A Teledyne Ryan Global Hawk unmanned air vehicle (UAV) was destroyed in a crash during a test flight at the NAS China Lake test centre on 29 March, just 20min after taking off from Edwards AFB in California.
"We don't know what caused the crash, or any of the specifics regarding the flight test," the USAF says. "We have not retrieved the wreckage yet," adds the manufacturer. The crash is the latest in a series of accidents involving tactical, vertical take-off and strategic UAVs under development for the US armed forces. The Global Hawk has previously suffered only minor technical problems. In September 1998, the first night mission with the system was completed, despite an inflight failure of one of the two integrated mission computers. The UAV's third flight, in May 1998, was marred by a hydraulic pressure loss as the aircraft was on finals to land at Edwards. The gear was deployed with emergency air pressure, but lack of braking caused the drone to overrun the runway surface, causing superficial damage.
The UAV was one of two Global Hawk prototypes taking part in a test programme for the long range high altitude aircraft, which cost over $13 million apiece. The sophisticated aircraft is equipped with infrared and electro-optical sensors, and is capable of maintaining station over a target area 4,800km (2,620nm) from base for over 24h.
Australia is considering buying the Global Hawk. A prototype was due to make a non-stop US-Australia ferry flight next year to take part in Australian trials.
Source: Flight International
