Probable cause
The pilot’s failure to maintain clearance from transmission wires while maneuvering at a low altitude during an agricultural application flight.
NTSB analysis
The helicopter pilot reported that, while maneuvering at a low altitude during an agricultural application flight, he "forgot to duck" for some nearby transmission wires. The tail rotor struck the transmission wires, and the helicopter impacted terrain.
The helicopter sustained substantial damage to the tailboom.
The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Text from the NTSB. Open the NTSB docket for GAA17CA355 for the full record.
Event
- Date
- Jun 21, 2017
- Type
- Accident
- Place
- Williams, California
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Bell UH1B
- N-number
- N6180A
- Category
- Helicopter
- Year built
- 1962
- 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.