PowerFLARM leeching comments

On Oct 18, 1:19*pm, Mike the Strike wrote:
I'm with Dave on this one. *Even though we have seen competitors zoom off towards a PowerFlarm target they saw climbing strongly, I am not sure this will turn out to be the advantage many wish for. *I can't count the times I have ended up a thousand feet or so below a colleague climbing at ten knots to find nothing there - the thermal bubble had departed upwards!

My opinion is that knowing the location of nearby competitors is useful for both safety and tactics, but will impart no advantage if the information is available to everyone. *I strongly oppose the adoption of the "stealth' mode for this reason.

Mike

My view: There are two basic questions about flarm leeching:

1) Does it work, really, in practice? As others have mentioned,
information more than a few miles away is pretty useless. I can see
some help in keeping teams together, and the comments on uvalde blogs
bear that out. But if you can't see the glider, it's not obvious that
going to its thermal is going to help.

2) If it does work, do pilots like or dislike the change in the racing
experience? The answer from Europe seems to be "like." We have not
heard a chorus of "flarm leeching is ruining the sport" though
they've been at it 10 years. We have heard a bunch of "I miss the AST
when you knew where people were," and perhaps flarm displays will
bring back some of this experience.

Still, our (US) ratio of theory to experience on both issues --
especially the second -- strikes me as pretty large at the moment.
Next year will be an interesting racing season.

John Cochrane

On Thursday, October 18, 2012 2:37:27 PM UTC-4, John Cochrane wrote:
... our (US) ratio of theory to experience on both issues --
especially the second -- strikes me as pretty large at the moment.

Make that "Rampant Aviation Speculation" grossly exceeds "actual knowledge"...

Just to be clear ;-)

See ya, Dave

In the first seasons of competition flying with FLARM in Germany a few people were turning on stealth mode, especially if they did not have a display to get any tactical data. Turning FLARM off was also observed regularly. Now I hardly notice anyone using stealth mode anymore. The initial fear of having a competitive disadvantage seems to have run dry.

Flarm is far from giving you a clear picture of the thermals ahead. On average the range is smaller than the distance you can see with your eyes, so your best bet for finding a thermal is still looking outside. There are occasions where Flarm brings another glider to your attention you would otherwise have missed but it is far from being a reliable thermal finder.

FLARM range is extremely variable. I fly a lot of club gliders with different antenna installations and I have seen gliders with carbon fuselage with hardly 2km of reliable range for collision avoidance. Especially to the rear a carbon fuselage will often completely block the Flarm signal so that a target flying right behind you will sometimes not be visible. In other cases I have had peak ranges up to 25km which usually only last long enough to display the target for a few seconds. A very good installation should give you fairly reliable contacts up to 4 - 6km and irregular peaks of up to 8-16km. Remember that the range always depends on antenna installation in both gliders. Even with a perfect installation you will not see some Flarm equipped gliders even on short range.

Flarm will give you some benefits in competition flying. Besides the advantages mentioned above it is particularly good for tracking what is happening around. You can marker specific targets to keep track of your team mate or see your progress against a selected competitor. It’s not like the range and reliability is good enough to leech someone outside your eyesight but you get an occasional fix of your marked competitor a few km ahead (or behind) giving you some sense of whether you are gaining or losing ground. Personally I enjoy this because it makes gauging my own performance a little bit easier.

The most useful feature of Flarm is still collision avoidance. You get a really good situational awareness of what is happening around you. Bad surprises of a glider appearing out of nowhere, hardly happen anymore.

On Thursday, October 18, 2012 2:20:25 PM UTC-7, Alexander Swagemakers wrote:
In the first seasons of competition flying with FLARM in Germany a few people were turning on stealth mode, especially if they did not have a display to get any tactical data. Turning FLARM off was also observed regularly. Now I hardly notice anyone using stealth mode anymore. The initial fear of having a competitive disadvantage seems to have run dry.



Flarm is far from giving you a clear picture of the thermals ahead. On average the range is smaller than the distance you can see with your eyes, so your best bet for finding a thermal is still looking outside. There are occasions where Flarm brings another glider to your attention you would otherwise have missed but it is far from being a reliable thermal finder.



FLARM range is extremely variable. I fly a lot of club gliders with different antenna installations and I have seen gliders with carbon fuselage with hardly 2km of reliable range for collision avoidance. Especially to the rear a carbon fuselage will often completely block the Flarm signal so that a target flying right behind you will sometimes not be visible. In other cases I have had peak ranges up to 25km which usually only last long enough to display the target for a few seconds. A very good installation should give you fairly reliable contacts up to 4 - 6km and irregular peaks of up to 8-16km. Remember that the range always depends on antenna installation in both gliders. Even with a perfect installation you will not see some Flarm equipped gliders even on short range.



Flarm will give you some benefits in competition flying. Besides the advantages mentioned above it is particularly good for tracking what is happening around. You can marker specific targets to keep track of your team mate or see your progress against a selected competitor. It’s not like the range and reliability is good enough to leech someone outside your eyesight but you get an occasional fix of your marked competitor a few km ahead (or behind) giving you some sense of whether you are gaining or losing ground. Personally I enjoy this because it makes gauging my own performance a little bit easier.



The most useful feature of Flarm is still collision avoidance. You get a really good situational awareness of what is happening around you. Bad surprises of a glider appearing out of nowhere, hardly happen anymore.

This is consistent with my experience over 7 days of contest flying with PF.. It is occasionally modestly helpful out on course in keeping track of competitors who are within a few miles of you. I found four specific instances where it was helpful:

1) Running down a group of pilots who started a couple of minutes ahead of me. On a blue day in particular, getting the right first climb can save a couple of minutes by keep you in touch with markers a bit better. On one occasion I was able to close on a group of very good pilots by about 2-3 minutes over the first 30-40 miles. They were just outside of visual range most of the time, so PF made a difference.

2) Calling attention to where there might be a good climb ahead - this was most often useful when making long-ish glides between areas of lift. With a big enough field of competitors, depending on the course, you randomly end up with situations where you'll pick up someone climbing in front of you - for me it happens a couple of miles before the naked eye can make the target out. It's possible that you might pick them up anyway, but just knowing where to point the nose to find a climb at the end of a long glide was modestly helpful and worked for me a couple of times.

3) Choosing a direction coming out of a turnpoint. Gliders collect at turpoints so I occasionally had a couple of targets out in front of me at turns. Should I take the deviation out to the cloud street or head straight down the courseline? I found myself using trends in altitude differential over several minutes to gauge climb much more than the PF transmitted climb rate, which is too noisy to be useful beyond "climbing or not?" questions.

4) Marking my progress against known competitors. I wrote down the PF codes for specific competitors as I became aware of them. On a couple of occasions on long legs I made different courseline decisions from other pilots and was able to mark progress as they came back into range dozens of miles later - this didn't really yield useful tactical information, but it made me feel good to come back in range with a rival having made some ground on them.. Discovering the opposite is a bit disheartening, but motivating.

I'd say in total it made maybe 1% difference in total points over a contest, though I'll never know for sure if it saved me from flying into a hole or led me astray in specific situations. A bigger search radius for other gliders out on course certainly doesn't hurt and I found it increased my enjoyment by making racing slightly less solitary.

Most importantly, PF called my attention to a handful of collision targets that I am certain I would never have seen without it. It's sobering to realize how many potential midairs in the past must've been avoided by nothing more than random chance.

9B

At 18:19 18 October 2012, Mike the Strike wrote:
I'm with Dave on this one. Even though we have seen competitors zoom off
t=
owards a PowerFlarm target they saw climbing strongly, I am not sure this
w=
ill turn out to be the advantage many wish for. I can't count the times
I
=
have ended up a thousand feet or so below a colleague climbing at ten
knots=
to find nothing there - the thermal bubble had departed upwards!

My opinion is that knowing the location of nearby competitors is useful
for=
both safety and tactics, but will impart no advantage if the information
i=
s available to everyone. I strongly oppose the adoption of the "stealth'
m=
ode for this reason.

Mike

We did have a period of about 2 years where competition directors were
"instructed" to mandate stealth mode. Despite this I never did for the very
simple reason that I was very uncomfortable with the concept of instructing
pilots to lessen the efficiency of an anti-colision assistance device.
While we do not have the same "litigate everything" culture that exists
elsewhere I could see some grieving relative making a claim on me for
contributing to the death of their loved one by lessening safety, unlikely
maybe but that is the way things are going even here in the UK.
It is just not possible to uninvent something and rest assured, like
artificial horizons on iPhones, someone will make and install a gizzmo just
to give them an advantage and it will be cheaper than FLARM. The only way
forward is to accept that such things are going to be used whatever you do
so the only sensible way is to not mandate against it,

On Saturday, October 20, 2012 5:30:05 PM UTC-4, Don Johnstone wrote:
... I was very uncomfortable with the concept of instructing
pilots to lessen the efficiency of an anti-colision assistance device.

Stealth mode in no way lessens the efficacy of FLARM anti-collision.
It gives you warnings when there is a collision hazard regardless.

Hope that is clear,
Best Regards, Dave

Exactly! Furthermore, the only thing happening when you set up stealth mode
is that you are sending a special information, together with your traffic
info through the radio, saying "I want stealth mode".
Other Flarms receiving this information with your traffic data will not send
out to the data port the complete data as usual.
Instead, they will work it out to make them somehow "unusable" for data
mining scope.
But the core flarm is receiving all info, and it is processing it as usual
concerning alerts and safety.
An intelligent approach in my opinion, because when you are close to the
traffic danger, the information is passed to data port integrally.
So nothing happens around safety.
Everything is about data outgoing to external instruments.

However in my opinion the stealth mode is not enough "strong" for the
purpose.
For example, the altitude is scrambled with sort of a white noise,
numerically, but averaging the value will most likely return the real
altitude to programmers.

There is another aspect about leeching with traffic advisors: range.
Range is fundamental if you want information about what is going on ahead of
you, say 10km away, 20km away.
First you need to extend the "range" flarm should use while sending out to
data port traffic info.
This can be done programmatically by the external instrument (LK offers a
button to do it).
But then, you actually need to be able to receive the radio transmission,
which is weak at 10mw if I remember correctly.
Those of use who are radio entusiasts know too well that the antenna makes
the big difference !
A good antenna will catch weak signals, and let you know what's happening
far away.
The standard antenna will not.
The antenna is attached with a standard SMA connector, and for 10 dollars
you get so many antennas to choose from!

So here is an example of what you can obtain from LK software, and probably
other (not sure):
- you sort the traffic by direction ahead of you, and you see the lift
values, suppose at 20km distance: a thermal ahead of you.
- you are about to leave you thermal and decide to go for the next one,
under that big cumulus.
- you know the lift value under there, and the exact position for best lift.
- you select the traffic position and make it a virtual waypoint, and you
immediately know the MC you can use to get there.
- You start the fast glide over there, and when you approach the cumulus
there are no more gliders under it, but you still get their traces drawn in
green red blue on the map, so you know exactly where to pull up.

It is also possible to calculate the MC value someone is flying with,
knowing the aircraft type (and thus its polar).

paolo




"Dave Nadler" wrote in message
...

On Saturday, October 20, 2012 5:30:05 PM UTC-4, Don Johnstone wrote:
... I was very uncomfortable with the concept of instructing
pilots to lessen the efficiency of an anti-colision assistance device.

Stealth mode in no way lessens the efficacy of FLARM anti-collision.
It gives you warnings when there is a collision hazard regardless.

Hope that is clear,
Best Regards, Dave

On Saturday, October 20, 2012 5:52:55 PM UTC-4, Dave Nadler wrote:
On Saturday, October 20, 2012 5:30:05 PM UTC-4, Don Johnstone wrote:

... I was very uncomfortable with the concept of instructing

pilots to lessen the efficiency of an anti-colision assistance device.



Stealth mode in no way lessens the efficacy of FLARM anti-collision.

It gives you warnings when there is a collision hazard regardless.



Hope that is clear,

Best Regards, Dave

Dave,

it is clear, and while your statement is probably technically accurate, it isn't entirely correct. Any mode that reduces the pilot's situational awareness also degrades safety to some extent. Stealth mode by definition does exactly that. The OC fatality scenario is a case where stealth mode might not provide enough warning to assess the situation and take appropriate action, whereas the 'full' mode probably would. Just my $0.02

Frank (TA)

On Oct 18, 10:23*am, Dave Nadler wrote:
On Wednesday, October 17, 2012 9:35:12 PM UTC-4, Craig R. wrote:
Time to state the obvious.

It sure is.

If you aren't very close to other gliders, you're
not going to be able to leech.

How long does a thermal last ?
Not very long, and likely weak or gone when you arrive.

Will they be at your altitude when you arrive ?
Nope.

Keeping track of where other gliders went ?
Maybe, but only at short range.

Leeching ?
Not particularly helpful.

Try following a good pilot sometime, from an even position.
See how many minutes it takes for him to loose you.
Won't take long, even if you start dead even.
Especially if your head is in the cockpit playing video games.

Consequently, in Europe, "stealth mode" has proven an
irrelevant annoyance and is largely abandoned in practice.
At WGC, nobody bothered with this.

As ever, look out the cockpit for the best clues !

Hope that's helpful,
See ya, Dave

Dave,

Well said. The thought of PF as a "leeching" tool never entered my
brain.............I'm surprised some are terrified it might erode
whatever lead they may feel they have over their fellow pilots.

Brad

On Wednesday, October 17, 2012 9:35:12 PM UTC-4, Craig R. wrote:
Time to state the obvious. After reading the comments in many of the recent PowerFLARM threads, many folks want to use PowerFLARM for “leeching”.. Many are asking for programs to expand and simplify the use of that data. While that information is a byproduct of the important aspect of PF collision avoidance data, I think it has hidden issues. I understand that many folks just want to say they flew X miles on today’s flight (local bragging rights or OLC standings come to mind). If they get the flight data from someone else, that is just dandy. It certainly is easier. Instead of learning from the mistakes they made and trying to improve their skills, they won’t learn and won’t improve. Unfortunately, this may give them confidence in skills they really don’t have and perhaps put them in situations they shouldn’t be in. They will just grouse that their PF reception is substandard, they couldn’t see that glider 6 nm out and what lift they were in and missed that great thermal that shortened their day.... Personally, I would prefer to look back on my flight and know that I read the terrain and weather conditions properly and made the most of the day. I can analyze my flight and know where I had issues and learn from my mistakes. I can kick myself when necessary and move on. The challenge for me is to see how well I do without any “hand holding”. Hopefully, my skills will improve and I will fly faster and farther the next time. Obviously, I’m setting myself up for major flaming here (GPS, computers, programming, etc will be brought up). However, none of those tell me which specific spot to fly to on course for a 700 fpm thermal and puts that exact location on my moving map. Only a radio call from the person in that thermal approximates that and that data is not as accurate as the PF readout. Generic radio calls happen so infrequently that it isn’t an issue (team flying may or may not give that data, depending on your partner and your relative position - and how many really team fly?). With the PF data, some of that inaccuracy goes away. Certainly, you won’t use this information on every thermal throughout the day, but 3 or 4 spotted thermals can be the difference between an average day and a very good day. Will this data go away or will people stop using it in this format? Of course not. However, I would like to see people consciously use the PF data for collision avoidance and ignore the leeching aspects. Pilots that continue to learn and improve are better and safer. That is good for everyone. I know that “ain’t going to happen” so stealth mode FTW ;-) Craig R.