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DavRedf

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I just came across this and cracked up so I had to show it here.

David

Scientists at NASA have developed a gun built specifically to launch dead chickens at the windshields of airliners, military jets and the space shuttle, all traveling at maximum velocity.
The idea is to simulate the frequent incidents of collisions with airborne fowl to test the strength of the windshields.

British engineers heard about the gun and were eager to test it on the windshield of their new high speed trains. Arrangements were made. But when the gun was fired, the engineers stood shocked as the chicken hurtled out of the barrel, crashed into the shatterproof shield, smashed it to smithereens, crashed through the control console, snapped the engineer's backrest in two and embedded itself in the back wall of the cabin.

Horrified Britons sent NASA the disastrous results of the experiment, along with the designs of the windshield, and begged the U.S. scientists for suggestions.

NASA's response was just three words, "Thaw the chicken."
 

wwattles

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Here's a more complete version of the story from the urban legend archives...

Catapoultry

WW
 

mikeyd

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Sure was, and if I recall correctly, it did not matter, as the mass was the same with a frozen or thawed chicken. However the Beechcraft windscreen they used was not bird rated!
 

Ryan S.

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mass was the same but with a thawed chicken, the pressure would probably be less and it might work.

anyway ccool story.
 

bobkrech

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The USAF "chicken gun" is located at the Arnold Engineering Development Center on Arnold Air Force Base in Tellahoma, Tennessee. It is one of several special guns developed at the AEDC VonKarman Facilities to study high velocity impact phenomenon.

Arnold's a great place to do research and I spent 13 weeks there in 1979 using G-range to study hyperverlocity impact phenomon. I also did a few tests on S-1 which is in the same building as the "chicken gun" which is is formally known as S-3 The Bird Impact Facility. It can launch a 4 pound chicken or similar projectile at speed to Mach 1.4 to test aircraft component impact strength. The chickens are purchase from a local farmer, asphixiated, stored frozen and thawed to 70 F before the test.

You don't want to fire a frozen bird because it comes out of the gun about 10% faster than the thawed bird, and with 21% higher kinetic energy than anticipated, will go through the test object. And yes, it happened once. Only once.

I've download an interesting article about the chicken gun and abstracted the "meat" from an USAF press release from https://www.arnold.af.mil/aedc/newsreleases/1998/98-149.htm

In an industry where technology is vital to providing accurate aerodynamic data, the means used by AEDC’s Bird Impact Facility are quite surprising to visitors, said Randall Watt, an AEDC project manager in the facility . "They expect a more sophisticated test technique, but it’s really common sense, a very simple thing," he said. "If you are trying to simulate a bird hitting the windshield of an aircraft, the easiest and best way to do it is to catch a bird, accelerate it to the desired speed and have an aircraft windshield in its path."

Four-pound chicken carcasses are launched at a target at speeds to simulate a direct bird-strike encounter at in-flight conditions. This method of operation led to the facility’s nicknames, the "Chicken Gun" or the "Rooster Booster."

According to Watt, the Vietnam War prompted the need for the development and operation of the Chicken Gun. During the height of the war, the F-111 aircraft was equipped with terrain-following radar that allowed the aircraft to fly along a few hundred feet off the ground resulting in collisions with many birds. Thousands of aircraft and bird collisions occurred annually, some resulting in extensive damage to the aircraft and serious injuries to its crew. The worst scenario ended in a fatality.

An office at Wright-Patterson AFB was charged to do something about the bird-impact hazard.

"Familiar with AEDC’s range gun experience, they asked AEDC what it would take to develop some sort of bird-strike test," Watt said.

Using some scrap hardware, including an old 8-inch Naval gun, and a little design and fabrication, AEDC engineers assembled a simple air gun. The first shot was on Sept. 14, 1972, and calibration shots continued until Nov. 29 when the F-111 crew escape module was tested.

Since its debut, the Chicken Gun has tested various components like wings, tail sections, windshields and canopies of a majority of aircraft flying in the Defense Department’s inventory.

The official Air Force bird strike qualifying testing center, AEDC’s Chicken Gun has bird-strike certified components of aircraft including the A-7, A-10, B-1, F-4, F-15, F-16, A-18, T-37, t-38, T-46 and T-6A.

But, the Chicken Gun doesn’t always launch chicken carcasses. Other projectiles have been used to simulate in-flight bird-strikes, including spheres, gelatin birds, wet rags, DuxSeal, quails, a sirloin tip roast and rolled rib with chicken bones.

Although the American society for Testing and Materials Standard for bird-impact testing allows the use of imitation birds, the Air Force requires use of a real bird carcass.

As for the choice being the chicken, "The chickens are provided by a local chicken farmer, and they are accessible," Warren Shells, Sverdrup Technologies project manager, said.

Both Shells and Watt said the best thing to use to simulate a bird strike is a bird because it keeps the event as close to reality as possible.

For those of you with inquiring minds, check out the facilities at

https://www.arnold.af.mil/aedc/factsheets/aedc/AEDC.pdf

Bob Krech
 

sandman

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Bob,

Gee, that's very very informative....

But...just not as funny as the frozen chicken thing!

sandman:D
 

Stones

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Originally posted by bobkrech
...
Both Shells and Watt said the best thing to use to simulate a bird strike is a bird because it keeps the event as close to reality as possible.
...
Bob Krech
Well...except for the fact that they're already dead...yea. ;)
 

bobkrech

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Originally posted by Stones
Well...except for the fact that they're already dead...yea. ;)
Yeah, but the difference is only a millesecond or so.

Bob Krech
 

DavRedf

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But just imagine the look on the chickens faceif it were still alive.
0 to mach 1.4 in less time than it takes to s**t.
I bet it would outfly its feathers.

David
 

Micromeister

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Do you know the last thing that bird or the bugs hitting your windsheld will see?
It's butt:D
 

Neil

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Man, that one with the cat is HILLARIOUS!:D Poor kitty, though...

I gotta get me an airgun like THAT... Mach 1.4... I thought my 750FPS gun seems wimpy now...:D
 

Mike

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Originally posted by bobkrech
Both Shells and Watt said the best thing to use to simulate a bird strike is a bird because it keeps the event as close to reality as possible.
So much for reality...when was the last time you saw a chicken fly? :D
 

Elapid

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back in college, there was this guy (with a BS in Physics) that figured out that the resultant splat seemed too large for the size of the original insect. what he came up with was rather interesting. he figured out that the hard-shelled bugs don't equalize pressure very rapidly since their typical flights are quite controlled. the windshield of a moving car has a low pressure zone due to the rapidly moving (from the car's frame of reference) film of air.

well, to get to the point, the insects explode before they hit the windshield!

maybe i could set up a device to test this in a lab setting...
vacuum pump, solenoid valve, clear plastic tube, video...
how demented is that!
 
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