Report reveals cause of mishap in F-15 engine

Thursday, Aug. 28, 2003 | 8:51 a.m.

An Air Force accident investigation board has found that $1.6 million in damage done to an F-15E engine during a test in June 2001 at Nellis Air Force Base was caused by the incorrect installation of compressor blade locks.

The Air Combat Command Accident Investigation Board released the report on Wednesday. It was signed by Air Force Col. John S. Clark, president of the board.

There were no other damages to government or private property and there were no injuries.

A Pratt & Whitney engine destined for an F-15E aircraft was sent to the 57th Component Maintenance Squadron at Nellis because damage from a foreign object was suspected.

The 57th wing is responsible for maintaining aircraft and equipment during Red Flag training exercises. The wing also is responsible for Air Force Air to Ground Operations School, air support missions such as Air Warrior, the Thunderbirds and the operation and deployment of the RQ-1 Predator unmanned aerial reconnaissance craft.

Investigators were unable to track the testing or documentation explaining the original engine damage, the report said.

Although technicians could not determine what had damaged the engine, officials decided to rebuild the core module at Nellis.

Investigators said technicians spent 10 months repairing the engine.

In May 2003 a total of four test runs were attempted. On the first three, workers stopped the runs when vibrations in either a gearbox or a fan exceeded limits.

When the fourth test was attempted, airflow through the engine was interrupted, causing it to stall and causing the subsequent engine damage, the report said.

The investigators concluded that blade locks were not properly installed and those conducting the test were over-confident that they had performed the necessary repairs properly.

Such costly incidents are rare in the Air Force, said Capt. Wes Ticer, media relations action officer at Air Combat Command Headquarters.

The mishap was classified as an "A" event, meaning it cost more than $1 million, Ticer said.