August 3, 2001 (by Lieven Dewitte) - Catastrophic engine failure caused the April 3 crash of a U.S. F-16DJ fighter near Misawa Air Base, Air Force investigators concluded.
A blade from the third stage compressor came loose, puncturing the engine's compressor section, preventing 1st Lt. Mark Hadley from restarting the engine, according to an accident investigation board report released Wednesday.
In the report's executive summary, accident board president Col. John Gibbons of Hickam Air Force Base, Hawaii, said damage to blade No. 30 of the engine’s third stage compressor caused it to tear and bend.
It was unknown when this damage occurred; however, it started a chain of events that remained undetected.
Because of its location within the engine, Gibbons said that a complete teardown of the engine would have been necessary to discover it. Due to the location of the internal damage, maintenance specialists had no indication that an engine teardown was warranted.
While in-flight April 3, a portion of the blade separated and lodged itself in the engine's compressor case, the report states.
Blade friction caused a titanium fire that burned through a portion of the compressor section, preventing normal engine operation.
Hadley, a pilot with the 13th Fighter Squadron, ejected from the crippled fighter over Ripsaw Range, 13 miles north of Misawa in northern Japan. He sustained minor injuries.
Gibbons concluded Hadley's decision to eject was "prudent, proper and correct."
The $19.8 million aircraft was destroyed after it crashed into the Pacific Ocean in about 20 feet of water.
An unknown foreign object damaged the aircraft's single General Electric F-110-129 engine, the report stated.
Foreign object damage is a generalized term for something that causes damage - from a forgotten tool or an excess part overlooked by maintenance workers, to something ingested through the jet's intake, such as a bird.