HAMPTON, Va., 30 Aug. 2013. Engineers at NASA's Langley Research Center in Hampton, Va., dropped a former Marine CH-46E helicopter fuselage filled with crash-test dummy occupants and myriad electronics from a height of roughly 30 feet to test improved seats and seatbelts, as well as to gather data related to helicopter crash survivability.
NASA engineers anticipate this rotary-wing research will help make helicopters and other vertical take-off and landing (VTOL) vehicles more serviceable (better able to carry more passengers and cargo), quicker, quieter, safer, and greener—all lending to more extensive use in the airspace system.
"We designed this test to simulate a severe but survivable crash under both civilian and military requirements," explains NASA lead test engineer Martin Annett. "It was amazingly complicated with all the dummies, cameras, instrumentation and the collaborators, but it went well."
They used cables to hoist the helicopter fuselage with its mock passengers into the air and swing it to the ground, much like a pendulum. It was traveling at 30 mph when pyrotechnic devices separated the cables and let the fuselage hit the soil at Langley's Landing and Impact Research Facility.
The fuselage hit the ground hard, observes a NASA representative. Thirteen instrumented crash-test dummies and two uninstrumented mannequin had a rough ride, as did the 40 cameras mounted inside and outside the fuselage. Preliminary observations indicate good data collection, which will take months to analyze.
Researchers used the cameras and onboard computers, with data from 350 instrumentation points, to record every move of the 10,300-pound aircraft and its contents. The helicopter's unusual black-and-white-speckled paint job, related to a photographic technique called full-field photogrammetry, aided in the data collection effort.
"High-speed cameras filming at 500 images per second tracked each black dot, so after everything is over, we can plot exactly how the fuselage reacted structurally throughout the test," explains NASA Test Engineer Justin Littell.
This event marked the first of two planned tests using Navy-provided CH-46E Sea Knight fuselages. A similar helicopter equipped with additional technology, including high-performance, lightweight, composite airframe retrofits, will be used in a crash test next summer. Both are part of the Rotary Wing Project in NASA's Aeronautics Research Mission Directorate.
NASA will use the results of both tests to help improve rotorcraft performance and efficiency. Researchers also want to increase industry knowledge and create more complete computer models that can be used to design safer helicopters.
The U.S. Navy, U.S. Army, and Federal Aviation Administration (FAA) collaborated with NASA on the crash test. For this test, Langley used six of its own crash-test dummies. The Navy contributed the fuselage, seats, crash-test dummies, a mannequin, and other elements of the test. The Army provided a mannequin and a crash-test dummy that simulated a patient lying in a stretcher. The FAA provided a side-facing specialized crash-test dummy and part of the data-acquisition system. Cobham Life Support-St. Petersburg, a division of CONAX Florida Corp., contributed an active restraint system for the cockpit.