PowerFLARM leeching comments

On Sunday, October 21, 2012 6:41:11 PM UTC-5, Evan Ludeman wrote:
On Oct 21, 7:35*pm, wrote:

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)



See pg 19 of the PowerFlarm Dataport Specification for details about

how stealth mode works.



It's he http://tinyurl.com/8ne9cjx



Stealth mode does not change the anti-collision functionality of

PowerFlarm at all. You'll get the get the same 25 seconds warning,

which is plenty.



Evan Ludeman / T8

"Plenty" is interesting. Let's all remember, flarm is not a "collision avoidance" device. It is a "collision warning" device. You still have to find the other glider, avoid it, and not run in to anyone else while you're doing that. Don't just bank away from the collision threat, make sure there isn't a new collision threat.

If glider A is a collision threat, glider B is off to your side and not a collision threat, will flarm show glider B in stealth mode? No, I gather. If you suddenly bank towards glider B to avoid glider A...

And it doesn't always give 25 seconds warning, especially if carbon fuselages are blocking signals. Gliders have collided when both had operating flarm systems. Norway and Uvalde.

A stealth mode is far from obviously a good idea, if it only shows imminent collision threats. The operation and reliability of such a mode have to be really bulletproof. Which, given power flarm's recent history with range issues, software updates, antenna updates etc., would seem to be something one would want a lot of real world experience with. But how do we get real world experience and find out its actual limitations?

It's interesting how many reports we're getting of pilots who saw collision threats with flarm. But we obviously don't know about the failures until they hit each other. And how do we learn about the failures under stealth mode. Can of worms here.


John Cochrane

On Sunday, October 21, 2012 6:52:17 PM UTC-7, wrote:
On Sunday, October 21, 2012 6:41:11 PM UTC-5, Evan Ludeman wrote:

On Oct 21, 7:35*pm, wrote:



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)







See pg 19 of the PowerFlarm Dataport Specification for details about



how stealth mode works.







It's he http://tinyurl.com/8ne9cjx







Stealth mode does not change the anti-collision functionality of



PowerFlarm at all. You'll get the get the same 25 seconds warning,



which is plenty.







Evan Ludeman / T8



"Plenty" is interesting. Let's all remember, flarm is not a "collision avoidance" device. It is a "collision warning" device. You still have to find the other glider, avoid it, and not run in to anyone else while you're doing that. Don't just bank away from the collision threat, make sure there isn't a new collision threat.



If glider A is a collision threat, glider B is off to your side and not a collision threat, will flarm show glider B in stealth mode? No, I gather. If you suddenly bank towards glider B to avoid glider A...



And it doesn't always give 25 seconds warning, especially if carbon fuselages are blocking signals. Gliders have collided when both had operating flarm systems. Norway and Uvalde.



A stealth mode is far from obviously a good idea, if it only shows imminent collision threats. The operation and reliability of such a mode have to be really bulletproof. Which, given power flarm's recent history with range issues, software updates, antenna updates etc., would seem to be something one would want a lot of real world experience with. But how do we get real world experience and find out its actual limitations?



It's interesting how many reports we're getting of pilots who saw collision threats with flarm. But we obviously don't know about the failures until they hit each other. And how do we learn about the failures under stealth mode. Can of worms here.





John Cochrane

I agree with John. I find the situational awareness as important as the collision alert. Also, not sure where the 25 sec came from, but when I was on a head on with another glider at 17K both of us flying above 100 knots TAS, the warning we got was more like 10 seconds, just enough to react and bank away. We never saw each other until we banked away, but luckily we saw each other on flarm radar 5 miles away giving us plenty time to be alerted and be prepared to change course. I sure hope no one will fly in stealth mode.

Ramy

On Sunday, October 21, 2012 9:52:17 PM UTC-4, wrote:
If glider A is a collision threat, glider B is off to your side
and not a collision threat, will flarm show glider B in stealth mode?
No, I gather.
If you suddenly bank towards glider B to avoid glider A...

Correct.


And it doesn't always give 25 seconds warning, especially if
carbon fuselages are blocking signals.

And especially if pilots have not followed sensible practice
installing the antennas, or used antennas with no radiation
downwards. Speak to your fellow pilots when you see this,
it could be your life...


A stealth mode is far from obviously a good idea, if it only
shows imminent collision threats. The operation and reliability
of such a mode have to be really bulletproof.
gratuitous obnoxious comment snipped
... would seem to be something one would want a lot of real world
experience with. But how do we get real world experience and find
out its actual limitations?

One could possibly pay attention to foreign experience, where many
thousands of FLARM have been deployed for years, instead of
provincially continually reinventing the wheel...

Just a far-out idea, wishful thinking no doubt...

On Sunday, October 21, 2012 9:52:17 PM UTC-4, wrote:
On Sunday, October 21, 2012 6:41:11 PM UTC-5, Evan Ludeman wrote:

On Oct 21, 7:35*pm, wrote:



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)







See pg 19 of the PowerFlarm Dataport Specification for details about



how stealth mode works.







It's he http://tinyurl.com/8ne9cjx







Stealth mode does not change the anti-collision functionality of



PowerFlarm at all. You'll get the get the same 25 seconds warning,



which is plenty.







Evan Ludeman / T8



"Plenty" is interesting. Let's all remember, flarm is not a "collision avoidance" device. It is a "collision warning" device. You still have to find the other glider, avoid it, and not run in to anyone else while you're doing that. Don't just bank away from the collision threat, make sure there isn't a new collision threat.



If glider A is a collision threat, glider B is off to your side and not a collision threat, will flarm show glider B in stealth mode? No, I gather. If you suddenly bank towards glider B to avoid glider A...



And it doesn't always give 25 seconds warning, especially if carbon fuselages are blocking signals. Gliders have collided when both had operating flarm systems. Norway and Uvalde.



A stealth mode is far from obviously a good idea, if it only shows imminent collision threats. The operation and reliability of such a mode have to be really bulletproof. Which, given power flarm's recent history with range issues, software updates, antenna updates etc., would seem to be something one would want a lot of real world experience with. But how do we get real world experience and find out its actual limitations?



It's interesting how many reports we're getting of pilots who saw collision threats with flarm. But we obviously don't know about the failures until they hit each other. And how do we learn about the failures under stealth mode. Can of worms here.





John Cochrane

If there's a comm problem between flarm transceivers, then the operating mode simply doesn't matter. One advantage of the open mode is that it provides a means to test the system performance without aerial jousting. And yeah, I see a lot of carbon gliders (V2's mainly) with really spotty contact.

Short warning time when comm is established probably reflects maneuvering, i.e. a course conflict that arose "unexpectedly". For high speed head on traffic, "maneuvering" doesn't necessarily mean much. A small heading/glide slope change is all it would take.

T8

At 23:35 21 October 2012, wrote:
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,


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)

From the FLARM manual

"Stealth mode inherently reduces some of the benefits of situation
awareness for yourself and surrounding aircraft. We do not recommend the
use of Stealth mode, but it is better than turning FLARM® off for tactical
reasons."
There is no way that the above can be interpreted in any way other than the
safety benefits are reduced. Do you really want to be seen being
responsible for telling pilots to reduce safety?

http://www.flarm.com/support/Flarm_Competitions.pdf

On Sunday, October 28, 2012 4:45:03 AM UTC-4, Don Johnstone wrote:
At 23:35 21 October 2012, wrote:

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,





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)



From the FLARM manual



"Stealth mode inherently reduces some of the benefits of situation

awareness for yourself and surrounding aircraft. We do not recommend the

use of Stealth mode, but it is better than turning FLARM® off for tactical

reasons."

There is no way that the above can be interpreted in any way other than the

safety benefits are reduced. Do you really want to be seen being

responsible for telling pilots to reduce safety?



http://www.flarm.com/support/Flarm_Competitions.pdf

It's a matter of how much warning and of what type is useful and actionable..

You have not actually flown with PowerFlarm "radar", have you?

The amount of head down time required to develop any actionable information from present flarm radar screens is scary large. In fact I would argue that given only flarm/butterfly panel mount displays currently available we'll be safer with everyone in stealth mode simply because there will be less to look at on the panel and eyes may stay outside a little more. 3rd parties will solve the display problem even if Flarm doesn't, but the fact remains that radar in open mode shows you mostly targets that are not and will never become collision threats.

Read (I tire of saying this) the dataport spec. Page 19. It describes in detail what stealth mode actually does. Among other things, you'll find that it still displays all radar targets that might become a collision threat.. I can make the argument that this enhances safety because it does not so clutter the display with non-threats.

Evan Ludeman / T8

At 11:40 28 October 2012, Evan Ludeman wrote:
On Sunday, October 28, 2012 4:45:03 AM UTC-4, Don Johnstone wrote:
At 23:35 21 October 2012, wrote:
=20
On Saturday, October 20, 2012 5:52:55 PM UTC-4, Dave Nadler wrote:
=20
On Saturday, October 20, 2012 5:30:05 PM UTC-4, Don Johnstone wrote:
=20
=20
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I was very uncomfortable with the concept of instructing pilots to
lesse=
n
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the efficiency of an anti-colision assistance device.
=20
=20
=20
Stealth mode in no way lessens the efficacy of FLARM anti-collision.
It
=20
gives you warnings when there is a collision hazard regardless.
=20
Hope that is clear,
=20
=20
=20

=20
Dave,
=20

=20
it is clear, and while your statement is probably technically
accurate,
=20
it
=20
isn't entirely correct. Any mode that reduces the pilot's situational
=20
awareness also degrades safety to some extent. Stealth mode by
definition
=20
does exactly that. The OC fatality scenario is a case where stealth
mode
=20
might
=20
not provide enough warning to assess the situation and take appropriate
=20
=20
=20
action, whereas the 'full' mode probably would. Just my $0.02
=20

=20
Frank (TA)
=20
=20
=20
From the FLARM manual
=20
=20
=20
"Stealth mode inherently reduces some of the benefits of situation
=20
awareness for yourself and surrounding aircraft. We do not recommend
the
=20
use of Stealth mode, but it is better than turning FLARM=AE off for
tacti=
cal
=20
reasons."
=20
There is no way that the above can be interpreted in any way other than
t=
he
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safety benefits are reduced. Do you really want to be seen being
=20
responsible for telling pilots to reduce safety?
=20
=20
=20
http://www.flarm.com/support/Flarm_Competitions.pdf

It's a matter of how much warning and of what type is useful and
actionable=
.. =20

You have not actually flown with PowerFlarm "radar", have you?

The amount of head down time required to develop any actionable
information=
from present flarm radar screens is scary large. In fact I would argue
th=
at given only flarm/butterfly panel mount displays currently available
we'l=
l be safer with everyone in stealth mode simply because there will be
less
=
to look at on the panel and eyes may stay outside a little more. 3rd
parti=
es will solve the display problem even if Flarm doesn't, but the fact
remai=
ns that radar in open mode shows you mostly targets that are not and will
n=
ever become collision threats.

Read (I tire of saying this) the dataport spec. Page 19. It describes
in
=
detail what stealth mode actually does. Among other things, you'll find
th=
at it still displays all radar targets that might become a collision
threat=
.. I can make the argument that this enhances safety because it does not
so=
clutter the display with non-threats.

Evan Ludeman / T8

No, but I have flown with an LX800, not that this has anything to do with
it at all. I would rather take the advice of the makers of the instrument
and those who have been using FLARM for some time. Stealth mode is no
longer required here for competitions, the full mode can be used. FLARM are
very clear, "We do NOT recommend the use of stealth mode", which part of
that do you not understand. You ignore it at your peril or perhaps more
likely to the peril of others.

The amount of head down time required to develop any actionable information from present flarm radar screens is scary large. In fact I would argue that given only flarm/butterfly panel mount displays currently available we'll be safer with everyone in stealth mode simply because there will be less to look at on the panel and eyes may stay outside a little more. 3rd parties will solve the display problem even if Flarm doesn't, but the fact remains that radar in open mode shows you mostly targets that are not and will never become collision threats.

Evan,

I'm fully with you in that head-down time needs to be minimized.

Just for the record, another possibility to reduce the number of irrelevant
targets on the display is of course to reduce the respective horizontal and vertical ranges. Dangerous targets are not affected by the range setting.

Best
--Gerhard