Probable cause
The pilot's failure to maintain clearance with crops while maneuvering during aerial application.
NTSB analysis
According to the pilot, he had just departed a gravel road (loading zone) to complete an aerial application to an alfalfa field. Shortly after departure, he executed a right turn and one of the helicopter spray booms contacted a stand of 2-1/2-foot-tall alfalfa. The helicopter then began a descending right spin. Subsequently, the spray boom dragged on the alfalfa, resulting a dynamic rollover. The main rotor blades contacted terrain and the helicopter "cartwheeled" onto its left side. Examination of the helicopter revealed damage to the main rotor blades, tail boom, tail rotor, and fuselage. The pilot recommended the following: "Ensure adequate altitude before initiating turns, and exercise more caution when over tall grass or crops."
Text from the NTSB. Open the NTSB docket for CEN10CA251 for the full record.
Event
- Date
- May 15, 2010
- Type
- Accident
- Place
- Baraboo, Wisconsin
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Robinson Helicopter R44
- N-number
- N570MD
- 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.