Yehudi Lights

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XB-35

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Hi All,

I'm looking for photographs (and technical drawings) of a Grumman Avenger (and also other aircraft) equipped with these lights (in a concealment experiment against U-boats).

There's an article about this project in an old issue of model aircraft monthly, but no photographs.

According this article, a B-24 Liberator has been also used in these experiments (and on a website article, post-war, a F-4 Phantom with the project name "Compass Ghost")

Does anyone has infos about these secret experiments ?

Thanks for the infos,

All the Best,

XB-35
 
I am sure I saw once (but where) a close-up picture of the nose (cowling) of the TBM but never saw anything on the PBY except the article you refer to.
There has been an intersting article with pictures of the similar experiments done with ships on a canadian website (I cannot recall off-hand the adress of the site but I remember the search I had googlised was about the truth in the Philadelphia Experiment)

JCC
 
The last one is Yehudi Menuhin, the man, which name was used for this project. ;)
 

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Hah! And I always thought it was named after the little guy in the refridgerator that turned the light on & off!


Matej said:
The last one is Yehudi Menuhin, the man, which name was used for this project. ;)
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frank said:
Hah! And I always thought it was named after the little guy in the refridgerator that turned the light on & off!


Matej said:
The last one is Yehudi Menuhin, the man, which name was used for this project. ;)
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Click to expand...

It was according to what I've read.
 
Tophe said:
Funny for a French speaker, but impossible to appreciate for our English friends, Archie...
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Even for French speakers, the near-insult to someone who is dead is rather unsavory ...
 
There was a Nova episode that covered Project Yehudi. I'll take a look through my library and see if I can find it. As I recall there was only one pic of a TBF ashore with a light on the spinner and a couple on the cowl. The did put it to the test on a British APC & it actually worked!
 
Humour, an unknown word for some people...
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The sort of "humour" that manages to be vulgar, to reek in several ways, and to be disrespectful to a dead person, yes certainly it is not for everyone.

Indeed some people enjoy that sort. Those who forgot about the past (or never learnt), and the Le Pen cohorts.
I don't care to be one of those.
 
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Dear Gentlemen,
please try not to go off-topic.
In fact for those who are not French speakers is difficult to understand what you are talking about.

Thanks a lot :)
 
A report in the latest AvLeak implies BAE Systems are experimenting with visual signature reduction on a Hawk, and of course visual stealth was a supposed aim of Boeing's Bird of Prey programme.
 
I made some quick drawing of that visual stealth Hawk. It is part of british "Chameleon" program, allready tested on manned and unmanned planes.
 

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What is the technological basis of Chameleon? Special paintings or coatings, lights...
 
LEDs and LCDs make sense. And actually have the potential for applications on the upper side as well.
 

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For those who want to know more about Project Yehudi, see the article in the Journal of the American Aviation Historical Society, Vol. 15, No. 4 (Winter 1970). Apparently it was successful in that ASW aircraft could get much closer to a surfaced sub before being visually detected, but the advances being made in search radars made the whole approach irrelevant.
 
Hi boys, I never saw an image of the entire Yehudi B-24 but I can post two photographs of details and one about the photocell measuring the color of the light
Nico
 

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Good stuff. Thanks for digging out the pictures and references :)
 
Wow and here I was just about to ask the forum if they had ever heard of the use of the physiological phenomenon termed isoluminance by the USN during WWII, after I stumbled across this Youtube video "Yehudi"
View: http://youtu.be/aIceh3Bk0Cc

And here it is "Project Yehudi"!
A very interesting use of the Mk 1 eyeball wouldn't you agree! And to think that this technology was dropped like a hot potato, with the advent of airborne radar :eek:
Some great find with the Grumman Avenger pics!!

Regards
Pioneer
 
Hmmmm... regarding the video posted by Pioneer, is it possible that the programme it comes from was originally British? In addition to the demonstration of the Yehudi principle being demonstrated on a British FV432 APC, the film showing the attack on the U-Boat seems to show a Short Sunderland...

cheers,
Robin.
 
Yes, originally Canadian Navy, then British, then US.
 
Thanks, Dan_Inbox...

cheers,
Robin.
 
The Yehudi effect can be seen any day on the roads. Oncoming traffic with side-lights / parking lights on tend to 'disappear'. Conversely cars with daylight running lights (which are by necessity brighter), dipped headlights or no headlights can be seen much easier as the dark radiator grille is prominent.

Check it out.

Chris
 
Pioneer said:
And to think that this technology was dropped like a hot potato, with the advent of airborne radar
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Probably more like the advent of defensive search radar on the subs. The point of these lights was not to increase the range at which targets were detected but to decrease the visual detection range of the attacking aircraft. When the subs could use radar to detect an attacker, the theory behind the lights became moot.
 
Deleted the controversial posts of a veeeery long time ago. Better for everybody.
 
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