT equipped traffic? It's hard to predict how much of the GA or UAV fleet will go down that road, but it could be a pretty significant percentage if there is a significant price difference between UAT and 1090ES ADS-B OUT solutions.
> > >
> > > That's not really the right question. The question is how do you trade off total cost versus the probability of potential collision scenarios.
> > >
> > > If you can only afford a single device for most glider pilots the right choice is a PowerFlarm, which will get you anticollision for other PF-equipped gliders, plus PCAS for all transponder-equipped aircraft being painted by SSR or TCAS, plus 1090ES In for most (and in 2020 ALL) aircraft that fly in Class A.
> > >
> > > Under some less common circumstances your best choice if you can afford only once device is to buy a transponder (preferably Mode S). This will make you visible to most high-performance aircraft equipped with TCAS AND to SSR AND to GA with PCAS. Modern Mode S transponders also have an upgrade path to 1090ES Out which will make you visible to most ADS-B equipped aircraft either directly or via ADS-R. Keep in mind that it is generally better for the higher performance aircraft to detect the lower performance aircraft rather than the other way around as they have more degrees of freedom.
> > >
> > > If you can afford two devices you are best off installing a PowerFlarm AND a transponder. This will allow you to see and/or be seen by all transponder, PowerFlarm and 1090ES Out aircraft and will allow you to upgrade to 1090ES Out which will also make you visible to aircraft carrying UAT In/Out but aren't carrying a transponder or talking to ATC - not sure how many of these there will be given the regulations overlap between ADS-B and transponders.
> > >
> > > If you want to install three devices you can consider UAT-In - this will additionally give you coverage of aircraft that are not carrying a transponder but are carrying UAT Out. It will also allow you better granularity in seeing UAT-Out aircraft and any UAVs that are flying outside MOAs or wander above the 400' FAA limit ASSUMING they are equipped with UAT instead of 1090ES - not clear that UAVs are going to be a big deal or that UAT would be preferred to 1090ES for them. Based on the statistics, this does not seem like a good return on investment in terms of risk reduction. I am personally skeptical that many GA aircraft will equip with UAT Out over 1090ES Out and am particularly skeptical that they will eschew transponder carriage so you wouldn't see them on PowerFlarm's PCAS.
> > >
> > > The idea of picking UAT In before PowerFlarm and/or a Mode S transponder defies all the traffic, equipment and collision statistics. If you want it as a third device knock yourself out, but it is definitely well past the point of diminishing returns.
> > >
> > > 9B
> >
> > Everyone is going to have somewhat different priorities depending on what kind of flying they do. Competition pilots are obviously going to be focused on FLARM due to their close proximity to other gliders many of whom are presumably also going to be FLARM equipped.
> >
> > Those of us who fly recreationally near major metropolitan areas in the midwest have a different threat scenario. Most of the time, the big iron is not a factor, as they are flying higher than we can reach in a thermal. We will encounter sporadic regional or private jet traffic. What is a big factor, particularly when you are close to an airport is other GA traffic. In this environment a fully functional ADS-B IN system (coupled with ADS-B OUT) is very helpful in giving you the big picture of exactly where everyone else is. Virtually all of the ADS-B IN systems sold in the US (except PowerFLARM) support TIS-B and will show you exactly where all transponder equipped aircraft are if you are within range of an ADS-B ground station and you are ADS-B OUT equipped.
> >
> > Your assumptions about the limited threats posed by UAV traffic may be accurate today, but wildly off the mark in the not too distant future. Once the FAA gets their act together, we are going to see an explosion of UAV applications for pipeline monitoring, agricultural spraying, aerial photography, news gathering, law enforcement, etc.... The economics of this technology is compelling. Many of these applications are going to be in rural areas where you would least expect to encounter another aircraft. All of these UAVs are going to be ADS-B equipped. Whether it will be UAT or 1090ES is anyone's guess at this point. My personal feeling is that there will be a lot of UAT ADS-B OUT equipage, unless there is a dramatic reduction in the price difference between these technologies.
> >
> > The final question that everyone has to face is the when to equip. This is a very rapidly evolving field with significant price reductions and capability advances happening in a relatively short time horizon. Everyone is going to have to make their own decision on when to pull the trigger, given their willingness to risk technological obsolescence if they buy the wrong product too early.
>
> Unfortunately your analysis is undercut by the actual accident data over the past 20 years, so for the vast majority of glider pilots in the US it does not represent the actual threat scenario they are facing. That may be either because your situation is not typical or because your analysis is flawed. If you are the ONLY glider flying at an airport that is basically in the traffic pattern for lots of GA aircraft your analysis may be correct, but quite unlike most other glider fields in the US and therefore not a basis for making statements about what other glider pilots should do.
>
> If, like most other gliderports in the US, you have more than a couple of other gliders flying from your airport and you are more than 5 miles from a major GA airport then the probabilities flip substantially towards glider-glider or glider-towplane. In this situation PowerFlarm becomes the better option. The reason this is true is because collision risk goes down with the square of the distance of the source of traffic. Plus if you are within range of SSR, PowerFlarm will give you transponder equipped traffic warnings. Having the nice picture of all the aircraft within 20-30 miles on you iPad might be fun, but it's not really a big incremental benefit in avoiding collisions.
>
> The UAV statements are pretty wild speculation and sound to me like a fear-mongering distraction that gets raised only because UAT is not relevant in most aircraft scenarios to which glider pilots should pay attention. I seriously doubt the FAA is going to permit large numbers of military UAVs or commercial drones unfettered access to anything outside class G airspace (or maybe lower) unless it's in a MOA. None of the applications you mention require (in fact they'd be less well served) by drones flying above 700' AGL anyway. It's just so unlikely to be a factor to gliders and takes attention away from the collision scenarios that really matter today.
>
> Your "when to equip" statement is generally correct. UAT has practically no usefulness now to glider pilots due to extremely limited UAT-Out deployment and lack of UAT-In integration into any glider instrumentation or displays. Of all the alternatives for gliders today UAT has the highest risk of being a wasted investment in the future. Glider pilots can safely avoid buying it and should it become something that actually gets deployed in numbers sometime before 2020 and in a way that their already installed PowerFlarm and/or transponder doesn't adequately serve (via PCAS for instance), my guess is that the Flarm folks (or others) would respond with an add-on module that can merge UAT traffic into the NMEA stream for integration with traffic from other sources -- or maybe glider pilots can buy that $300 bluetooth UAT-In receiver (that doesn't yet exist) so they can stare at UAT traffic (without collision warnings) on their iPhones.
>
> In any case the action plan now should be PowerFlarm and/or transponder. Wait for anything additional. The next best investment would likely be 1090ES-Out which will make you visible to anyone with 1090ES-In OR UAT-In plus ATC. If you really want to see UAT-Only traffic, by the time it became a factor the UAT-In modules ought to be cheaper. I think we can all agree that it'll never make sense for gliders to equip with UAT-Out.
>
> 9B

Sorry, I missed an important point. Even if Mike operates in some crazy world with all GA and no gliders or towplanes his scenario still requires GA to deploy UAT. That hasn't happened yet - it's mostly 1090ES out there today, so the world has to skew significantly towards UA Out for it to be of use..

9B