Event Details
On July 29, 2008, at 1021 Alaska daylight time, the flight crew of a Saab-Scania SAAB 340B airplane, registration N364PX, aborted the takeoff roll from runway 07R at Ted Stevens Anchorage International Airport, Anchorage, Alaska. The crew heard a "pop" from the left engine prior to rotation and initiated the abort. A momentary over-temperature light was noted, and the captain shut down the left engine. The aircraft, operated by Peninsula Airways, Inc. under 14 CFR Part 121 as PenAir Flight KS221, was on a regularly scheduled passenger flight to Aniak Airport, Aniak, Alaska. Visual meteorological conditions prevailed. The airline transport certificated captain, the commercial certificated first officer, one flight attendant, and six passengers were not injured.
Investigation Findings
PenAir maintenance personnel reported that the damage remained contained within the left engine prior to removal. GE Aviation inspected the engine and reported that one stage 1 gas generator rotor blade (part number 5088T43P05) had separated below the airfoil platform. GE Aviation further reported that the blade separated due to high-cycle fatigue, which is related to a blade damper binding issue that has been tracked since 2001.
Service Bulletin Status
A service bulletin (SB 72-0475) was issued to address the gas generator rotor blade damper, and GE Aviation reports on the status quarterly to the Federal Aviation Administration. The SB introduces a blade damper that is not as susceptible to binding. GE Aviation recommended to operators that have not complied with the SB to lower the interval of the borescope inspection for the "hot" section from 800 flight hours to 400 flight hours between inspections to identify this issue prior to a blade separation. To date, 95 percent of the fleet has complied with the service bulletin. This engine was not in compliance with SB 72-0475 at the time of the incident.