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NASA Scientists Jubilant After Successful Helicopter Crash
Hugh Pickens DOT Com writes "Elizabeth Barber reports in the Christian Science Monitor that when a CH-46E Sea Knight helicopter plummeted into the ground at more than 30 miles per hour, there was jubilation from the scientists on the ground at the culmination of some two years of preparation to test a helicopter's crashworthiness. 'We designed this test to simulate a severe but survivable crash under both civilian and military requirements,' says NASA lead test engineer Martin Annett. 'It was amazingly complicated with all the planning, dummies, cameras, instrumentation and collaborators, but it went off without any major hitches.' During the crash, high-speed cameras filming at 500 images per second tracked the black dots painted on the helicopter, allowing scientists to assess the exact deformation of each part of the craft, in a photographic technique called full field photogrammetry. Thirteen instrumented crash test dummies and two un-instrumented manikins stood, sat or reclined for a potentially rough ride. The goal of the drop was to test improved seat belts and seats, to collect crashworthiness data and to check out some new test methods but it was also to serve as a baseline for another scheduled test in 2014. 'It's extraordinarily useful information. I will use this information for the next 20 years,' says Lindley Bark, a crash safety engineer at Naval Air Systems Command on hand for the test. 'Even the passenger airplane seats in there were important to us because we fly large aircraft that have the same type of seating."'
In other news, NASA scientists announced confusion after attempting to crash a helicopter and failing despite repeated tries. The helicopter in question had, in various stages, had its stabilizers, fuel tank and even rotors removed. Despite all this, the helicopter remained aloft. "A failure," one scientist was quoted as saying. "We'll just have to shoot it down and try to crash one next next year after more planning." "A helicopter that cannot crash is a tremendous blow to science," another was heard arguing with another, "How are we supposed to obtain crash data with an infinitely levitating hunk of junk?"
If you knew anything about helicopters you'd know that 30mph is VERY relevant. Depending on what you're flying, your load, and weather conditions, 30mph (just over 2600 feet per minute) is approximately the speed you'd hit the ground in an autorotation if you did not flare or try to lessen the rate with only collective (which would not be very effective at all). In some helicopters the vertical descent rate in an auto is much lower but 2600 is a good ballpark number.
Considering the accident rate for helicopters for the last couple years was 4-7 per 100,000 flying hours, while the fatal accident rate was 0.75-1.3 per 100,000, non-fatal accidents are a lot more common than fatal. A large portion of crashes involve take off and landing, or involve slow conditions when moving near the ground (e.g. lifting cargo). 30 mph is also about the speed of decent when in auto-rotation with no forward airspeed (although you could halve that at the minimum decent rate by moving forward). It seems like a 30 mph crash is pretty darn relevant to the real world. Or would you rather they test the effectiveness of seat belts in a crash they were 99% sure would be fatal regardless of seat belts?
If you knew anything about helicopters you'd know that 30mph is VERY relevant.
Indeed. In 1981, I was a young Marine grunt on an exercise in Camp Lejeune, North Carolina. We were riding CH-46s into an LZ and the bird right behind mine lost power and auto-gyrated into the ground. I reached the treeline, and turned just in time to see it hit the ground. The helicopter was badly damaged, and the Marines on board were shaken up, but no one was hurt.
In other news, NASA scientists announced confusion after attempting to crash a helicopter and failing despite repeated tries.
You joke...but this is the sort of thing that never gets funding.
Adam savage tells a tale of how a guy called him after they did the firing bullets inside aircraft episode. He said they'd been trying to get funding to do that experiment for decades.
It also took discovery channel to crash a 'plane and see what happens. There's no way a government could do this...right? (somebody might lose their campaign funding if the results made Boeing look bad!) https://en.wikipedia.org/wiki/2012_Boeing_727_crash_experiment
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