Stabilizer Trim Felled B-52

An improper stabilizer trim setting caused the crash of a B-52 near Guam last July, an Air Force accident investigation board reported Friday. Brig. Gen. Mark Barrett, commander of the 1st Fighter Wing at Langley AFB, Va., and president of the AIB, told reporters in a conference call that the trim was set between 4 to 5 degrees nose down when the bomber crashed, killing all six aboard. He judged it was most likely a mechanical malfunction, but couldn’t absolutely rule out pilot error. The wreckage, in 12,000 feet of water, couldn’t be fully salvaged, but analysis of some recovered stabilizer parts confirmed what the AIB deduced from computer modeling and simulations. The models were based on radar and transponder data. The B-52 simulator eliminated practically any other reason for the crash, Barrett said. That the aircraft was at low altitude and in a descending turn when the problem manifested and the crew’s “late recognition” of what was happening were contributing factors. There are emergency procedures for just such a contingency, which Barrett called “very rare” in the B-52, and the crew apparently began applying them at 10,000 feet, but “they just ran out of time,” Barrett said. There was “nothing amiss” in preflight checks, he said, adding he didn’t believe the crew unintentionally caused the problem because of their level of experience. (Also read ACC release)