PowerFlarm and ADS-B solution, can we find one?

On Saturday, January 9, 2016 at 12:14:07 PM UTC-5, Dan Marotta wrote:
Hi Kirk,



Yes, I've towed you during at least one contest at Moriarty and I've
admired your LS-6.



Please understand that I don't "poo-poo" Flarm in my comments, I
only respond to the comments of some, which I believe are
unreasonable or downright wrong.* I always welcome logical proofs
like the math-based analysis of the pull-up (in a previous thread).



And yes, I think Flarm is a great tool for situational awareness but
I don't think that knowing a blip's ID is a requirement for safety.*
And I'm neither for nor against "stealth" mode - I don't care either
way.* The idea of coordinating an escape plan with another aircraft
5 miles away by radio is simply ludicrous.* Remember when contests
were fully manned and there was no Flarm or GPS?* I'm not against
either, as a lot of the folks here think, but I think a lot of the
fun has gone and that's the main reason I don't fly contests any
more.



So why do I keep posting?* It's out of a genuine concern that false
perceptions, unchallenged, will eventually become policy, and I
don't want any more policies.


Thank you Dan for your posts. Your opinion is important, too. I especially agree with this last paragraph.

I'll give you one example that needs to be challenged stated just a little while back. One post says"the requisite 45 seconds" and goes into some simple calculations based on 45 seconds on the display. I would like to see some actual physics calculated, but aside from that there is no basis for the 45 seconds. This is the kind of overstatement I keep talking about. It is not a lie but people are trying so hard to make their case for the outcome they desire they sometimes overstate the facts.

Pull out your iPhone and run the timer for 45seconds and you'll see it is a lot of time. There are other alternatives that may help. When a new target appears on the screen there can be simple audio alert letting you know of the new bogie. I would suggest that in this case 25 seconds of warning is plenty if collision avoidance is what you are really after. Don't take my word for it though, use some real science to come up with a real number.

The TCAS operators guide that I am looking at allows 5 secs as the outside reaction time to initiate corrective action (pitch change in the case of TCAS) resolution advisory. This is similar to the FLARM warning when a collision path is detected. I don't have complete TCAS specs readily available but perhaps other time values from TCAS could be used since their research is probably more thorough.

It makes a big difference in the final numbers if you use 45 seconds or 25 seconds. Let's make sure these numbers are based on some evidence.

XC

On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

On Saturday, January 9, 2016 at 5:30:48 PM UTC-7, jfitch wrote:
On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

TCAS is a completely different kind of system designed to work in an IFR environment. It is not GPS based. It is on board radar / transponder based. It gives specific commands to the flight crew to avoid the possible collision. Simple pull up or push over commands. The crew is expected to just do what the machine says, then tell ATC they got an RA and that's why they deviated. Visually spotting the traffic is irrelevant. Reaction time is just how quickly the crew can execute the command. No decision about what to do, just safely interrupt current process and execute.

FLARM makes absolutely no attempt to recommend how to avoid a collision. It just points out traffic and highlights potentially conflicting traffic based on the assumption both aircraft will continue to do what they have been doing. Its up to the pilot(s) to decide what to do, preferably after visually spotting the threat.

On Saturday, January 9, 2016 at 7:30:48 PM UTC-5, jfitch wrote:
On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

More details about TCAS for comparison:

5 sec. is the maximum expected reaction time for a warning or RA. That is with the autopilot engaged and the pilot not actively engaged on the flight controls. The anticipated reaction time to reverse, increase or decrease vertical speed once the pilot is flying the machine is 2.5 sec.

"Initial vertical speed reaction to a RA is expected within 5 seconds; maneuvering G forces should be similar to those felt when responding to an ATC clearance to climb or defend "immediately" (+/- 0.25 G change in load factor)." That doesn't sound too panicked.

The TCAS display is selectable Above/Norm/Below. My company recommends normal in all phases of flight which gives +/- 2700 ft on the display. This is for aircraft capable of climbing or descending 6000 ft/min. "Above" can be selected in the climb which would give a view of aircraft 7000 ft above and 2700 ft below.

Now this is a different system, I understand, but my point is that it is not cross referenced continuously as a source of SA. Rather, it is an alert system that provides traffic advisories (TA) as aircraft are getting to be a factor ("Traffic") and resolution advisories (RA) ("Traffic, Climb/Descend)"when action is required by the pilot. The audio alerts and warnings have priority and have been determined to be more effective than the instrument panel display for collision avoidance.

Similarly, displaying all traffic on FLARM at these greater distances and relative altitudes is not required for SA or collision avoidance. In fact, spending too much time looking down at the display may be contrary to safety.. Again, this discussion goes beyond collision avoidance and gets into pilots wanting to track other gliders for tactical reasons.

XC

On Saturday, January 9, 2016 at 5:47:04 PM UTC-8, XC wrote:
On Saturday, January 9, 2016 at 7:30:48 PM UTC-5, jfitch wrote:
On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

More details about TCAS for comparison:

5 sec. is the maximum expected reaction time for a warning or RA. That is with the autopilot engaged and the pilot not actively engaged on the flight controls. The anticipated reaction time to reverse, increase or decrease vertical speed once the pilot is flying the machine is 2.5 sec.

"Initial vertical speed reaction to a RA is expected within 5 seconds; maneuvering G forces should be similar to those felt when responding to an ATC clearance to climb or defend "immediately" (+/- 0.25 G change in load factor)." That doesn't sound too panicked.

The TCAS display is selectable Above/Norm/Below. My company recommends normal in all phases of flight which gives +/- 2700 ft on the display. This is for aircraft capable of climbing or descending 6000 ft/min. "Above" can be selected in the climb which would give a view of aircraft 7000 ft above and 2700 ft below.

Now this is a different system, I understand, but my point is that it is not cross referenced continuously as a source of SA. Rather, it is an alert system that provides traffic advisories (TA) as aircraft are getting to be a factor ("Traffic") and resolution advisories (RA) ("Traffic, Climb/Descend)"when action is required by the pilot. The audio alerts and warnings have priority and have been determined to be more effective than the instrument panel display for collision avoidance.

Similarly, displaying all traffic on FLARM at these greater distances and relative altitudes is not required for SA or collision avoidance. In fact, spending too much time looking down at the display may be contrary to safety. Again, this discussion goes beyond collision avoidance and gets into pilots wanting to track other gliders for tactical reasons.

XC

In searching for the best anti collision system, few people hold out TCAS as the ideal. I have heard much more criticism of it than praise, the latter usually confined to "it's better than nothing". This is why the regulators and industry worldwide are moving as fast as they possibly can towards ADS-B, a system much more like Flarm. Before we decide that the metrics of TCAS are ideal or even adequate, we should ask why that system is being discarded in favor of one that shows all aircraft within 15 miles, all the time: position, altitude, and tail number. Going by that metric, the FAA has already decided that 15 miles range is the right answer. Even at 1000 mph closing speed, 15 miles gives over 50 seconds warning. I propose 50 seconds is the best supported number.

On Saturday, January 9, 2016 at 11:07:04 PM UTC-8, jfitch wrote:
On Saturday, January 9, 2016 at 5:47:04 PM UTC-8, XC wrote:
On Saturday, January 9, 2016 at 7:30:48 PM UTC-5, jfitch wrote:
On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

More details about TCAS for comparison:

5 sec. is the maximum expected reaction time for a warning or RA. That is with the autopilot engaged and the pilot not actively engaged on the flight controls. The anticipated reaction time to reverse, increase or decrease vertical speed once the pilot is flying the machine is 2.5 sec.

"Initial vertical speed reaction to a RA is expected within 5 seconds; maneuvering G forces should be similar to those felt when responding to an ATC clearance to climb or defend "immediately" (+/- 0.25 G change in load factor)." That doesn't sound too panicked.

The TCAS display is selectable Above/Norm/Below. My company recommends normal in all phases of flight which gives +/- 2700 ft on the display. This is for aircraft capable of climbing or descending 6000 ft/min. "Above" can be selected in the climb which would give a view of aircraft 7000 ft above and 2700 ft below.

Now this is a different system, I understand, but my point is that it is not cross referenced continuously as a source of SA. Rather, it is an alert system that provides traffic advisories (TA) as aircraft are getting to be a factor ("Traffic") and resolution advisories (RA) ("Traffic, Climb/Descend)"when action is required by the pilot. The audio alerts and warnings have priority and have been determined to be more effective than the instrument panel display for collision avoidance.

Similarly, displaying all traffic on FLARM at these greater distances and relative altitudes is not required for SA or collision avoidance. In fact, spending too much time looking down at the display may be contrary to safety. Again, this discussion goes beyond collision avoidance and gets into pilots wanting to track other gliders for tactical reasons.

XC

In searching for the best anti collision system, few people hold out TCAS as the ideal. I have heard much more criticism of it than praise, the latter usually confined to "it's better than nothing". This is why the regulators and industry worldwide are moving as fast as they possibly can towards ADS-B, a system much more like Flarm. Before we decide that the metrics of TCAS are ideal or even adequate, we should ask why that system is being discarded in favor of one that shows all aircraft within 15 miles, all the time: position, altitude, and tail number. Going by that metric, the FAA has already decided that 15 miles range is the right answer. Even at 1000 mph closing speed, 15 miles gives over 50 seconds warning. I propose 50 seconds is the best supported number.

Oh what a pile of utter nonsense. TCAS II *is* the gold standard in collision avoidance. ADS-B does not replace TCAS II in *any* way. Not a single FAA regulation currently or proposed allows for replacement of TCAS II mandatory carriage with any ADS-B product.

TCAS II is not being discarded/abandoned for anything, including ADS-B anything. There is no technology that uses ADS-B for active collision avoidance similar to TCAS available as any RTCA standard and so nothing that can be build and no research projects that could be turned into such a standards any time soon. So at best anything based on ADS-B would likely be decades away. I have now idea where you are getting this 15 miles from. The ADS-B ground services hockey-puck diameter? That really has no direct relevance to TCAS. It is a stopgap layered on a complex dual-link mess.

TCAS II version 7.1 (the current standard) makes use of ADS-B In data to reduce the activeTCAS II transponder interrogation rates and provide better long range tracking of targets (esp. without excessive RF congestion). These systems do not use ADS-B data to issue an RA, that is all determined by active TCAS II to transponder interrogation. One of the specific advantages of Change 7.1 ADS-B integration is improved long range (much longer than 15nm you mention) traffic display... which in USA Class A airspace they will be able to rely on every aircraft being quipped with after 2020.

So not a single thing you stated is correct.

On Saturday, January 9, 2016 at 11:54:33 PM UTC-8, Darryl Ramm wrote:
On Saturday, January 9, 2016 at 11:07:04 PM UTC-8, jfitch wrote:
On Saturday, January 9, 2016 at 5:47:04 PM UTC-8, XC wrote:
On Saturday, January 9, 2016 at 7:30:48 PM UTC-5, jfitch wrote:
On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

More details about TCAS for comparison:

5 sec. is the maximum expected reaction time for a warning or RA. That is with the autopilot engaged and the pilot not actively engaged on the flight controls. The anticipated reaction time to reverse, increase or decrease vertical speed once the pilot is flying the machine is 2.5 sec.

"Initial vertical speed reaction to a RA is expected within 5 seconds; maneuvering G forces should be similar to those felt when responding to an ATC clearance to climb or defend "immediately" (+/- 0.25 G change in load factor)." That doesn't sound too panicked.

The TCAS display is selectable Above/Norm/Below. My company recommends normal in all phases of flight which gives +/- 2700 ft on the display. This is for aircraft capable of climbing or descending 6000 ft/min. "Above" can be selected in the climb which would give a view of aircraft 7000 ft above and 2700 ft below.

Now this is a different system, I understand, but my point is that it is not cross referenced continuously as a source of SA. Rather, it is an alert system that provides traffic advisories (TA) as aircraft are getting to be a factor ("Traffic") and resolution advisories (RA) ("Traffic, Climb/Descend)"when action is required by the pilot. The audio alerts and warnings have priority and have been determined to be more effective than the instrument panel display for collision avoidance.

Similarly, displaying all traffic on FLARM at these greater distances and relative altitudes is not required for SA or collision avoidance. In fact, spending too much time looking down at the display may be contrary to safety. Again, this discussion goes beyond collision avoidance and gets into pilots wanting to track other gliders for tactical reasons.

XC

In searching for the best anti collision system, few people hold out TCAS as the ideal. I have heard much more criticism of it than praise, the latter usually confined to "it's better than nothing". This is why the regulators and industry worldwide are moving as fast as they possibly can towards ADS-B, a system much more like Flarm. Before we decide that the metrics of TCAS are ideal or even adequate, we should ask why that system is being discarded in favor of one that shows all aircraft within 15 miles, all the time: position, altitude, and tail number. Going by that metric, the FAA has already decided that 15 miles range is the right answer. Even at 1000 mph closing speed, 15 miles gives over 50 seconds warning. I propose 50 seconds is the best supported number.

Oh what a pile of utter nonsense. TCAS II *is* the gold standard in collision avoidance. ADS-B does not replace TCAS II in *any* way. Not a single FAA regulation currently or proposed allows for replacement of TCAS II mandatory carriage with any ADS-B product.

TCAS II is not being discarded/abandoned for anything, including ADS-B anything. There is no technology that uses ADS-B for active collision avoidance similar to TCAS available as any RTCA standard and so nothing that can be build and no research projects that could be turned into such a standards any time soon. So at best anything based on ADS-B would likely be decades away. I have now idea where you are getting this 15 miles from. The ADS-B ground services hockey-puck diameter? That really has no direct relevance to TCAS. It is a stopgap layered on a complex dual-link mess.

TCAS II version 7.1 (the current standard) makes use of ADS-B In data to reduce the activeTCAS II transponder interrogation rates and provide better long range tracking of targets (esp. without excessive RF congestion). These systems do not use ADS-B data to issue an RA, that is all determined by active TCAS II to transponder interrogation. One of the specific advantages of Change 7.1 ADS-B integration is improved long range (much longer than 15nm you mention) traffic display... which in USA Class A airspace they will be able to rely on every aircraft being quipped with after 2020.

So not a single thing you stated is correct.

I should have said, "ADS-B is being incorporated into TCAS to make up for its shortcomings". According to reports, TCAS IV was abandon in favor of ADS-B enhancements. A couple of the main enhancements in question being accurate position, vector and ID information, precisely the things stealth advocates want to suppress. Whether we are talking about TCAS or ADS-B or ADS-B enhanced TCAS, there is not even a suggestion that the FAA thinks 5 seconds is adequate for anything but a last ditch panic maneuver.

There is a parallel in shipping collision avoidance, which depended on automated radar tracking aids for many years. This has been replaced in less than a decade by a GPS based digital network operated on VHF. No one I know wants to go back as it is far superior to radar tracking. In all of these systems, situational awareness is considered the first line of defense against collision, and automated warnings intended as a stop gap to cover cases where situational awareness was lost.

On Sunday, January 10, 2016 at 1:00:09 PM UTC-5, jfitch wrote:
On Saturday, January 9, 2016 at 11:54:33 PM UTC-8, Darryl Ramm wrote:
On Saturday, January 9, 2016 at 11:07:04 PM UTC-8, jfitch wrote:
On Saturday, January 9, 2016 at 5:47:04 PM UTC-8, XC wrote:
On Saturday, January 9, 2016 at 7:30:48 PM UTC-5, jfitch wrote:
On Saturday, January 9, 2016 at 12:08:39 PM UTC-8, XC wrote:
SNIPLet's make sure these numbers are based on some evidence.

Based on evidence presented so far, we don't even have a need for a stealth, so that is an odd statement.

The 5 second TCAS has got to be a minimum, panic mode number. Also do not just consider the case of one glider meeting one glider. Consider 5 gliders meeting 5 gliders. No longer can you just turn right or pull up, doing so may well cause an accident rather than prevent one.

More details about TCAS for comparison:

5 sec. is the maximum expected reaction time for a warning or RA. That is with the autopilot engaged and the pilot not actively engaged on the flight controls. The anticipated reaction time to reverse, increase or decrease vertical speed once the pilot is flying the machine is 2.5 sec.

"Initial vertical speed reaction to a RA is expected within 5 seconds; maneuvering G forces should be similar to those felt when responding to an ATC clearance to climb or defend "immediately" (+/- 0.25 G change in load factor)." That doesn't sound too panicked.

The TCAS display is selectable Above/Norm/Below. My company recommends normal in all phases of flight which gives +/- 2700 ft on the display. This is for aircraft capable of climbing or descending 6000 ft/min. "Above" can be selected in the climb which would give a view of aircraft 7000 ft above and 2700 ft below.

Now this is a different system, I understand, but my point is that it is not cross referenced continuously as a source of SA. Rather, it is an alert system that provides traffic advisories (TA) as aircraft are getting to be a factor ("Traffic") and resolution advisories (RA) ("Traffic, Climb/Descend)"when action is required by the pilot. The audio alerts and warnings have priority and have been determined to be more effective than the instrument panel display for collision avoidance.

Similarly, displaying all traffic on FLARM at these greater distances and relative altitudes is not required for SA or collision avoidance. In fact, spending too much time looking down at the display may be contrary to safety. Again, this discussion goes beyond collision avoidance and gets into pilots wanting to track other gliders for tactical reasons.

XC

In searching for the best anti collision system, few people hold out TCAS as the ideal. I have heard much more criticism of it than praise, the latter usually confined to "it's better than nothing". This is why the regulators and industry worldwide are moving as fast as they possibly can towards ADS-B, a system much more like Flarm. Before we decide that the metrics of TCAS are ideal or even adequate, we should ask why that system is being discarded in favor of one that shows all aircraft within 15 miles, all the time: position, altitude, and tail number. Going by that metric, the FAA has already decided that 15 miles range is the right answer. Even at 1000 mph closing speed, 15 miles gives over 50 seconds warning. I propose 50 seconds is the best supported number.

Oh what a pile of utter nonsense. TCAS II *is* the gold standard in collision avoidance. ADS-B does not replace TCAS II in *any* way. Not a single FAA regulation currently or proposed allows for replacement of TCAS II mandatory carriage with any ADS-B product.

TCAS II is not being discarded/abandoned for anything, including ADS-B anything. There is no technology that uses ADS-B for active collision avoidance similar to TCAS available as any RTCA standard and so nothing that can be build and no research projects that could be turned into such a standards any time soon. So at best anything based on ADS-B would likely be decades away. I have now idea where you are getting this 15 miles from. The ADS-B ground services hockey-puck diameter? That really has no direct relevance to TCAS. It is a stopgap layered on a complex dual-link mess.

TCAS II version 7.1 (the current standard) makes use of ADS-B In data to reduce the activeTCAS II transponder interrogation rates and provide better long range tracking of targets (esp. without excessive RF congestion). These systems do not use ADS-B data to issue an RA, that is all determined by active TCAS II to transponder interrogation. One of the specific advantages of Change 7.1 ADS-B integration is improved long range (much longer than 15nm you mention) traffic display... which in USA Class A airspace they will be able to rely on every aircraft being quipped with after 2020.

So not a single thing you stated is correct.

I should have said, "ADS-B is being incorporated into TCAS to make up for its shortcomings". According to reports, TCAS IV was abandon in favor of ADS-B enhancements. A couple of the main enhancements in question being accurate position, vector and ID information, precisely the things stealth advocates want to suppress. Whether we are talking about TCAS or ADS-B or ADS-B enhanced TCAS, there is not even a suggestion that the FAA thinks 5 seconds is adequate for anything but a last ditch panic maneuver.

There is a parallel in shipping collision avoidance, which depended on automated radar tracking aids for many years. This has been replaced in less than a decade by a GPS based digital network operated on VHF. No one I know wants to go back as it is far superior to radar tracking. In all of these systems, situational awareness is considered the first line of defense against collision, and automated warnings intended as a stop gap to cover cases where situational awareness was lost.

While I "mostly read" these discussions, I would like to say that the FAA is looking at mostly commercial traffic (when writing rules for distance & timing of TCAS/etc.) where you have 250KTS for each aircraft (500KTS closure, below 10K') and more speed higher.
Rarely do you have sailplanes doing 250KTS closure, let alone airspeed (maybe opposing ridge runs, western US big cloud streets), thus what the FAA is looking for in collision avoidance is just, "a wee bit different" than what sailplanes are looking for.

Granted, more time is better, more heads up time is better, basically we seem to have a "****ing contest" going on but since I'm not a current US contest pilot, I sorta just sit back and watch what is going on (so I have an idea on what to expect down the road).

If I could vote on a rule for "what to do with Flarm in a US contest", I would likely vote to:
-Reduce our range to 5KM (likely proposed US RC idea)
-Squash contest ID & "rate of climb" outside of 5KM
-Keep full info within 5KM to aid in collision avoidance per whatever Flarm can provide (yes, there will be cases that even the best algorithm gets befuddled....)

I'm speaking for myself, I'm NOT speaking for anyone else, nor do I have outside input to the US RC.

PS, I also understand that potential upcoming US FAA rules may make some of this moot, even current US contest pilots (with certified installed equipment) may make this whole discussion rather moot.
I also ask myself, "Why do some push their Flarm agenda so hard, do they want to change the sport today rather than wait until the FAA does it for them?!?!".

I don't know although I have my own ideas I won't really share.

XC,

Again, you assume the flawless function of the Flarm system. 25 seconds, if the Flarm "network" is not perfectly functional due to say structural interference, may be reduced to 5 seconds. Or zero. Arbitrary discussions about were "safety ends" and "philosophical Flarm fairness?" (whatever the hell this should be) begins has proven quite frightening to observe.

The longer the time period the Flarm has to make a potential warning (beep as "bogey" appears), the better. This is a fact (from a safety viewpoint). Artificial reductions in Flarms engineered performance potential will by definition also increase the odds of a dangerous situation occurring. While being far better than nothing, the Flarm network is still prone to regular coverage challenges and clearly does not have, perfect, 100%, 360 degree coverage at all times. Far, FAR from it.

We need to kill this whole idea for at least one year. It's out of control.. It is irresponsible (at best) to screw around with Flarms potential range at this point. The unintended consequences are potentially huge. The philosophical competitive "fairness" argument is simply no peer to safety. It's not even on the same planet as safety. Stop treating this discussion like this as a debate between equals. Start respecting the fact that Flarm, while valuable for safety, is far, far from perfect or infallible. So when you say a supposed time value that you find acceptable for your little crusade, imagine that the gliders 25 seconds away from a potential collision are not seeing each others antenna at 25 seconds for whatever reason. Or maybe you get a proximity "beep" and then lose coverage for 15 seconds.

Bottom line, some here care far more about philosophical fairness arguments than the significant safety value Flarm provides via its ability to create situational awareness for us. This crusade become an literal obsession for some.

I won't debate or compromise Flarm at this point until some sort of impartial, objective study (and extensive testing) has been completed. This was the requirement of my initial support for a limitation. Since then, the almost reckless abandon that many supporters (almost certainly coordinated in a pseudo RAS Flarm "mode" campaign) have demonstrated here is a real problem. The USRC opinion poll does not support this desperate position.

Perhaps the FAA should be involved. Has anyone discussed this topic with the FAA? I wonder what their take would be.

Sean

On Sunday, January 10, 2016 at 12:57:03 AM UTC-5, smfidler wrote:
XC,

Again, you assume the flawless function of the Flarm system. 25 seconds, if the Flarm "network" is not perfectly functional due to say structural interference, may be reduced to 5 seconds. Or zero. Arbitrary discussions about were "safety ends" and "philosophical Flarm fairness?" (whatever the hell this should be) begins has proven quite frightening to observe.

The longer the time period the Flarm has to make a potential warning (beep as "bogey" appears), the better. This is a fact (from a safety viewpoint). Artificial reductions in Flarms engineered performance potential will by definition also increase the odds of a dangerous situation occurring. While being far better than nothing, the Flarm network is still prone to regular coverage challenges and clearly does not have, perfect, 100%, 360 degree coverage at all times. Far, FAR from it.

We need to kill this whole idea for at least one year. It's out of control. It is irresponsible (at best) to screw around with Flarms potential range at this point. The unintended consequences are potentially huge. The philosophical competitive "fairness" argument is simply no peer to safety. It's not even on the same planet as safety. Stop treating this discussion like this as a debate between equals. Start respecting the fact that Flarm, while valuable for safety, is far, far from perfect or infallible. So when you say a supposed time value that you find acceptable for your little crusade, imagine that the gliders 25 seconds away from a potential collision are not seeing each others antenna at 25 seconds for whatever reason. Or maybe you get a proximity "beep" and then lose coverage for 15 seconds.

Bottom line, some here care far more about philosophical fairness arguments than the significant safety value Flarm provides via its ability to create situational awareness for us. This crusade become an literal obsession for some.

I won't debate or compromise Flarm at this point until some sort of impartial, objective study (and extensive testing) has been completed. This was the requirement of my initial support for a limitation. Since then, the almost reckless abandon that many supporters (almost certainly coordinated in a pseudo RAS Flarm "mode" campaign) have demonstrated here is a real problem. The USRC opinion poll does not support this desperate position.

Perhaps the FAA should be involved. Has anyone discussed this topic with the FAA? I wonder what their take would be.


I was just pointing out some of the time values involved in operating with TCAS. I suspect that research was more extensive and the technology is more proven. Many TCAS resolution advisories occur before they are displayed as targets on the screen. The pilot's eyes are directed to the display (on the VSI in our case) to make a correction because it is a system used during IFR.

With FLARM the eyes are directed outside as they should be. The best way to do this is through the audio warning system. More could be done with this to improve safety. For example, there could be a warning "Multiple traffic, One o'clock high." This is another real suggestion that would enhance the FLARM system. The TCAS time values are real numbers to add perspective to the discussion.

XC