Washington, July 4 (IANS): NASA has crashed a plane in controlled conditions, to test the efficacy of emergency locator transmitters (ELTs).

ELTs are supposed to automatically transmit distress signals to satellites after an aircraft accident. But in most cases they fail because of inadequate performance specifications.

"So, NASA's here to innovate that technology, which will ultimately improve the probability of a successful rescue," said SAR mission manager Lisa Mazzuca.

"It's not obvious to the public what NASA does with search and rescue," Mazzuca, referring to NASA's role in improving aviation safety, was quoted as saying by Engadget.

For the crash test, NASA used three old Cessna 172s. Four brand new ELTs were loaded on the planes to see if they would deploy automatically and resist fire, shock and vibration.

The planes made simulated hard landings from a huge gantry at NASA's Langley Research Centre in Virginia.

The whole thing was captured by 64 channels of sensor data and as many as 40 cameras inside and outside the plane.

According to early results, only one of the four devices transmitted within 50 seconds of the crash, though the rest did trigger a short time later.

NASA will now try to figure out why the ELTs performed that way and will subsequently follow up with further drop tests.