Introduction
A United States Air Force B-52H Stratofortress, operating under call sign 'Raider 21', crashed into the Pacific Ocean approximately 50 kilometers north of Guam Island on a flight that was part of the Guam Liberation Day celebrations. The aircraft had departed from Andersen Air Force Base with six crew members aboard. All six were killed in the crash.
Flight Details
The flight was initially normal. About 15 minutes after takeoff, while descending from 14,000 feet to 1,000 feet, the bomber became uncontrollable and crashed. The aircraft disintegrated upon impact, and only a few debris were recovered. The crew consisted of Maj Chris Cooper (pilot), Cpt Michael Dodson (copilot), 1st Lt Robert Gerren (electronic warfare officer), 1st Lt Joshua Shepherd (navigator), Maj Brent Williams (radar navigator), and Col George Martin (flight surgeon).
Investigation Findings
The Air Force accident investigation board released its report on February 13. Due to the absence of a flight data recorder, investigators reconstructed the events from air traffic control radar data and parts recovered from the ocean floor by remote-controlled Navy submarines. A critical recovered component was a jackscrew that controls the rear stabilizers. It indicated that the stabilizer trim was set at 4.5 to 5 degrees nose down, but parts that could explain why the stabilizers were pointed down were not recovered.
Based on flight simulations, the board determined that the flight was normal until the jet turned left and began descending about 33 miles west of Guam. As the 48-year-old bomber descended at over 240 mph, the stabilizers suddenly malfunctioned, putting the aircraft into a dive with the nose pointed down 30 degrees or more. One of the pilots likely attempted to manually level the stabilizers using a control wheel that moves the stabilizer 1 degree every two to three seconds, but there was insufficient time due to the low altitude.
At least three crew members attempted to bail out seconds before impact, but the aircraft's speed, altitude, and angle made survival impossible.
Probable Cause
The investigation board concluded that malfunctioning parts and late recognition of spiraling problems likely caused the crash. The specific problem was identified as the rear stabilizers, though the root cause of the stabilizer malfunction could not be determined. Board president Brig. Gen. Mark Barrett stated that even an experienced aircrew would have found it difficult to recognize, assess, and recover from the rapidly developing situation.