NORFOLK, Virginia — NASA engineers will crash a former military helicopter on Wednesday that's been retrofitted with a variety of composite subfloors to see how the material affects the likelihood of injuries.
Interest in using carbon composites in airframe design has grown because it is a lightweight material, but NASA officials say there hasn't been a lot of safety testing done on a full-scale level.
"One of the things that concerns me with carbon composites is how crashworthy it is, and knowing that, what is it you can do within future designs that will give you both - that you still have all the added benefits of reduced weight and still, will it be reliably crashworthy?" said Martin Annett, the lead test engineer for Wednesday's test. "That's really been the drive for NASA here to look at those types of designs."
The full-scale crash test will occur at NASA's Langley Research Center in Hampton, where a former Marine helicopter airframe will be swung from cables like a large pendulum at a slight angle and then released so it can free fall and slam into a pile of soil at 30 mph. Officials say the impact is representative of a severe but survivable crash under civilian and military requirements.
NASA is collaborating with the Navy, Army, Federal Aviation Administration, the German Aerospace Center and the Australian Cooperative Research Center for Advanced Composite Structures on the test.
"The Navy is acutely interested in how well the composite underfloor structure behaves," said Lindley Bark, Naval Air Systems Command's crash safety engineer.
"I expect to use this data for the next 10 to 20 years."
A similar crash test was conducted last summer, although the composite material was not used. Officials say this fall's test with a CH-46 Sea Knight is based, in part, on what they learned last year. Bark said the Navy is gathering so much data from the crash test that it will take several months to analyze all of it, but that the lessons learned from it could be applied shortly after that.
One of the experiments the Navy is testing has to do with crash recorders being placed in various locations within the helicopter, which could allow investigators to analyze that data instead of having to reconstruct crashes.
Three energy-absorbing composite subfloor concepts will be tested. NASA says nearly 40 cameras inside and outside the helicopter will record how 13 data-recording crash test dummies and two mannequins react before, during and after impact.
NASA says it will use the results of the crash test to improve rotorcraft performance and efficiency. Researchers also want to create better computer models that can be used to design safer helicopters.
Both tests are part of the Rotary Wing Project in the Fundamental Aeronautics Program of NASA's Aeronautics Research Mission Directorate.
Brock Vergakis can be reached at http://www.twitter.com/BrockVergakis
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