Meeting to discuss FLARM in the USA

On 28 Oct, 05:51, Marc Ramsey wrote:
wrote:
Position and velocity vector is not sufficient information for a smart
collision alert,

What more information are you using besides position, pressure altitude,
and GPS-derived velocity vector to calculate a trajectory prediction?
If adequate information and processing power is available, than it
should not matter in the least whether the prediction is made by the
transmitter or receiver...

If his system is using aircraft performance as well, then for the
trajectory to be calculated by the receiver would either requi

1) aircraft type to be transmitted, and the receiver to have a
database of all possible performance parameters or

2) performance parameters to be transmitted with the other data

Both these have obvious (I think) disadvantages - it makes sense to me
to have th etransmitting aircraft say where it thinks it's going.

Ian

On Oct 27, 11:40 pm, Ian wrote:
On 26 Oct, 18:18, Ramy wrote:

On Oct 26, 9:07 am, Ian wrote:
SNIP

Anyway, my human eyes have successfully detected /all/ threats in time
to avoid them so far. How common are midair glider collisions?

Ian

How do you know what you have detected *all* threats in time. What
margin of safety is that down to? How do you know other aircraft (and/
or ATC) did not take action to avoid you and you were never aware of
them? I personally do not use logic like "my past landing attempt did
not kill me so my landings are great" but I look at what you are
saying as "I've not run into anything sofar therefore my visual
lookouts are perfectly adequate" - it is not a high threshold for
fidelity in this discussion, especially when you appreciate how much
the big sky is actually part of being responsible for you still being
alive. Do you routinely do clearing turns while cruising along to
clear all those large blind spots we have? How clear of clouds do you
really stay? How do you see fast traffic about to come out the cloud?
Have you ever seen how really hard it is to see a white glider closing
at over 100 knots head on against snow laden white mountainous
background?

Go fly in an aircraft with a TCAS or PCAS or similar and see how much
general traffic you don't spot until the system warns you to really
look or (carefully) turn the aircraft so you can see traffic. Flying
with a PCAS in my gliders has warned me a few times to start looking
intensely for traffic (much more than you would be able to do
continuously as a part of standard traffic scanning). The few closest
ones have been power traffic, in uncontrolled but high density traffic
areas some close and very oblivious to my glider being there at all.
From what I've seen the adoption of PCAS units like the Zaon MRX are
very viral. Lots of non believers until one or two glider pilots start
using them and then start reporting they really work, especially all
the traffic they otherwise would not notice...

Oh yes I've deliberately not stuck to Flarm, and I think Flarm would
be a very bad move for the USA. We need gliders in high traffic areas
with Transponders and PCAS today and ADS-B in future. Too many of us
fly in very high traffic areas, we need to be visible to and
communicating with power traffic and ATC as well as worrying about
glider-glider conflicts. Politically I am much more worried about a
glider taking out a passenger jet than I am about glider-glider
collisions. The last person who wanted to argue with me strongly that
mid-air collisions do not happen was flying with me in a Duo Discus
near Minden when not far away the ASG-29 met with a Hawker. Hell of a
way to win an argument.

Darryl

Is there any chance that you could adapt your FLARM system to conform to the
ADS-B specs in the US so that it would fit into the overall US airspace
strategy? That would make your device very interesting, not only to the
glider community, but also to the power aircraft market.

Mike Schumann

wrote in message
ups.com...
We should be able to attend the SSA convention in February.
If you wish we can make a presentation about FLARM.
We have no reservation whatsoever to sell FLARM in the US, legal
questions can be solved, but we would like to get positive feedback
from the US soaring community before doing so.

Some comments about the recent r.a.s. posts:

The frequency in all FLARM units can be set by software, therefore all
units work worldwide.
The transceiver is designed to meet FCC rules, but we have not yet
fully verified this.
It transmits at less than 1% duty cycle and (currently) 10mW.

"Nuisance alarms" versus "real alarms" will always be a hot topic for
any collision warning device in soaring.
1) We can and will further reduce "nuisance alarms" based on pilot
feedback and our own continuing research.
2) If the pilot "behaves well" in a gaggle he is much less likely to
suffer from "nuisance alarms" as the predicted trajectory will not
cross someone else's.
3) One of the unique features of FLARM is that each aircraft performs
and transmits its own trajectory prediction based on aircraft type,
flight path history and other parameters. This results in superior
system performance, especially in high density or heterogeneous
traffic environments.
It also safes a lot of processing power as each unit only needs to do
one sophisticated prediction and then just compares all received
trajectories to it.
Position and velocity vector is not sufficient information for a smart
collision alert, and don't get me started on the cheap "transponder
sniffer" devices... ;-)

Urs --- FLARM




--
Posted via a free Usenet account from http://www.teranews.com

On 28 Oct, 07:18, "
wrote:
On Oct 27, 11:40 pm, Ian wrote:

On 26 Oct, 18:18, Ramy wrote:

On Oct 26, 9:07 am, Ian wrote:
SNIP
Anyway, my human eyes have successfully detected /all/ threats in time
to avoid them so far. How common are midair glider collisions?

How do you know what you have detected *all* threats in time.

Because nobody has ever hit me. Therefore I and/or the other pilots
have /always/ managed to detect and deal with threats successfully.

What
margin of safety is that down to?

Can you define "margin of safety" in this case, please?

How do you know other aircraft (and/
or ATC) did not take action to avoid you and you were never aware of
them?

It doesn't really matter to me whether I successfully avoided them or
they successfully avoided me (that will almost certainly have happened
a lot, as I fly wood) - but I can say that "looking out" has always
worked for me. That's not to get complacent, of course, but I would
feel a lot happier if I knew that other pilots were not, to some
inevitable extent, relying on a magic gadget to lookout for them.

I personally do not use logic like "my past landing attempt did
not kill me so my landings are great" but I look at what you are
saying as "I've not run into anything sofar therefore my visual
lookouts are perfectly adequate"

How about "unless you buy a radio altimeter you will never be able to
plan an outlanding properly?"

Lots of non believers until one or two glider pilots start
using them and then start reporting they really work, especially all
the traffic they otherwise would not notice...

This is where I am sceptical. Yes, I am sure these things will give
lots of extra alerts - they'd hardly be worth buying if they didn't.
But we are not exactly plagued, world wide, by glider-glider
collisions, are we? So what this means is that pilots will spend a lot
more time reacting to false alarms (they must be false, because if
they weren't they'd end in a collision without the magic gadgets).

Do pilots have time available to do that? What are they not going to
do instead?

I can see a far stronger argument for using these things in areas
where other aircraft will not be looking out - Class A airspace, say,
or cloud flying, or scud running. But for normal flying ... colour me
unconvinced. That's only unconvinced yet, though. I'm not a complete
luddite. GPS sets are great - they may distract pilots' attention from
more important stuff, but not nearly as much as maps do. If flarm and
the like lead to a statistically significant reduction in the number
of midair collisions I'll be all for 'em.

Ian

Hi,

So what this means is that pilots will spend a lot more time reacting to
false alarms (they must be false, because if they weren't they'd end in a
collision without the magic gadgets).

I have been flying FLARM-equipped aircraft from my first introductory flight.

My reaction to a FLARM-alarm is simple: Check the direction (a quick glance at
the display mounted on the top of the glare shield) and map the target to
what I know is out there. In many more cases than I'd like to admit I find
an aircraft on a conflicting course that I simply had not seen before.

I MIGHT have found it myself once it got closer or manoevered, most propably
still in time to avoid a collision (If I did not believe that, I would not
be flying at all) but FLARM notified me earlier and so I reactions typically
are more relaxed. I do not consider FLARM firing in that situation a false
alarm, it is exactly what the gadget is intended for.

I also do not mind alarms when thermalling. When sharing a thermal with
well-matched aircraft and well-behaved pilots FLARM generally stays
quiet. If there is a repeated alarm from my six I tend to leave as this
means someone is flying behind me in a way that bothers the device and
that in turn bothers me. Never mind wether the threat is real or not.

The same is true in other alarm-situations. I have never had to mute the
thing because of an annoying repeated alarm from some target I knew about.
I simply avoid them by a wide enough margin. Not just to silence the alarm,
it feels like the right thing to do anyway and the FLARM-software seems to
think the same and shuts up.

There is no fiddling with FLARM as with other gadgets. It turns on when the
battery is connected and that's it. Sure you can toggle different modes, mute
it etc.. I never do. And if you do there just the single button to press.

The only thing I really don't like about it is when I'm down on the ground
and stopped and get a shrieking "impending death"-alarm because someone else
comes in over to land further down the field :-). Yes, if there were to
be a collision in that situation I might get out and dive for cover or
something :-), but still that is the one thing I would change about the
softwa Do not go off after the aircraft has come to a complete stop.

If flarm and the like lead to a statistically significant reduction in
the number of midair collisions I'll be all for 'em.

I firmly believe it does. I would prefer a solution that would also target
power traffic both commercial and recreational more than FLARM does (our
tow-plane has one of course :-)), but that does not mean I am not going to use
what's there.

I have not ever felt distracted by FLARM and think if there is any influence
on my lookout then it actually improves it.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn
http://www.marian-aldenhoevel.de
"Success is the happy feeling you get between the time you
do something and the time you tell a woman what you did."

Ian wrote:
On 28 Oct, 07:18, "
wrote:
On Oct 27, 11:40 pm, Ian wrote:

On 26 Oct, 18:18, Ramy wrote:
On Oct 26, 9:07 am, Ian wrote:
SNIP
Anyway, my human eyes have successfully detected /all/ threats in time
to avoid them so far. How common are midair glider collisions?

How do you know what you have detected *all* threats in time.

Because nobody has ever hit me. Therefore I and/or the other pilots
have /always/ managed to detect and deal with threats successfully.



What
margin of safety is that down to?

Can you define "margin of safety" in this case, please?

How do you know other aircraft (and/
or ATC) did not take action to avoid you and you were never aware of
them?

It doesn't really matter to me whether I successfully avoided them or
they successfully avoided me (that will almost certainly have happened
a lot, as I fly wood) - but I can say that "looking out" has always
worked for me. That's not to get complacent, of course, but I would
feel a lot happier if I knew that other pilots were not, to some
inevitable extent, relying on a magic gadget to lookout for them.

I personally do not use logic like "my past landing attempt did
not kill me so my landings are great" but I look at what you are
saying as "I've not run into anything sofar therefore my visual
lookouts are perfectly adequate"

How about "unless you buy a radio altimeter you will never be able to
plan an outlanding properly?"

Lots of non believers until one or two glider pilots start
using them and then start reporting they really work, especially all
the traffic they otherwise would not notice...

This is where I am sceptical. Yes, I am sure these things will give
lots of extra alerts - they'd hardly be worth buying if they didn't.
But we are not exactly plagued, world wide, by glider-glider
collisions, are we? So what this means is that pilots will spend a lot
more time reacting to false alarms (they must be false, because if
they weren't they'd end in a collision without the magic gadgets).

Don't let the fact that you have not had or realised that you have had a near
miss to date blind you to the risks. Even when everyone is being careful things
can, and do, go wrong. It is generally not the aircraft we saw that represent
the highest risk we have encountered. It is the ones we failed to observe.

In at least one situation I avoided a collision more by luck than judgement.

Regional contest - lots (20)of different performance gliders in the same
thermal. Me being the novice slowly getting the last out of the top of the
thermal - waiting for the gate to open. Fortunately someone on the other side of
the thermal saw an ASW20 flying perfectly synchronised, directly below me
getting way too close.

The ASW20 pilot did not see me around the brim of his hat. I could not see him,
even after the call. ('xxx' above you!) When he saw what he was doing he dived
away and left the thermal. I only realised it was me they were talking about
later - When we looked at the traces afterwards it was less than 5m vertical
separation...

If we had Flarm we would not have been in the situation of not knowing about
each other.

Do pilots have time available to do that? What are they not going to
do instead?

I can see a far stronger argument for using these things in areas
where other aircraft will not be looking out - Class A airspace, say,
or cloud flying, or scud running. But for normal flying ... colour me
unconvinced. That's only unconvinced yet, though. I'm not a complete
luddite. GPS sets are great - they may distract pilots' attention from
more important stuff, but not nearly as much as maps do. If flarm and
the like lead to a statistically significant reduction in the number
of midair collisions I'll be all for 'em.

Ian

Flarm is a tool - like all tools it is only as useful as the person using it
makes it. I have met at least one pilot who's over dependence on it makes him
dangerous - Most reasonable people will use it for what it is designed to be. An
aid to optimising their lookout. It is becoming steadily more common in South
African gliders and for that reason is becoming worth having.

Ian wrote:
On 26 Oct, 18:18, Ramy wrote:
On Oct 26, 9:07 am, Ian wrote:
SNIP

[1] and have no intention of doing so: I'm profoundly sceptical about
a further increase in the number of things to fiddle with and focus on
inside the glider. Why not just look out?
Because your human eyes can't detect most threats on time to avoid it,
especially gliders and especially if they are comming from behind or
the side.

The pilots of these gliders should be able to see me - if they are not
busy concentrating on yet another electronic gadget in the cockpit.

You haven't flown with a FLARM, yet you keep saying this. Why do you
think they are "concentrating" on FLARM? From what I've read about it,
and from what users say, there is no "concentrating": you go about your
flying until it alerts you.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

There are ca 9 000 FLARM units in use in Europe, and all who use them
seems to be in favour of it. There seems to be no FLARMs in the US, but
a lot of people who is against it.

When I bought my ASW 28-18E last winter it was already equipped with a
FLARM. I used to be against FLARM for all the reasons listed in this
thread, now that I have flown with it I am in favour of it.

Robert Danewid
ASW 28-18E RD

Ian wrote:
On 27 Oct, 17:08, pascal wrote:

It's always a shock when you pass a glider coming from
the front without having the warning (because it is not equipped with
flarm); and despite looking out you surprise yourself not having
noticed that particular glider.

I wonder how well you look (ie one looks) out when a little part of
the brain assumes that flarm would have reacted to anything that
mattered?

There is always the problem of adverse compensation when a safety device
is introduced. Monitoring of the situation should continue after the
introduction to ensure the desired increase in safety occurrs. I believe
this is the case with FLARM.

What puzzles me is how skeptical you are about a widely accepted device
you have not used. FLARM has sold 9000 units. 9000! When 9000 pilots
voluntarily equip their aircraft with an $800 device, I am inclined to
think there may be something quite useful there and to look forward to
an opportunity to use one.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly
* "Transponders in Sailplanes" http://tinyurl.com/y739x4
* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

Ian wrote:
On 28 Oct, 05:51, Marc Ramsey wrote:
wrote:
Position and velocity vector is not sufficient information for a smart
collision alert,
What more information are you using besides position, pressure altitude,
and GPS-derived velocity vector to calculate a trajectory prediction?
If adequate information and processing power is available, than it
should not matter in the least whether the prediction is made by the
transmitter or receiver...

If his system is using aircraft performance as well, then for the
trajectory to be calculated by the receiver would either requi

1) aircraft type to be transmitted, and the receiver to have a
database of all possible performance parameters or

2) performance parameters to be transmitted with the other data

Both these have obvious (I think) disadvantages - it makes sense to me
to have th etransmitting aircraft say where it thinks it's going.

I can't see the need to transmit anything more than the aircraft
category and 3D velocity vector (which are both transmitted in the ADS-B
message), as what matters is what the aircraft is likely to be doing in
the next few seconds, not what it could do given a longer period of time.

Marc