For anyone who thinks, in this current U.S. climate of budget restrictions, debt ceilings and sequestration, that it’s a waste of time and/or taxpayer money to drop a helicopter for the sake of science, I beg to differ. The results from a recent helicopter fuselage crash test will yield safety advancements for a number of organizations involved with aviation operations.
NASA teamed with engineers from FAA, the U.S. Navy, Army, and companies from the civil helicopter industry to drop a 45-foot Boeing CH-46 Sea Knight fuselage 30 feet on August 28 at the Langley Research Center in Hampton, Va. The fuselage carried 13 crash dummies, as well as a number of high-speed cameras filming at 500 images per second to record how the fuselage collapses under a crash load.
Lead test engineer Martin Annett noted that NASA is interested in studying airframe crashworthiness “as a whole system, not only the airframe but the seats and the restraints, and there’s lots of development work going on within industry, and DoD, looking at making those types of things safer – energy-absorbing seats, airbags, other materials – but specifically we’re interested in the airframe.” The NASA team wanted to “get a big enough airframe, that could represent anything from medium lift to heavy lift rotorcraft, and things that would be categorized as business jet and above – standard class jets, commuter class jets – in terms of the airframe and the fuselage itself,” Annett said. Once they secured two CH-46 airframes from the U.S. Navy, “we wanted their participation since they pretty much provided everything in terms of seats, airframe, and energy absorbers, so they had first dibs on whatever experiments they wanted to put on board. After that, things just kind of developed. A lot more companies were interested, the Army became interested, and the FAA wanted to look at a lot of different aspects.”
Ultimately, Annett explained, NASA was “hoping to get some of the newer composite aircraft that are of that size, a [Bell-Boeing V-22] Osprey and bigger, but obviously they’re just not available. The Marines are taking the CH-46 out of service and replacing them with the V-22, so they had the airframe available.” He added that it was “relatively close to us in North Carolina” to help keep shipping costs down.
|View of a dummy
through the CH-46
Annett said that there were “on the order of 12 or 13” experiments inside the CH-46 cabin. “It involved things such as restraint systems, standing dummies, side-facing seats that had energy absorbers in them versus the standard troop bench, not only to see how the seats behaved but how the dummies behaved in a side-facing condition.”
According to test engineer Justin Littell, the dots that are painted along the side of the fuselage “are there because we’re trying to track the entire airframe deformation during the impact. So that’s sort of a new experiment we tried, and that seems to be working well.” He added that it’s “going to take a while” to analyze the results of the crash test.
Littell pointed out that for the first time, there were high-speed cameras filming “every dummy that was in the airframe itself,” in addition to the cameras filming outside.
|Modified Boeing CH-46 fuselage crashing
at NASA’s Langley Research Center.
|Dummies inside the cabin following impact.|
“It’s somewhat eye-opening to look at the video,” Annett added, noting that researchers “saw some responses that would cause a lot of severe injury” with dummies in the regular seats, “and then in the dummies that were in energy-absorbing seats, maybe some slight injuries – but again we have to look at all the data and evaluate it against injury criteria, that’s just a first glance.”
For anyone who’s still skeptical: Keep an open mind. Crash tests have led to a number of safety improvements in the automotive industry. Who knows, maybe something learned from this helicopter crash test could save your life, or someone you know, somewhere down the line. Or, at least increase the likelihood of walking away. See more photos and a video of the crash test at www.rotorandwing.com