Boeing last month halted flight tests of its optimum-speed-rotor drone while it investigates the latest crash of the aircraft type.
The turbine-powered A160T Hummingbird unmanned air vehicle crashed Dec. 10 during a flight test from Boeing Advanced Rotorcraft Systems’ facility in Victorville, Calif., about 50 nm northeast of Los Angeles.
The aircraft was flying at about 2,300 ft agl, or 5,000 ft msl, when it crashed. The drone was destroyed in the crash.
Boeing had resumed flight tests of the A160 14 months ago follow 15-month hiatus after a crash. The previous crash was the aircraft’s third in 36 flights.
The company has been extending the endurance/payload envelope of the Hummingbird since one carried 1,000 lb for 8 hr on Sept. 27, 2007. The turbine version of the A160 first flew in June 2007. The A160T is powered by a Pratt & Whitney Canada PW207 turboshaft.
The Hummingbird’s optimum-speed rotor design slows the rigid, hingeless main rotor during various phases of flight to minimize power required to drive that rotor. That is intended to improve the helicopter’s fuel efficiency, reduce noise emissions, and extend rotor, transmission, and engine lives.
Development work on the unmanned helicopter has been funded by the US Defense Advanced Research Projects Agency and Special Operations Command.