Strobe light on glider

A while ago several people remarked that Schleicher gliders offer a strobe was an option.

Below is an URL to a youtube video of such strobe. Typically the strobe is coupled with an unit from LxNav that allow the strobe to be on, only flash with Flarm warning, or off.

https://www.youtube.com/watch?v=XMdGXX11Bs4

On Monday, January 23, 2017 at 8:58:52 PM UTC-7, Jonathan St. Cloud wrote:
A while ago several people remarked that Schleicher gliders offer a strobe was an option.

Below is an URL to a youtube video of such strobe. Typically the strobe is coupled with an unit from LxNav that allow the strobe to be on, only flash with Flarm warning, or off.

https://www.youtube.com/watch?v=XMdGXX11Bs4

Thanks Jonathan for posting this. I have tried to find a simple LED strobe that I could attach to the glider that would use self-contained battery power. perhaps one on the bottom of fuselage and another behind the canopy. I have done a bit of searching on the web trying to find something - but haven't seen anything yet. If anyone is aware of such an device - would appreciate the info.

Thanks Jonathan for posting this. I have tried to find a simple LED
strobe=
that I could attach to the glider that would use self-contained battery
po=
wer. perhaps one on the bottom of fuselage and another behind the canopy.
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have done a bit of searching on the web trying to find something - but
hav=
en't seen anything yet. If anyone is aware of such an device - would
apprec=
iate the info.


Link here for a strobe that fits to the canopy

http://www.how2soar.de/index.php/led...d-rechenknecht

Not to be a Debbie Downer, but in the previous discussion of glider strobes it was pointed out that battery powered strobes don't have the power to be conspicuous against a bright sky.

Even high-powered airliner strobes don't grab your attention during the day.. There's a 737 that usually flies over my house at roughly 2,000 AGL. The plane itself is easy to see, but at closest approach his wing tip strobes are barely visible during the bright conditions typical of a soaring day.

-John, Q3

Hi Debbie: I do not know if any studies have been done as to the visibility, but a strobe that is 12 long does put out more of a visual signature than a single point of light, as on most powered aircrat. Imagine, not a bright sky but running under a (dark developed )cloud street at 110 knot IAS at 17,000 ft with another glider flying in opposite direction, same speed. The Flarm goes off and so does the strobe, will that 12 inches of strobe give off enough to catch the eye of the other pilot? That strobe sure is bright, and I have had people tell me that it really stands out. It seems as if the 12 inches of strobe is much more visible than a single point of light.


On Tuesday, January 24, 2017 at 5:53:24 AM UTC-8, John Carlyle wrote:
Not to be a Debbie Downer, but in the previous discussion of glider strobes it was pointed out that battery powered strobes don't have the power to be conspicuous against a bright sky.

Even high-powered airliner strobes don't grab your attention during the day. There's a 737 that usually flies over my house at roughly 2,000 AGL. The plane itself is easy to see, but at closest approach his wing tip strobes are barely visible during the bright conditions typical of a soaring day.

-John, Q3

Jonathan, I do understand your concern. I've seen the fin strobe on an ASG-29 several times, once at Mifflin running ridges on an showery, overcast day with him coming towards me. The strobe was visible, but not that helpful IMHO until he was quite close, and by then I'd already seen the plane itself because of Flarm. YMMV, of course, so my best advice is for you is to do the experiment. Set one up along a straight road on a gloomy day and figure out the distance when it becomes obvious.

-John, Q3

On Tuesday, January 24, 2017 at 11:15:27 AM UTC-5, Jonathan St. Cloud wrote:
Hi Debbie: I do not know if any studies have been done as to the visibility, but a strobe that is 12 long does put out more of a visual signature than a single point of light, as on most powered aircrat. Imagine, not a bright sky but running under a (dark developed )cloud street at 110 knot IAS at 17,000 ft with another glider flying in opposite direction, same speed. The Flarm goes off and so does the strobe, will that 12 inches of strobe give off enough to catch the eye of the other pilot? That strobe sure is bright, and I have had people tell me that it really stands out. It seems as if the 12 inches of strobe is much more visible than a single point of light.

I remember watching a documentary on WWII camouflage techniques and am reminded of one counter-intuitive technique that actually used bright lights in daylight to make equipment on the horizon visually disappear. I often ponder the true effectiveness of running with lights on in small powered planes during the day and whether there have been any studies to support the validity of this practice.

Now, you've got me wondering about the effectiveness of bright strobe strips during daylight flights.

Hmmm...

Paul A.
Treasure Coast Soaring Club
Vero Beach, FL

My Google Fu is strong today. I found a Wiki page about the use of counter-illumination for camouflage that was quite interesting to read.

en.m.wikipedia.org/wiki/Yehudi_lights

From what I'm reading, the brightness of the strobes could work against you as counter-illumination if they are not significantly brighter than the surrounding sky. On a bright, blue sky day, would a bright strobe strip help or hurt your visibility. As I said in my previous post...counter-intuitive....

Paul A.
Treasure Coast Soaring Club
Vero Beach, FL
@TCSoaring on Facebook

Don't have the energy (ha) today to do a detailed read, but something like this should give some clue:

http://www.imedpub.com/articles/avia...visibility.pdf

One sentence early on reads: "It is stated that an intensity of 350 cd is required for a signal light to be
visible from 0.125 miles away in conditions corresponding to a runway visual range of 0.125
miles".

So, 1/8 of a mile requires 350 Candela (in a runway setting, where there might be more contrast with ground items?) We probably want 1 mile ideally? So, some math converting Candela to Lumens (which is what is reported in the specs for strobes) would get you some rough approximation of the lumens required to be visible over some reasonable angle (steridians). A very quick back of the envelope tells me that a bike strobe (typically 200-400 lumens) is several orders of magnitude too weak to be useful. Maybe someone has the time to run numbers and make sure I didn't add when I should've divided etc.

P3

Yehudi lights are to make a dark airplane blend into bright sky. A glider is not very dark. I certainly have no ownership in strobes, while not a cheap option, I have had enough close calls and one paint scrape, that I have a Flarm, Mode-S, strobe and 20-15 vision. If you hit me I will be ****ed! While I have not seen a strobe equipped glider, except for one N4DM that had a strobe mounted on turtle deck, I could certainly see that flash, but I could see the 26.5 meter wings too. I do know that anything unusual can get your attention, like a glint of reflection, a strobe, a maneuver etc. It is hardly worth debating the merits without empirical data and test assumptions. I merely posted the video. On ground if I turn on my strobe in very bright light it really shows well and as I said others say it is bright, have o idea if they see the strobe or glider first. I do know added high visibility devices does not hurt your visibility.


On Tuesday, January 24, 2017 at 10:20:29 AM UTC-8, Paul Agnew wrote:
My Google Fu is strong today. I found a Wiki page about the use of counter-illumination for camouflage that was quite interesting to read.

en.m.wikipedia.org/wiki/Yehudi_lights

From what I'm reading, the brightness of the strobes could work against you as counter-illumination if they are not significantly brighter than the surrounding sky. On a bright, blue sky day, would a bright strobe strip help or hurt your visibility. As I said in my previous post...counter-intuitive...

Paul A.
Treasure Coast Soaring Club
Vero Beach, FL
@TCSoaring on Facebook