Avoid head-on collision? Forward facing LED strobe?

At 23:18 25 July 2012, Dan Marotta wrote:
I recall during WWII, maritime patrol bombers used bright white lights on

their leading edges as camoflage so they could sneak up on U-boats without

being seen. Seems the lights broke up the silhouette.


After a comprehensive study by the RAF it was found that the colour which
was most conspicuous in a wide variety of daylight conditions was black.
The colour which was least conspicuous was, you guessed it, white or light
grey. Strobe lights are not very effective in bright daylight conditions
and when do we do most of our flying? When the sun shines.
There are very good technical reasons why the top surface of a glider must
be white but does the underside have to be?

After a comprehensive study by the RAF it was found that the colour which

was most conspicuous in a wide variety of daylight conditions was black.

The colour which was least conspicuous was, you guessed it, white or light

grey. Strobe lights are not very effective in bright daylight conditions

and when do we do most of our flying? When the sun shines.

There are very good technical reasons why the top surface of a glider must

be white but does the underside have to be?


I recall a similar study by the FAA (which I can't locate at the moment) in which they found white was the color easiest to see against blue sky. White reflects the most light back to the observer.

I would lean towards a white flashing strobe myself. This should be very easy to see.

On Thursday, August 2, 2012 9:59:51 AM UTC-7, tstock wrote:
After a comprehensive study by the RAF it was found that the colour which



was most conspicuous in a wide variety of daylight conditions was black..



The colour which was least conspicuous was, you guessed it, white or light



grey. Strobe lights are not very effective in bright daylight conditions



and when do we do most of our flying? When the sun shines.



There are very good technical reasons why the top surface of a glider must



be white but does the underside have to be?





I recall a similar study by the FAA (which I can't locate at the moment) in which they found white was the color easiest to see against blue sky. White reflects the most light back to the observer.



I would lean towards a white flashing strobe myself. This should be very easy to see.

There are already gliders out there fitted with strobe lights in the vertical fin and wing tips, so it shouldn't be too difficult to do some tests to confirm if it is effective in daylight or not. From what I heard so far, it is not very effective, but I would like to see the results of a more comprehensive study.

Ramy

I had two near misses flying at a place where the Big Sky theory should be working at its best, Ely, NV. One was the closest I have had outside of a contest. Anyone interested can download the IGC files at:

http://www.onlinecontest.org/olc-2.0...l?dsId=2567554
http://www.onlinecontest.org/olc-2.0...l?dsId=2567342

We were both flying near cloud base at the same altitude in opposite directions. The closing rate was 235 kt. The other pilot saw me about 3 sec (22:52:38), or about 1200 ft, before collision and turned to avoid me (I was checking my position on my map and looked up as he was passing me).

This got me to looking into high intensity LED markers. We all are aware of those used by emergency vehicles; they can be seen in bright sunlight at a long distance. I was thinking of mounting one inside the cockpit of my DG400 in front of the instrument pod. I would have to modify the flash circuitry reduce the rate (thereby reducing power consumption). One potential source is:

http://www.extremetacticaldynamics.com/

The cost is a small fraction of a FLARM, and will work with non-FLARM equipped aircraft.

Tom

On Wednesday, August 15, 2012 2:35:18 PM UTC-4, 2G wrote:

We were both flying near cloud base at the same altitude in opposite directions.

This is the scenario that prompted my original post.

On Wednesday, August 15, 2012 2:46:13 PM UTC-4, son_of_flubber wrote:
On Wednesday, August 15, 2012 2:35:18 PM UTC-4, 2G wrote:

We were both flying near cloud base at the same altitude in opposite directions.

This is the scenario that prompted my original post.

I would add that if you're underneath a cloud then you are by definition NOT in direct sunlight and your background in many cases will be a dark cloud. Please post a followup if you install a light.

On Wednesday, August 15, 2012 11:35:18 AM UTC-7, 2G wrote:
I had two near misses flying at a place where the Big Sky theory should be working at its best, Ely, NV. One was the closest I have had outside of a contest. Anyone interested can download the IGC files at:



http://www.onlinecontest.org/olc-2.0...l?dsId=2567554

http://www.onlinecontest.org/olc-2.0...l?dsId=2567342



We were both flying near cloud base at the same altitude in opposite directions. The closing rate was 235 kt. The other pilot saw me about 3 sec (22:52:38), or about 1200 ft, before collision and turned to avoid me (I was checking my position on my map and looked up as he was passing me).



This got me to looking into high intensity LED markers. We all are aware of those used by emergency vehicles; they can be seen in bright sunlight at a long distance. I was thinking of mounting one inside the cockpit of my DG400 in front of the instrument pod. I would have to modify the flash circuitry reduce the rate (thereby reducing power consumption). One potential source is:



http://www.extremetacticaldynamics.com/



The cost is a small fraction of a FLARM, and will work with non-FLARM equipped aircraft.



Tom

The big sky theory does not apply to gliders, this is why we keep having midairs and near misses. Most of us had similar experience at least once. Reason is that gliders congregate in relatively small portion of the sky, especially when cloudstreets are presented, we are all following the same energy lines at the same altitudes, and worth, our eyes are often focused above the horizon to follow the best line.

Please continue your research and post the results. Sometime all it takes is for someone to find an easy solution which works and the rest of us will follow. I am flying for years with reflective tapes on my wingtips but still can't say for sure if it is effective or not, but it doesn't hurt...

Ramy

On Wednesday, August 15, 2012 11:35:18 AM UTC-7, 2G wrote:
I had two near misses flying at a place where the Big Sky theory should be working at its best, Ely, NV. One was the closest I have had outside of a contest. Anyone interested can download the IGC files at:



http://www.onlinecontest.org/olc-2.0...l?dsId=2567554

http://www.onlinecontest.org/olc-2.0...l?dsId=2567342



We were both flying near cloud base at the same altitude in opposite directions. The closing rate was 235 kt. The other pilot saw me about 3 sec (22:52:38), or about 1200 ft, before collision and turned to avoid me (I was checking my position on my map and looked up as he was passing me).



This got me to looking into high intensity LED markers. We all are aware of those used by emergency vehicles; they can be seen in bright sunlight at a long distance. I was thinking of mounting one inside the cockpit of my DG400 in front of the instrument pod. I would have to modify the flash circuitry reduce the rate (thereby reducing power consumption). One potential source is:



http://www.extremetacticaldynamics.com/



The cost is a small fraction of a FLARM, and will work with non-FLARM equipped aircraft.



Tom

Firing off a high intensity strobe inside your cockpit is likely to be extremely distracting to the pilot due to all the canopy reflections. You can try with a decent size photographic flash gun to get some and see how bad it is. In my DG-303 cockpit I would often wear darker trousers and shoes to avoid canopy reflections, so I don't expect this to be a workable mounting location. But mounting LED strobes at the wingtips and pulling wires down the D tube in front of the spar should not be hard. There are already one ASH-31Mi flying in the USA with factory fitted strobe options.

http://www.youtube.com/watch?v=8sbKdSa52sw

Darryl

Firing off a high intensity strobe inside your cockpit is likely to be extremely distracting to the pilot due to all the canopy reflections. You can try with a decent size photographic flash gun to get some and see how bad it is. In my DG-303 cockpit I would often wear darker trousers and shoes to avoid canopy reflections, so I don't expect this to be a workable mounting location. But mounting LED strobes at the wingtips and pulling wires down the D tube in front of the spar should not be hard. There are already one ASH-31Mi flying in the USA with factory fitted strobe options.

Reflections can be eliminated with a reflector that mates to the curvature of the canopy. One could mount it in the nose, but this would involve significant glass work. Another option are aircraft specific LED strobes. I would even put up with the reflections to prevent a mid-air.

Tom

On Wednesday, August 15, 2012 7:02:59 PM UTC-4, Darryl Ramm wrote:

Firing off a high intensity strobe inside your cockpit is likely to be extremely distracting to the pilot due to all the canopy reflections.

This is an obvious concern, but I expect that it all depends on how close the LED is mounted to the inside surface of the canopy and whether you have a shroud closing any gaps.

Mounting in on the vertical stabilizer must have some advantages. Perhaps wider visibility? The youtube link in an earlier post is interesting:

Peter Scholz wrote:

http://www.youtube.com/watch?feature...&v=VRkcJjKEdKE

A solution like this can be integrated into the fin (done at
Schleicher), the additional price will be around 1200 EURO. One glider
at our airport is equipped with this, visibility is excellent.




On Wednesday, August 15, 2012 7:02:59 PM UTC-4, Darryl Ramm wrote:
On Wednesday, August 15, 2012 11:35:18 AM UTC-7, 2G wrote:

I had two near misses flying at a place where the Big Sky theory should be working at its best, Ely, NV. One was the closest I have had outside of a contest. Anyone interested can download the IGC files at:







http://www.onlinecontest.org/olc-2.0...l?dsId=2567554



http://www.onlinecontest.org/olc-2.0...l?dsId=2567342







We were both flying near cloud base at the same altitude in opposite directions. The closing rate was 235 kt. The other pilot saw me about 3 sec (22:52:38), or about 1200 ft, before collision and turned to avoid me (I was checking my position on my map and looked up as he was passing me).







This got me to looking into high intensity LED markers. We all are aware of those used by emergency vehicles; they can be seen in bright sunlight at a long distance. I was thinking of mounting one inside the cockpit of my DG400 in front of the instrument pod. I would have to modify the flash circuitry reduce the rate (thereby reducing power consumption). One potential source is:







http://www.extremetacticaldynamics.com/







The cost is a small fraction of a FLARM, and will work with non-FLARM equipped aircraft.







Tom



Firing off a high intensity strobe inside your cockpit is likely to be extremely distracting to the pilot due to all the canopy reflections. You can try with a decent size photographic flash gun to get some and see how bad it is. In my DG-303 cockpit I would often wear darker trousers and shoes to avoid canopy reflections, so I don't expect this to be a workable mounting location. But mounting LED strobes at the wingtips and pulling wires down the D tube in front of the spar should not be hard. There are already one ASH-31Mi flying in the USA with factory fitted strobe options.



http://www.youtube.com/watch?v=8sbKdSa52sw



Darryl