If You've Flown a FLARM Stealth Contest, Vote Here

I flew at Harris Hill and I am not a fan of Stealth Mode for all the reasons that Andy Blackburn and John Cochrane have posted, as well as for the reasons that Jerzy has posted.

At Harris Hill, I helped several other pilots configure their Flarm to Stealth mode, I know how it is done, yet my Flarm never produced an IGC file that showed Stealth was on. I downloaded dump files and they showed the Priv mode flag had been set, yet the IGC file showed it wasn't.

I wasted time trying to set Stealth mode and finally gave up after many futile attempts.

As has already been posted, another pilot elected to land during the HH contest when he noticed before the start that his Flarm had switched out of Stealth mode from the previous contest days. This resulted in a less than ideal start for him.

For all of these reasons, I am not a fan and I truly hope the RC does not mandate Stealth, or if they do, that all Contest organizers ask for a waiver to remove the Stealth restriction for their contests.

On Sunday, December 6, 2015 at 6:08:32 PM UTC-8, wrote:
On Sunday, December 6, 2015 at 2:46:16 PM UTC-5, jfitch wrote:
Your soaring ideal is frozen at 1975 levels.
SNIP
The sport has changed from the times of Lilienthal. There will always be those who resist change and those who embrace it, but change is relentless and due to participant turnover almost always wins.

(sigh) So...to my earlier lament about being "misquoted" and "misinterpreted", I can now add "gratuitously insulted." Argh. I'm tempted to ignore Jon's torturous tirade but on the off chance that someone might actually believe it, I'll try again.

Soaring attracts different people for different reasons. That's cool. Though not a top pilot myself, I am inspired by the opportunity to fly with them to do more than I might otherwise do. That's part of the appeal of competition. But safety is paramount, and not just for me. As a task advisor, I've occasionally recommended against tasks that arguably could have been flown by a few pilots because I didn't feel comfortable with them for much of the field.

I like the challenge of mastering a difficult sport, my fears, and the associated risks. If it were easy, anyone could do it. But I don't like scaring myself...or others. Certainly I don't want new contest pilots to be scared; I want them to get excited, the way I have been for so long, when they discover they can manage the risks that worry them with a huge sense of accomplishment.

So I don't take chances with their lives or mine. When I was starting out, my father made me repeat a mantra before every contest flight that I still adhere to: first comes personal safety, then safety of the glider, then contest points. That's why I borrowed and then bought FLARM this year even though it wasn't required. It helped mitigate what I perceive as the most serious risk for me: i.e., midair collision. And it has done that, in both open and stealth modes.

That said, for perfect safety, there's only one solution: not to fly. Everything else represents balancing risk with cost and reward. I don't plan to stop flying yet, Jon, but if you truly have the courage of your convictions about no compromises on safety, feel free. It would be a shame to lose you, though. Soaring needs all kinds.

I'm not living in the past (though 1975 wasn't a bad year). I haven't upgraded gliders from the "trailing edge of glider technology" [did you make that up?] because I don't feel like increasing my already substantial investment. And I don't have to. I can compete in any of three different classes on a straight up basis. And the FAI combined Std./15M class for antideluvian primary gliders is fun, too.

I'm not opposed to change, just change for its own sake--just like I caution clients against technology for its own sake even though technology is my business.

On the subject of pellet varios, I don't know how long ago 1975 seems to you but I assure you they were out of serious competition cockpits well before then! Hahaha. I don't even have fond memories. They typically weren't total energy compensated and they had a tendency to stick when it got humid.

Take a deep breath. Elmira was an experiment and a success. We'll learn more at Nephi. We may decide to return to open FLARM. We may even learn things that will help us deal intelligently and fairly (as opposed to loudly and acrimoniously, not that I'm pointing fingers) with the continuing evolution of ADS-B and other technologies in our sport.

I think it's ironic that, given the past few years of history we've built up with FLARM here in the U.S., I'm being accused of not wanting to change.. It strikes me that those who want to freeze FLARM the way it's been here rather than explore another aspect of it are the inflexible ones.

Chip Bearden
ASW 24 "JB"
U.S.A.

Chip, we just have different ideas about what soaring should be. By your own admission, you opposed GPS because it changed the sport by removing some navigational tasks. You are also opposed to the situational awareness that Flarm brings, as it also changes the sport. I view both of these things as desirable changes, you do not. Neither position can be proven objectively correct, they are opinions. Nevertheless I believe these changes will occur regardless of what we think. They are already ubiquitous in touring type soaring, and to make racing an increasingly isolated corner of a decreasingly popular sport seems unwise if it is to survive.

I thought you would like my characterization of "standard and 15m" as the trailing edge . But they are old designs. The industry and sport is moving, including the electronics in the panel. Maybe racing needs to move too.

In my time flying glider competitions we have had several electronic "demons" tried and exectuted with extreme prejudice. The first demon was a smartphone (since restored). Then it was XC soar having a 1cm artificial horizon field, and the spectre of rampant cloud flying because of it. The potential of accessing weather data in flight has been protested too. Now, the latest "demon" is POWERFlarms BASIC ability to improve situational awareness for other gliders within, say, a few miles (at best) and rampant FLARM "leeching." The solution, stealth mode (almost completely untested) is clearly coming to save those who have apparently been losing points because of this "vulnerability." It still seems rather far fetched to me.

Here comes another thing to do when going to a contest. Great! I also hear stealth mode doesn't work very well and that a new comfiguration is coming that may improve safety gaps. Is a new configuration of stealth mode on its way? Does it really work? Is it being tested? Does it compromise FLARM safety in any way? I have not really heard definitive answers to any of this.

I fly with an SN10 and a tiny Flarmview display which is almost useless. Maybe I need a clearnav or LX9000 to understand all the hubbub regarding Flarm leaching. I don't think it's as big of a deal as its being made out to be, and I honestly don't really think the data is very usable tactically. I will say that it is sometimes nice to know (for example) if you've gained or lost on a competitor to be honest. For me, moments like these are often the only times it feels like we are racing. (Last thermal was 1000 above and now I'm 2000, cool, I've gained, for example). But the truth is that I almost always see that out the window before any Flarm data confirms it. I honestly dislike looking inside of the cockpit at all.

I have rarely, if ever, referred to my Flarm display tactically unless there is an audible warning and I want to cross check where a glider is when I thought I was alone (for example). But maybe Flarm data is more powerful when you have a sophisticated flight computer display that allows more information to be displayed on the map view as you search for gliders (to leach) ahead? I also cannot imagine who has the time to screw around like that with the Flarm while competing. Another thing I notice often is that if you are behind a carbon glider, even 100ft, you won't see them on Flarm as their signal is entirely blocked. At a mile or more, no way are you going to see data, and so on.

When I was at the PAGC, I didn't have time to look at the Flarm for out of visual range targets, ever. Only when the Flarm beeped did I notice any targets always at close range. Maybe I missed the memo here? Maybe my antenna is wrong. My teammate (clearnav I think) did notice a glider ahead, once, and I could not see them visually even knowing their O clock and relative altitude. It was somewhat valuable that one time, yes. But he and I did not use the Flarm to chose our routes on a regular or remotely regular basis. In fact, I don't believe we ever did. I simply don't understand how team flying encourages Flarm leaching any more or less than individual flying either. Or how FAI rules encourages or doesn't encourage Flarm leaching vs US rules.

For those who are saying they "like" stealth mode here (or don't)...are you saying you like that you can't Flarm leach anymore or are you assuming that you were no longer being leeched because of it? Do we have any data? Examples? Did someone suspected of exploiting "Flarm leaching" who normally does really well fall down the standings? Did anyone demand normal Flarm mode be reinstated? ;-) Is there any serious evidence or proof that Flarm leeching is occurring and has regularly benefited someone? There should be some evidence of a change in performance when stealth mode is used, should there not? And these patterns should be identifiable in flight data.

I honestly really don't care what mode is used but overall, the supposed problem feels a little over dramatic. I don't think it will make a big difference. Perhaps I am wrong. The good news is I can keep flying happily with my SN10 as the Flarm leeching "picture" offered by the modern computers was one of the potential reasons to consider buying something more sophisticated. Now, that feature doesn't appear to matter as much, if at all. So, mainly for that reason, I fully support "Stealth mode!"

7T

Excellent point. This smells rather rushed and "uncooked." If it was a development project from my team I would be concerned. One US contest late in the 2015 season and now the RC is already seriously considering a major change even before Flarm is mandatory accross all US contests or close to fully adopted. I think a year of careful testing (at least) is smart. The risk of a stealth mode "collision" still far outweighs the risk of a pilot getting a free thermal.

Perhaps FLARM et all (BGA, IGC, etc) should make a detailed statement to the public about the testing and development program underway for stealth mode and exact expextations/ requirements for safety and performance of collision alerts that are being worked towards.

This feels a lot like a synthetic vision avionics supplier doing an install and saying "go flying" in heavy IFR. It will be fine...

On Monday, December 7, 2015 at 9:50:51 AM UTC-5, Sean Fidler wrote:
Excellent point. This smells rather rushed and "uncooked." If it was a development project from my team I would be concerned. One US contest late in the 2015 season and now the RC is already seriously considering a major change even before Flarm is mandatory accross all US contests or close to fully adopted. I think a year of careful testing (at least) is smart. The risk of a stealth mode "collision" still far outweighs the risk of a pilot getting a free thermal.

Perhaps FLARM et all (BGA, IGC, etc) should make a detailed statement to the public about the testing and development program underway for stealth mode and exact expextations/ requirements for safety and performance of collision alerts that are being worked towards.

This feels a lot like a synthetic vision avionics supplier doing an install and saying "go flying" in heavy IFR. It will be fine...

As requested- a year old, provided by Russell Cheatham. More development on the topic before long.
Text of the paper follows
UH

Flarm and the case for modified "Stealth" protocol
What's the problem
Range of Flarm now gives competitors the opportunity of identifying, locating and assessing the climb rate of competitors over 20km away. This has evolved with the production of better Flarm electronics (Powerflarm) and a better understanding of influence and importance of antenna location and design. Whilst the improved performance is most welcome as it now ensures that all installations are seeing and being seen at the important 2km range with much reduced blind spots(2km required for effective collision avoidance head to head), it has dramatically increased the tactical use by competition pilots.
Tactical benefits on task include being able to assess climb rate of others and identify where important pilots are in order to make improved strategic decisions. Even if the targets in view are not "tagged" they give important information for gliders behind to optimise routing and to ensure that if required a follower may ensure they fly the same route. Tactical benefit prior to start is even greater as it allows a full view of the start line area so it is clear where all the start gaggles are located, where key competitors are, whether they have started and sometimes what rate of climb is achieved in the first thermal on task.
It is arguable whether this sort of tactical assistance diminishes the art of racing gliders. I believe it does but this is not the main thrust of this paper. Flarm in isolation is a great safety device that has rightly been encouraged to the position we find ourselves today where it is mandatory in all FAI Cat 1 events. However, it is now very clear from feedback from International competition pilots that the workload in gleaning the "necessary" tactical data from the Flarm device is diminishing or eliminating the apparent added safety that the underlying Flarm provides.
What are pilots doing:-
1 Spending way too much time scanning moving maps for tactical contact detail instead of look out
2 Spending way too much time "tagging" competitors instead of look out to improve tactical content
3 Turning their Flarm units on and off at will to avoid tactical benefit accruing to others
4 Blanking antennas to reduce or eliminate range to avoid tactical benefit accruing to others
5 Installing amplifiers to increase range even further
6 Utilising two port Flarm units with one send/receive and one receive only antenna to maximise the range received but eliminate or restrict transmit range.
7 Changing backwards and forwards from "stealth" to full ON mode to minimize tactical benefit accruing to others but maximising own benefit as required.
Whats the effect
1 Safety is significantly diminished due to significant head in cockpit time inputting and viewing the Flarm for maximum tactical benefit.
2 Following or "leaching" is much easier so the eternal problem of gaggling is further encouraged at the possible cost of safety.
3 It is much easier for pilots of lower skill level to fly at the same XC speed as the best pilots.
What's the solution
When Flarm protocol was invented, it was thought that tactical advantage as described above may not be desirable in competition. So Flarm was designed with a "Stealth" protocol which degrades the information available to the pilot setting the mode and also to the pilot receiving that signal. So pilots can opt in or out of the tactical benefit and additionally the setting adopted is recorded on the IGC flight recorder. It was thought that this setting choice would be chosen at will by the pilot or prescribed by the competition ruling authority. Currently, IGC rules allow free choice of settings of Flarm unit.
One solution might be to mandate current Stealth mode for all events. This would certainly have a very significant effect and indeed was trialled by the BGA two years ago to fix all of the issues detailed above. However, it quickly became apparent that the current stealth mode, whilst eliminating the tactical benefit of Flarm, also reduces situational awareness in that targets that are not yet regarded as a threat do not appear on displays even if they are close by. The Flarm unit manufacturers themselves specifically do not recommend Stealth mode for this very reason although they comment in their literature that it is certainly better than pilots switching off their Flarm units. The BGA stealth trial was abandoned due to the forced situational awareness loss factor even though it was otherwise seen to be highly successful in restricting tactical benefit.
What is needed is a revised "IGC Stealth" protocol that has all the benefits and more but none off the pitfalls of the current stealth mode. Such a protocol would then be suitable for mandating by IGC and as required by all aero-clubs for National events.
In order to understand what is required, it is necessary to first understand what data is restricted to pilots when the current stealth mode is set - see table below.
Current stealth mode

Current stealth mode reduces situational awareness because all three factors in the amber column need to be true before 2d position, ID and Relative altitude with noise is available. This is why gliders very close to one another may not appear on displays but they can still very quickly become a threat - eg - a glider in the blind spot behind will not appear on the display of the pilot in front when both gliders are on similar track. Eg. Other gliders circling in same thermal will not always appear on display. Note that non of the basic audible and LED Flarm warnings are impaired if these are fitted.

Possible revised IGC stealth mode
A revised "IGC stealth mode" if implemented might look something like the table below:-

Here the ID is never available so it will never be possible to identify specific gliders so there will no longer be the requirement to attempt to "tag" other competitors thus reducing head down time and hence increasing safety. Also gliders remain unidentified from other competitors electronically at least thus satisfying the sporting argument too. With ID not being transmitted to others, pilots will be happier with the concept of the organisation possibly insisting on them being "tagged" for use by the competition organisation for purposes of glider competition tracking.
The 2d position and accurate relative altitude is available to all aircraft within 2km and 300m relative altitude. This allows all aircraft in the 600m x 2km disc to be visible at all times on graphic displays with accurate data for height so they may be monitored accurately. As the "ahead less than 45 degrees to track" requirement has been removed, situational awareness will be complete within the cylinder.
As no position or climb data is available outside the amber cylinder then the tactical benefit of seeing climb rates will be reduced but not eliminated. Also it will still be possible to follow other gliders provided any follower stays within 2km but it will be easier for trail-blazer to "escape" due to the relatively short distance and the lack of ID.
GLIDERS IN THE AMBER CYLINDER RETAIN FULL SITUATIONAL AWARENESS AT ALL TIMES
Conclusion and way forward
It is envisaged that the revised stealth parameters here should be checked for validity to achieve the desired result and then a dialogue be set up with Flarm to further check and implement.
Once available, the revised stealth mode should be made mandatory in all events

We had a few gliders in the first two days have problems getting into stealth mode due to (I think) display units which were reconfiguring their stealth. Another thing that can happen is someone leaves an old config file on the USB and downloads a flight and inadvertently reconfigs their unit. Once these pitfalls are understood their is really no issues with configuration.

On Monday, December 7, 2015 at 9:57:16 AM UTC-5, wrote:
On Monday, December 7, 2015 at 9:50:51 AM UTC-5, Sean Fidler wrote:
Excellent point. This smells rather rushed and "uncooked." If it was a development project from my team I would be concerned. One US contest late in the 2015 season and now the RC is already seriously considering a major change even before Flarm is mandatory accross all US contests or close to fully adopted. I think a year of careful testing (at least) is smart. The risk of a stealth mode "collision" still far outweighs the risk of a pilot getting a free thermal.

Perhaps FLARM et all (BGA, IGC, etc) should make a detailed statement to the public about the testing and development program underway for stealth mode and exact expextations/ requirements for safety and performance of collision alerts that are being worked towards.

This feels a lot like a synthetic vision avionics supplier doing an install and saying "go flying" in heavy IFR. It will be fine...

As requested- a year old, provided by Russell Cheatham. More development on the topic before long.
Text of the paper follows
UH

Flarm and the case for modified "Stealth" protocol
What's the problem
Range of Flarm now gives competitors the opportunity of identifying, locating and assessing the climb rate of competitors over 20km away. This has evolved with the production of better Flarm electronics (Powerflarm) and a better understanding of influence and importance of antenna location and design. Whilst the improved performance is most welcome as it now ensures that all installations are seeing and being seen at the important 2km range with much reduced blind spots(2km required for effective collision avoidance head to head), it has dramatically increased the tactical use by competition pilots.
Tactical benefits on task include being able to assess climb rate of others and identify where important pilots are in order to make improved strategic decisions. Even if the targets in view are not "tagged" they give important information for gliders behind to optimise routing and to ensure that if required a follower may ensure they fly the same route. Tactical benefit prior to start is even greater as it allows a full view of the start line area so it is clear where all the start gaggles are located, where key competitors are, whether they have started and sometimes what rate of climb is achieved in the first thermal on task.
It is arguable whether this sort of tactical assistance diminishes the art of racing gliders. I believe it does but this is not the main thrust of this paper. Flarm in isolation is a great safety device that has rightly been encouraged to the position we find ourselves today where it is mandatory in all FAI Cat 1 events. However, it is now very clear from feedback from International competition pilots that the workload in gleaning the "necessary" tactical data from the Flarm device is diminishing or eliminating the apparent added safety that the underlying Flarm provides.
What are pilots doing:-
1 Spending way too much time scanning moving maps for tactical contact detail instead of look out
2 Spending way too much time "tagging" competitors instead of look out to improve tactical content
3 Turning their Flarm units on and off at will to avoid tactical benefit accruing to others
4 Blanking antennas to reduce or eliminate range to avoid tactical benefit accruing to others
5 Installing amplifiers to increase range even further
6 Utilising two port Flarm units with one send/receive and one receive only antenna to maximise the range received but eliminate or restrict transmit range.
7 Changing backwards and forwards from "stealth" to full ON mode to minimize tactical benefit accruing to others but maximising own benefit as required.
Whats the effect
1 Safety is significantly diminished due to significant head in cockpit time inputting and viewing the Flarm for maximum tactical benefit.
2 Following or "leaching" is much easier so the eternal problem of gaggling is further encouraged at the possible cost of safety.
3 It is much easier for pilots of lower skill level to fly at the same XC speed as the best pilots.
What's the solution
When Flarm protocol was invented, it was thought that tactical advantage as described above may not be desirable in competition. So Flarm was designed with a "Stealth" protocol which degrades the information available to the pilot setting the mode and also to the pilot receiving that signal. So pilots can opt in or out of the tactical benefit and additionally the setting adopted is recorded on the IGC flight recorder. It was thought that this setting choice would be chosen at will by the pilot or prescribed by the competition ruling authority. Currently, IGC rules allow free choice of settings of Flarm unit.
One solution might be to mandate current Stealth mode for all events. This would certainly have a very significant effect and indeed was trialled by the BGA two years ago to fix all of the issues detailed above. However, it quickly became apparent that the current stealth mode, whilst eliminating the tactical benefit of Flarm, also reduces situational awareness in that targets that are not yet regarded as a threat do not appear on displays even if they are close by. The Flarm unit manufacturers themselves specifically do not recommend Stealth mode for this very reason although they comment in their literature that it is certainly better than pilots switching off their Flarm units. The BGA stealth trial was abandoned due to the forced situational awareness loss factor even though it was otherwise seen to be highly successful in restricting tactical benefit.
What is needed is a revised "IGC Stealth" protocol that has all the benefits and more but none off the pitfalls of the current stealth mode. Such a protocol would then be suitable for mandating by IGC and as required by all aero-clubs for National events.
In order to understand what is required, it is necessary to first understand what data is restricted to pilots when the current stealth mode is set - see table below.
Current stealth mode

Current stealth mode reduces situational awareness because all three factors in the amber column need to be true before 2d position, ID and Relative altitude with noise is available. This is why gliders very close to one another may not appear on displays but they can still very quickly become a threat - eg - a glider in the blind spot behind will not appear on the display of the pilot in front when both gliders are on similar track. Eg. Other gliders circling in same thermal will not always appear on display. Note that non of the basic audible and LED Flarm warnings are impaired if these are fitted.

Possible revised IGC stealth mode
A revised "IGC stealth mode" if implemented might look something like the table below:-

Here the ID is never available so it will never be possible to identify specific gliders so there will no longer be the requirement to attempt to "tag" other competitors thus reducing head down time and hence increasing safety. Also gliders remain unidentified from other competitors electronically at least thus satisfying the sporting argument too. With ID not being transmitted to others, pilots will be happier with the concept of the organisation possibly insisting on them being "tagged" for use by the competition organisation for purposes of glider competition tracking.
The 2d position and accurate relative altitude is available to all aircraft within 2km and 300m relative altitude. This allows all aircraft in the 600m x 2km disc to be visible at all times on graphic displays with accurate data for height so they may be monitored accurately. As the "ahead less than 45 degrees to track" requirement has been removed, situational awareness will be complete within the cylinder.
As no position or climb data is available outside the amber cylinder then the tactical benefit of seeing climb rates will be reduced but not eliminated. Also it will still be possible to follow other gliders provided any follower stays within 2km but it will be easier for trail-blazer to "escape" due to the relatively short distance and the lack of ID.
GLIDERS IN THE AMBER CYLINDER RETAIN FULL SITUATIONAL AWARENESS AT ALL TIMES
Conclusion and way forward
It is envisaged that the revised stealth parameters here should be checked for validity to achieve the desired result and then a dialogue be set up with Flarm to further check and implement.
Once available, the revised stealth mode should be made mandatory in all events

Hey, it occurs to me that the FLARM people sometimes participate in
searching for downed pilots. This is done by scanning the IGC files of
other pilots to identify the last known position of the missing plane.
What affect does stealth have with that function? If it does limit that
do we want to go down that road?

Matt

Fine...and thanks for sharing, but the level of urgency in US contests is simply not as critical as this is being made out to be. Why are we in a big hurry here to ad more rules and more work to contest participants? We (USA, SSA) should be very late adopters of stealth mode, and when the tech is fully proven and stable, not early, bleeding edge adopters. We have many contest pilots who refuse to use Flarm at all, for example. This rapid change to stealth mode makes no sense. Personally I still feel that Flarm is highly vulnerable with many gliders not equipped. It's too easy to get a false sense of security and lower your defenses of relying on the visual scan when 85% have Flarm. It's the other 15% that will cause the next US contest collision IMO. I'm assuming safety is still the 99% key function of Flarm.

The US has far larger problems right now, and there is a reasonable safety concern here. We need to be very cautious, test, and move slowly on this. There is no real urgency to change IMO. And, if you guys are basing this on the opinion poll or even this thread, there is clearly no consensus yet.

If Flarm stealth mode was proven and tested, it would be a different story of course as on paper it makes good sense. But it's not.

Jerzy makes some good points too.

Sean

Can someone forward me Montys email address? TIA

Sean

On Sunday, December 6, 2015 at 10:00:08 PM UTC-7, Sean Fidler wrote:
I honestly really don't care what mode is used but overall, the supposed problem feels a little over dramatic. I don't think it will make a big difference. Perhaps I am wrong. The good news is I can keep flying happily with my SN10 as the Flarm leeching "picture" offered by the modern computers was one of the potential reasons to consider buying something more sophisticated. Now, that feature doesn't appear to matter as much, if at all. So, mainly for that reason, I fully support "Stealth mode!"

7T

Sean - Your various posts are confusing to me. You said in the post above you "fully support Stealth mode!" and then in later posts don't seem to think it should be rushed. Was the first statement a typo and you were trying to say the opposite?

Bruno - B4