Probable cause
The loss of engine power due to a loose B-nut on the compressor discharge pressure bleed line.
NTSB analysis
The pilot stated that the helicopter experienced a total loss of engine power while maneuvering during an aerial application operation. He performed a forced landing to a swamp, which resulted in substantial damage to the airframe. Examination of the engine revealed that the compressor discharge pressure bleed line between the governor and the fuel control was leaking at a loose B-nut.
Text from the NTSB. Open the NTSB docket for CEN11LA370 for the full record.
Event
- Date
- May 25, 2011
- Type
- Accident
- Place
- Lakeville, Minnesota
- Highest injury
- Serious
- Serious injuries
- 1
- Weather
- Visual (VMC)
- Light
- Day
Bell 47G-3B-1
- N-number
- N96SH
- Category
- Helicopter
- Damage
- Substantial
- Operating rule
- Part 137 (agricultural)
- Purpose of flight
- Aerial application
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.