Probable cause
A total loss of engine power due to the improper assembly of the compressor discharge tubes to the combustion liner.
NTSB analysis
The helicopter was performing low-level external-load (saw) tree trimming operations when the engine lost power and the helicopter subsequently descended into trees and terrain. Detailed examination of the engine revealed evidence of an improper assembly of the compressor discharge tubes to the combustion liner, and evidence of an improper interim repair. Further metallurgical examination of the combustion section revealed evidence of non-uniform combustion patterns, and a subsequent distortion of the materials, which ultimately resulted in rubbing of the first stage turbine wheel and failure of a turbine blade in high cycle fatigue.
Text from the NTSB. Open the NTSB docket for ERA09LA031 for the full record.
Event
- Date
- Oct 30, 2008
- Type
- Accident
- Place
- Carroll Township, Pennsylvania
- Highest injury
- Serious
- Serious injuries
- 1
- Weather
- Visual (VMC)
- Light
- Day
Hughes 369D
- N-number
- N606AS
- Category
- Helicopter
- Damage
- Substantial
- Operating rule
- Part 133 (external load)
- Purpose of flight
- Other work use
From the NTSB aviation accident database: N-registered aircraft, events since 2008, data through Oct 28, 2026. The file is published monthly, so the latest weeks are incomplete and recent records can change. The official source is the NTSB aviation investigation search. CheckAero is independent and not affiliated with the NTSB.