# NTSB ANC08IA092: Saab-Scania Saab 340B, N364PX, Anchorage, AK, July 29, 2008 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: July 29, 2008, 10:21 local (18:21 UTC) - Place: Anchorage, AK - Coordinates: 61.179443, -149.983337 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.1794&lon=-149.9833&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 9 uninjured - Status: Completed, report March 5, 2009 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 68545 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC08IA092 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68545/pdf - Page: https://openairdocs.org/ntsb/ANC08IA092 ## 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. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (turbine/turboprop): turbine section](https://openairdocs.org/ntsb-findings/01057250): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Saab-Scania SAAB 340B, 1 case](https://openairdocs.org/ntsb-findings/01057250/cases.md?model=7860101), [All aircraft, 74 cases](https://openairdocs.org/ntsb-findings/01057250/cases.md) - [Engine (turbine/turboprop): turbine section](https://openairdocs.org/ntsb-findings/01057250): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Saab-Scania SAAB 340B, 1 case](https://openairdocs.org/ntsb-findings/01057250/cases.md?model=7860101), [All aircraft, 74 cases](https://openairdocs.org/ntsb-findings/01057250/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Saab-Scania SAAB 340B, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=7860101), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Saab-Scania SAAB 340B, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=7860101), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## 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. ## Factual narrative On July 29, 2008, at 1021 Alaska daylight time, the flight crew of a Saab-Scania SAAB 340B airplane, N364PX, aborted the takeoff roll from runway 07R at the Ted Stevens Anchorage International Airport, Anchorage, Alaska, after hearing a "pop" come from the left engine. Peninsula Airways, Inc. operated the airplane under Title 14 Code of Federal Regulations Part 121, as PenAir Flight KS221, a regularly scheduled passenger flight. The airline transport certificated captain, the commercial certificated first officer, 1 flight attendant, and 6 passengers were not injured. Visual meteorological conditions prevailed for the flight to the Aniak Airport, Aniak, Alaska. According to the Director of Operations, the flight crew heard a "pop" prior to rotation and aborted the takeoff. The flight crew noted a momentary over-temperature light, and the captain shut down the left engine. Prior to removal, PenAir maintenance personnel reported that the damage remained contained within the left engine. GE Aviation inspected the engine and reported that one of the stage 1 gas generator rotor blades (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 blade damper binding issue that they have been tracking since 2001. A service bulletin (SB) has been issued (SB 72-0475) to address the gas generator rotor blade damper, and GE Aviation reports on the status quarterly to the Federal Aviation Administration. In part, the SB introduces a blade damper that is not as susceptible to binding. GE Aviation has recommended to the operators that have not complied with the SB to lower the interval of the borescope inspection (BSI) 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 incident. ## Aircraft - Registration: [N364PX](https://openairdocs.org/aircraft/N364PX), registered now, S/N 340B-262 (OpenAirDocs) - Reported make and model: Saab-Scania AB (Saab) SAAB 340B - Registry model: [Saab-Scania SAAB 340B](https://openairdocs.org/model/saab-scania-saab-340b) (registry code 7860101) (OpenAirDocs) - Registry engine: [GE CT7-SER series](https://openairdocs.org/engine/ge-ct7-ser-series) (registry code 30031, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 340B-262 - Engines: General Electric CT7-9B 1750 horsepower turbo prop; General Electric CT7-9B 1750 horsepower turbo prop - Damage: No damage - Flight: Part 121 - Operator: Peninsula Airways Inc, doing business as PenAir - Registered owner: Turbo Lease - Airworthiness certificate: Standard, Transport - Departed: ANC, Anchorage, AK - Destination: ANI, Aniak, AK - Flight plan: IFR - Airport: ANC, Anchorage International, runway 07R, 10,900 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review April 24, 2008; seat: left; flight hours: 15,200 total, 5,100 in this make and model, 222 in the last 90 days, 73 in the last 30 days, 9 in the last 24 hours - Co-pilot; age 27; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review September 7, 2007; seat: right; flight hours: 2,822 total, 1,822 in this make and model, 273 in the last 90 days, 103 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 20,000 ft broken - Temperature: 54 °F, dew point 50 °F - Altimeter: 29.69 inHg - Observed at: ANC From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.