Probable cause
The pilot's failure to maintain clearance from the wire.
NTSB analysis
The pilot reported that during an aerial application flight, he was paralleling a highway as he was applying chemical to a cornfield. He gained altitude to clear a homestead and then descended into the field to continue spraying. He reported that the helicopter impacted an unmarked wire that was strung diagonally between the road he was paralleling and the corner of the property. The helicopter impacted the field and the main rotor blades separated from the airframe, causing the helicopter to cartwheel prior coming to a stop. The helicopter sustained substantial damage to the main rotor blades and fuselage. The pilot reported that there was no mechanical malfunction or failure of the helicopter prior to the wire strike.
Text from the NTSB. Open the NTSB docket for CEN11CA535 for the full record.
Event
- Date
- Aug 1, 2011
- Type
- Accident
- Place
- Joice, Iowa
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Texas Helicopter Corp OH-13H/M74A
- N-number
- N51857
- 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.