Lockheed Martin has confirmed that its P-175 Polecat unmanned air vehicle crashed in December on the Nevada test range after the unintentional activation of its flight termination system.

The Skunk Works-built private-venture high-altitude UAV demonstrator, first flown in secret in 2005 and unveiled at last year’s Farnborough air show, had only recently returned to flight.

The tailless flying-wing UAV was “damaged beyond repair due a failure of the flight-termination ground equipment, which caused the aircraft’s fail-safe flight termination mode to activate”, says Lockheed, adding that the automatic fail-safe system was “designed to irreversibly terminate flight” so that the UAV did not leave the range.

Polecat Lockheed Martin W445

Lockheed says the UAV was “functioning normally, performing well and in full positive control by the ground operators” when the failure occurred.

According to Lockheed, it was ordered by the US government not to discuss the 18 December accident until after an investigation was completed. "There was an irreversible unintentional failure in the flight termination ground equipment at the Nevada Test and Training Range. We believe the test range has corrected the potential for a similar circumstance to occur again," the company says.

Powered by two Williams International FJ44 turbofans, the 4,100kg (9,000lb) gross-weight Polecat was a low-observable, high-latitude UAV designed to demonstrate a number of advanced technologies, including low-cost composite construction and laminar-flow swept wing.

Source: FlightGlobal.com