Flarm in the US

Let's take a real life example. Last year I flew in Sports Nationals
in Elmira. I had PCAS with me. The first day after I released and
started climbing with a bunch of other gliders many of them equipped
with transponders I had to switch my PCAS off because of the quantity
of warnings. It was useless in that scenario.

Now, isn't a PowerFlarm unit a FLARM and PCAS in one box? Can I switch
off PCAS while leaving FLARM on when I am in a thermal with a bunch of
transponder equipped gliders so I don't get overwhelmed by warnings.
Once on task I could turn PCAS back on but in a congested thermal I
may not want to see it on.

Anyone knows how this situation would be handled by PowerFlarm?

On Aug 11, 11:15*am, Ramy wrote:
On Aug 11, 9:23*am, Darryl Ramm wrote:



On Aug 11, 8:07*am, William Gagen wrote:

FLARM - We NEED it yesterday.

How many more midairs do we need to have in our sport?

What if we have a midair with an airliner? Can you say soaring as a
sport is dead, as the FAA will reflexively eliminate all of our
flexibility.

The cost of FLARM in any form is negligible compared to staying
alive.

I have used FLARM at the IMGC Competition (International Military
Glider Comp) in Germany, and it turned a competition with 93 gliders
into the safest competition I have ever flown in anywhere.

It provides timely, accurate, important alerts for collision potential
with very few spurious or distracting warnings. It is vastly superior
to PCAS. There is absolutely no reason we shouldn't be requiring it
for all competition aircraft PERIOD!

The following midairs could all have been prevented by FLARM: Parowan
this summer, Uvalde this summer, Boulder last winter, the Hudson River
helicopter/light plane midair.

Thanks for reading my rant. But, having used it, I know how good it
is, and why we need it yesterday!

SSA could be helpful by providing loaner or rental FLARM units to
aircraft to use in competitions. In this way, we could get them into
every competition sooner. A pilot could rent a unit for say $100 a
competition, and over 2 summers the units would be paid off.

There is a gamut of collision scenarios from glider-glider, glider-
towplane, glider-GA, glider-fast-jet and glider-airliner and there is
no single technology or single product that well addresses all these
problems. The first thing in thinking about collision avoidance is to
be very clear just what problem(s) you are trying to solve.

I agree that Flarm and (and in the USA the flarm-flarm part of
PowerFLARM product) can be a significant help in glide-glider and
glider-towplane collision scenarios and I agree that the collision
with an airliner is a horrible scenario, for the innocent passengers
and crew, and would cause incredible damage to our sport. However
unfortunately this post seems to jumble up too much of all this
collision avoidance/traffic awareness technology and the capabilities
and benefits and that worries me.

The post talks about "flarm" helping with airliner collision avoidance
and that is a dangerous claim to make without some careful
qualification and is certainly not true with with the traditional
flarm product in Europe. Flarm (the flarm-flarm protocol) has nothing
to do with avoiding airliner collisions. Airliners and fast jets (and
most GA traffic outside of say tow planes) just will not be able to
receive or transmit the flarm protocol and the flarm protocol does not
make a glider visible to ATC.

The PowerFLARM product with 1090ES can receiver ADS-B over 1090ES.
Most airliners, fast jets and GA aircraft are not yet equipped with
1090ES data out. Rule for ADS-B equipage vary between Europe and the
USA, all airliners eventually will have 1090ES data-out but I don't
think anybody has good timelines yet for when a significant fraction
of them will be equipped. Once 1090ES data-out equipped a PowerFLARM
would "see" that traffic via 1090ES. The PowerFLARM will "see"
airliner traffic today via PCAS but obviously not get direction
information and PCAS tends to operate at relatively short range for
the fast closure rates involved in a collison with an airliner or fast-
jet. In general it really is a bad idea to think gliders are going to
operate in areas of high-density airline or fast-jet traffic and rely
on PCAS or ADS-B receivers to help provide avoid mid-air collisions.
The closure rates are high, gliders are often invisible to ATC primary
radar, and gliders are incredibly hard to see for those flight crews
even if they are aware/expecting the glider traffic.

In the USA and Europe effectively all airliners, many fast-jets and
many military transpots etc. are TCAS equipped, and many of that is
TCAS II. TCAS II provides those flight crew with mandatory climb/
descent instruction to avoid collisions. These instructions must be
followed and override ATC instructions to the pilot. Flarm and
PowerFLARM do not provide any visibility to TCAS and a TCAS equipped
airliner or fast jet will plow right through a glider equipped with
Flarm or PowerFLARM with no warning. *A Mode C or Mode S transponder
is the only device that both provide visibility to ATC radar and to
TCAS systems (and also TAS/TCAD and PCAS systems).

For all these reasons it is important for areas of high density
airline and fast-jet traffic that glider pilots continue to consider
equipping with transponders. It will will be concerning in those area
if say PowerFLARM is seen by some pilots as simple alternative to
transponder adaption.

The post also compares PCAS to Flarm. Many pilots in the USA use PCAS
for awareness of GA traffic and that is not addressed by traditional
Flarm units. The PowerFLARM is interesting in it does includes PCAS
capabilities.

The PCAS and 1090ES receiver capability of the PowerFLARM make it very
interesting to combine with a Mode S transponder with 1090ES data out
capability (like the Trig TT21) and that provides a solution that does
address a wide range of collision scenario. But in the USA even that
system will have issues at times inter-operating with UAT systems in
the dual-line ADS-B system in the USA (e.g. the issues with operating
outside of GBT coverage that I've described before in this thread).

---

I would also be careful claiming Flarm would prevent specific
accidents without a careful analysis. Especially because it is
unlikely that many GA aircraft will equip with a Flarm or PowerFLARM
device. So I'm not sure I claim absolutely that this would prevent the
Colorado mid-air with a Cirrus. PowerFLARM in the glider and tow plane
may have detected the Cirrus via PCAS, the Cirrus transponder may have
been interrogated enough to provide a PCAS alert but you have issues
of PCAS accuracy and false alarms especially if either or both the tow-
plane or glider have transponders. And I am not aware of what if any
traffic awareness system the Cirrus had on board. I not sure Flarm or
PowerFLARM are really relevant to the Hudson river collision, as those
aircraft are just not likely to equip with either product. It is more
likely in future that those aircraft would equip with GA oriented PCAS
or ADS-B data-out and data-in products, if they were both suitably
equipped in future then yes, hopefully that would reduce the chance
for such a collision. PCAS itself may be problematic is some areas
like this because of the high traffic density and high alarm rates.

Darryl- Hide quoted text -

- Show quoted text -

One thing to note for those already using a PCAS is that the
PowerFlarm can replace your PCAS unit, so you can save few hundred
bucks by selling your PCAS unit on Ebay. I am curious to know how the
PowerFlarm performs as a PCAS vs the ZAON MRX. While the MRX
definitely detects more aircrafts than our eyes, I often find the
audio alert does not give early enough warnings. Was any comparison
done between the units?

While I believe almost all of us (except maybe Mike) are sold on the
PowerFlarm, and I am definitely going to buy one, *it will be good to
show some statistics of how effective the Flarm was so far in reducing
mid airs, in particular, if any midair occured between 2 gliders
equipped with operaional flarms.

Assuming the PowerFlarm will be available really soon (anyone knows
when?), and based on the feedbacks we heard so far from pilots using
it in contests, *I can hardly imagine that anyone will want to fly in
a contest again without one after the chain of midairs we had
recently. I hope it will be mandatory, but to make it mandatory no
doubt the SSA should be able to rent them first, at least for the
first year or so, as I am sure everyone will want to buy one after
renting it once. At this rate I expect with some peer pressure most
pilots will be equiped with Flarms soon, those who don't will have
hard time sharing the sky with their buddies.

And last, I am not sure why the claim that GA pilots are not going to
adopt the PowerFlarm. They also suffer from midairs, and most of them
can efford it as well. I believe the ZAON MRX is quiet popular among
GA pilots as well, so I would expect the same to be true with
PowerFlarm which can replace the MRX and cost only $1K or so more.

Ramy

I do worry that the SSA does not bog down worrying about things like
renting units. The most important thing to do is make a clean decision
asap and let affected people know. I do not think there is a need to
prove the underlying FLARM technology works and you just need to look
here for pilots willing to open their wallets and start the ball
rolling. By all means allow others to rent out or loan systems, and I
am confident that will happen given a clean decision requiring devices
in contests. I worry it is easy to over complicate some of these
decisons that should really be driven by a safety/risk analysis as
long as the cost is reasonable and it looks at least to me like it
is.

The broader GA community will not adopt PowerFLARM for the flap
protocol - most of them won't worry about other flarm traffic. Pilots
wanting an ADS-B receiver might adopt the PowerFLARM but I suspect
many more will adopt devices more tailored for the GA cockpit, like in
the mid-range the recently announced Trig 1090ES receiver (e.g. it has
compatibility with popular GA fixed and portable traffic displays that
the PowerFLARM does not provide). At the low-end of the GA marked I'd
also wait and see what other products companies like Zaon bring to
market. I expect to see more ADS-B products aimed at the GA market -
but none will meet the needs that PowerFLARM does for us. While ADS-B
receivers will be interesting to GA pilots, the other pressure on GA
is going to be mandatory adoption of ADS-B transmitters and with the
pressure to spend money on that over the rest of this decade is going
to be interesting to see where pilots spend their avionics $$$.

Darryl

On Aug 11, 1:28*pm, Andrzej Kobus wrote:
Let's take a real life example. Last year I flew in Sports Nationals
in Elmira. I had PCAS with me. The first day after I released and
started climbing with a bunch of other gliders many of them equipped
with transponders I had to switch my PCAS off because of the quantity
of warnings. It was useless in that scenario.

Now, isn't a PowerFlarm unit a FLARM and PCAS in one box? Can I switch
off PCAS while leaving FLARM on when I am in a thermal with a bunch of
transponder equipped gliders so I don't get overwhelmed by warnings.
Once on task I could turn PCAS back on but in a congested thermal I
may not want to see it on.

Anyone knows how this situation would be handled by PowerFlarm?

This brings up a good question. Does the Powerflarm's collision
detection logic that is "tuned" for sailplanes apply to all input
(flarm, ads-b, mode c/s)?

If it is, no need to disable anything.

On Aug 11, 11:28*am, Andrzej Kobus wrote:

Anyone knows how this situation would be handled by PowerFlarm?

I hope that the PCAS function of PowerFLARM will either support target
specific alert suppression or will provide some other means of
eliminating nuissance transponder alerts. Without that it will be as
worthless as the ZAON MRX in a transponder rich glider environment.

There appears to be no public data on how the display or output data
stream will distinguish between targets detected by each supported
method. There also appears to be no public data on what alerting will
be provided for each target type. A lot seems to riding on the faith
that the other detection methods will be supported as well as the
FLARM targets.

As I said before the technical specs are very sparse and certainly not
complete enough yet for this engineer to spend $1.5k.

Andy

On Aug 11, 11:48*am, Westbender wrote:
On Aug 11, 1:28*pm, Andrzej Kobus wrote:

Let's take a real life example. Last year I flew in Sports Nationals
in Elmira. I had PCAS with me. The first day after I released and
started climbing with a bunch of other gliders many of them equipped
with transponders I had to switch my PCAS off because of the quantity
of warnings. It was useless in that scenario.

Now, isn't a PowerFlarm unit a FLARM and PCAS in one box? Can I switch
off PCAS while leaving FLARM on when I am in a thermal with a bunch of
transponder equipped gliders so I don't get overwhelmed by warnings.
Once on task I could turn PCAS back on but in a congested thermal I
may not want to see it on.

Anyone knows how this situation would be handled by PowerFlarm?

This brings up a good question. Does the Powerflarm's collision
detection logic that is "tuned" for sailplanes apply to all input
(flarm, ads-b, mode c/s)?

If it is, no need to disable anything.

It can't apply to PCAS (Mode C/S) because the PowerFLARM has no idea
of the direction of the threat, only the relative altitude and a
relatively crude estimate of the distance. There is also no way to
reliably use other tricks to correlate the threat's transponder with
an on-board flarm that you could do with say an ADS-B transmitter.
PCAS units have all traditionally had settings for alert volumes to
handle flying in different environments and pilot preferences and I'd
be very surprised if the PowerFLARM was any different but I have no
specific information on that.

I agree that ButterFly/FLARM would be better served with more
technical information, FAQs etc., including some tailored for the USA,
on their web site.

Darryl

On Aug 11, 11:42*am, Darryl Ramm wrote:


I do worry that the SSA does not bog down worrying about things like
renting units. The most important thing to do is make a clean decision
asap and let affected people know. I do not think there is a need to
prove the underlying FLARM technology works and you just need to look
here for pilots willing to open their wallets and start the ball
rolling. By all means allow others to rent out or loan systems, and I
am confident that will happen given a clean decision requiring devices
in contests. I worry it is easy to over complicate some of these
decisons that should really be driven by a safety/risk analysis as
long as the cost is reasonable and it looks at least to me like it
is.

The broader GA community will not adopt PowerFLARM for the flap
protocol - most of them won't worry about other flarm traffic. Pilots
wanting an ADS-B receiver might adopt the PowerFLARM but I suspect
many more will adopt devices more tailored for the GA cockpit, like in
the mid-range the recently announced Trig 1090ES receiver (e.g. it has
compatibility with popular GA fixed and portable traffic displays that
the PowerFLARM does not provide). At the low-end of the GA marked I'd
also wait and see what other products companies like Zaon bring to
market. I expect to see more ADS-B products aimed at the GA market -
but none will meet the needs that PowerFLARM does for us. *While ADS-B
receivers will be interesting to GA pilots, the other pressure on GA
is going to be mandatory adoption of ADS-B transmitters and with the
pressure to spend money on that over the rest of this decade is going
to be interesting to see where pilots spend their avionics $$$.

Darryl

Maybe I got lost in details, but I don't see much difference (except
the thermaling specific algorithms) between our needs and GA needs, at
least the slower "low end" GA which does not already use more
sofisticated traffic alert equipment than PCAS. If it is the best
solution for us, why isn't it for them? If they buy PCAS, why wouldn't
they buy PowerFlarm?
Also, are we making assumptions that we will be exempt from any future
GA mandatory adoptions again? It is not like we are posing less threat
than GA, on the contrary (less visible, less predictable and can be at
any altitude) and with all the recent attention we got I doubt we will
be exempt. As such, if we are willing to spend $$ on a temporary
solution which will undoubtly save some lives in the next 10 years or
so, why wouldn't GA?

Ramy

On 8/11/2010 12:15 PM, Ramy wrote:


Maybe I got lost in details, but I don't see much difference (except
the thermaling specific algorithms) between our needs and GA needs, at
least the slower "low end" GA which does not already use more
sofisticated traffic alert equipment than PCAS. If it is the best
solution for us, why isn't it for them? If they buy PCAS, why wouldn't
they buy PowerFlarm?


PowerFlarm may have fancy software to try to take into account that
gliders often do not fly straight. However, PowerFlarm certainly can
handle the simpler situation where planes do fly straight, and so I
would think Ramy is right -- PowerFlarm would be very useful to GA.

On Aug 11, 11:51*am, Andy wrote:
On Aug 11, 11:28*am, Andrzej Kobus wrote:

Anyone knows how this situation would be handled by PowerFlarm?

I hope that the PCAS function of PowerFLARM will either support target
specific alert suppression or will provide some other means of
eliminating nuissance transponder alerts. *Without that it will be as
worthless as the ZAON MRX in a transponder rich glider environment.

There appears to be no public data on how the display or output data
stream will distinguish between targets detected by each supported
method. *There also appears to be no public data on what alerting will
be provided for each target type. *A lot seems to riding on the faith
that the other detection methods will be supported as well as the
FLARM targets.

As I said before the technical specs are very sparse and certainly not
complete enough yet for this engineer to spend $1.5k.

Andy

Good points. Let's hope that the PowerFlarm dudes are reading this
discussion, taking notes and will provide some answers soon.

Ramy

It can't apply to PCAS (Mode C/S) because the PowerFLARM has no idea
of the direction of the threat, only the relative altitude and a
relatively crude estimate of the distance. There is also no way to
reliably use other tricks to correlate the threat's transponder with
an on-board flarm that you could do with say an ADS-B transmitter.
PCAS units have all traditionally had settings for alert volumes to
handle flying in different environments and pilot preferences and I'd
be very surprised if the PowerFLARM was any different but I have no
specific information on that.

- Show quoted text -

Ok, that changes things. Thanks for clarifying that for me.

Where I fly, it's very unlikely for any fellow flyers to adopt flarm.
If it could apply the same threat logic to non-flarm inputs I would
probably go for it. I've been on the verge of buying the MRX PCAS, but
I need to see more reason to spend the extra grand. I know it's more
"future-proof" than the MRX, but when does that pay off for my
sitation. Who knows. By the time ADS-B is in full swing, there may be
more cost-effective options for sailplanes.

Maybe I could buy a Powerflarm and rent it on occasion to the contest
guys. )

On Aug 11, 11:51*am, Andy wrote:
On Aug 11, 11:28*am, Andrzej Kobus wrote:

Anyone knows how this situation would be handled by PowerFlarm?

I hope that the PCAS function of PowerFLARM will either support target
specific alert suppression or will provide some other means of
eliminating nuissance transponder alerts. *Without that it will be as
worthless as the ZAON MRX in a transponder rich glider environment.

There appears to be no public data on how the display or output data
stream will distinguish between targets detected by each supported
method. *There also appears to be no public data on what alerting will
be provided for each target type. *A lot seems to riding on the faith
that the other detection methods will be supported as well as the
FLARM targets.

As I said before the technical specs are very sparse and certainly not
complete enough yet for this engineer to spend $1.5k.

Andy

Andy -- have some faith. The Flarm designers are glider pilots and
have been at this for years. The track record is that of remarkable
success. Even if it should happen that they screw up and don't put
separate volume functions in the initial release they are not going to
leave something stupid in the code for long. That would be a trivial
fix.

This engineer has ordered a unit!