SAAB 340B N364PX incident near Anchorage, Alaska

Probable cause

The failure of one of the stage 1 gas generator rotor blades due to high-cycle fatigue, resulting in a contained engine failure during the takeoff roll.

NTSB analysis

During the takeoff roll, the flight crew of the 14 Code of Federal Regulations Part 121 scheduled passenger flight heard a "pop" coming from the left engine. The takeoff was aborted and the airplane returned to the gate. Maintenance personnel noted that the left engine had a contained engine failure. During the manufacturer's inspection of the engine, they noted that one of the stage 1 gas generator rotor blades had separated below the airfoil platform as a result of high-cycle fatigue. The manufacturer reported that the failure is related to a blade damper binding issue that has been tracked since 2001; Service Bulletin (SB) 72-0475 was issued to address the gas generator rotor blade damper. The manufacturer also recommended that all operators who have not complied with the SB lower the borescope inspection for the hot section from 800 to 400 flight hours. The manufacturer says that to date 95 percent of the affected fleet comply with the SB. The incident engine had been borescoped within the last 400 hours.

Text from the NTSB. Open the NTSB docket for ANC08IA092 for the full record.