Early in July, 16-year-old Autumn Veatch was found on the side of a Washington state highway. She told the people who picked her up that she had been walking for days since the Beech A-35 she was flying in with her step-grandparents flew into a bank of clouds and then crashed in the wilderness. The plane caught fire; only Veatch was able to escape.
Veatch's own story is remarkable, but even more remarkable is that even in this extremely connected world with satellites and a survivor to guide the search teams, it still took days to find the crash site.
All planes are required to have Emergency Locator Transmitters (ELTs), according to the Washington State Department of Transportation. In the days following the wreck, search teams flew over great swaths of wilderness listening for beacon signals. They eventually found the plane in “extremely rugged and vertical” terrain in the words of the Skagit County Sheriff's Office. It's unclear whether the plane's ELTs contributed to its discovery.
Meanwhile, as Veatch's story unfolded, NASA was in the middle of a project that had it purposely crashing Cessna 172s at the Langley Research Center in Hampton, Virginia. Hoisting the planes 80 to 100 feet in the air, the researchers let them go, watching them come in for a very hard landing.
The research is ongoing, and although it may look like wanton destruction, the crashes have a purpose: NASA is testing ELTs like the ones that should have worked on the plane Veatch was in. The hope is to improve the devices' performance in critical situations. According to NASA, "ELTs are supposed to transmit the distress signal within 50 seconds of an airplane crash. Current models send the signal to an orbiting satellite, which then gets repeated to the nearest Search and Rescue (SAR) ground station. That data is used to compute with a location, which is sent to rescue personnel."
However, "Too often they [ELTs] fail to work as expected, in part because of inadequate performance specifications in several areas including vibration, fire survivability, automatic activation, crash safety, and system installation," said Chad Stimson, NASA Langley Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project manager.
The first crash test in early July outfitted a 1958 vintage Cessna with four new ELTs, as well as a host of sensors and cameras. NASA researchers crashed that plane onto a concrete strip and found that “only one of the four transmitters went off and started sending location signals within the first 50 seconds. The others triggered a short time later.”
The second crash test aimed a similarly outfitted Cessna at a patch of soft dirt. That crash was much more dramatic than the first—the plane flipped over, the wings were destroyed, and the windshields shattered. Stimson told NASA that this more dramatic destruction occurred because small aircraft tend to skid on concrete, dissipating energy. But on dirt, a plane will often feel the full force of its fall.
The ELTs during the second crash test fared a bit better than during the first. In an e-mail to Ars, a NASA representative wrote, “Four of the ELTs operated during the crash and transmitted to space. They are still functional. The status of the 5th ELT is currently under investigation and no conclusions have been drawn yet.”
NASA also said that data gathered from the tests would help researchers learn how best to install ELTs and how to manage their distress signals. "Current ELTs transmit on the internationally protected 406 MHz bandwidth for SAR,” the NASA representative added. “They also broadcast a swept tone on 121.5 MHz to support local homing, but the satellites do not process those transmissions. NASA is working on a new generation of beacons that includes ELTs. The new beacons will greatly improve our ability to identify and locate people in distress.”
A final test will be executed in August. Until then, check out some cool photos from NASA's crashes below.
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Drop test of a Cessna aircraft.
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Listing image by NASA Langley
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