06 June 2008

First Crash of a B-2 Bomber in Guam on 23 February 2008

On 23 February 2008, a B-2 bomber from the 509th Bomb wing of Whiteman AFB, MO, crashed while taking off from Andersen AFB in Guam. Both pilots successfully ejected, sustained only minor injuries. injuries to his left arm and shoulder.

The investigation concluded that water distorted preflight readings in three of the plane's 24 sensors, making the aircraft's control computer force the B-2 to pitch up on takeoff, resulting in a stall and subsequent crash. The sensors measure air pressure to help calculate everything from airspeed to altitude. Because of the bad data, flight computers had inaccurate airspeed and wrongly indicated a downward angle, which contributed to an early rotation and uncontrolled 30-degree pitch up.

The executive summary of the accident report stated that a technique developed two years prior to the crash, but at the time of the accident not widely known in the B-2 community, probably would have prevented the crash. The technique essentially heats the sensors and evaporates any moisture before data calibrations. The technique was never formalized in a technical order change or captured in 'lessons learned' reports, so only some pilots and some maintenance technicians knew of the suggestion.

Maj. Gen. Floyd L. Carpenter, who headed an accident investigation board, stated that the crash probably could have been avoided if knowledge of a technique to evaporate the moisture had been disseminated throughout the B-2 program. General Carpenter said procedures and policies are now in place to guard against similar crashes.

The accident aircraft had been in service since 1995, and was expected to remain in service for another 50 years. This was the first crash of a B-2, and there are now 20 aircraft left in the fleet.

The video that was produced by Glenn Pew includes the takeoff and crash sequence, and also shows a reconstruction of the event, using computer animation based on data from the flight.

Crash Video and Computer Reconstruction