Probable cause
The pilot's improper liftoff technique, which resulted in ground resonance, and the pilot's delayed recognition of the ground resonance.
NTSB analysis
The helicopter began to vibrate as the pilot raised the collective for liftoff. The pilot lowered the collective and closed the throttle when the vibration began; however, he was too late in recognizing the onset of ground resonance, which resulted in a violent, uncontrollable oscillation and separation of the tail boom from the fuselage. Examination of the helicopter revealed no anomalies that would have precluded normal operation.
Text from the NTSB. Open the NTSB docket for CEN12LA247 for the full record.
Event
- Date
- Apr 17, 2012
- Type
- Accident
- Place
- Grinnell, Iowa
- Nearest airport
- Grinnell Regional Airport (GGI)
- Highest injury
- None
- Weather
- Visual (VMC)
- Light
- Day
Hughes 269A
- N-number
- N69HJ
- Category
- Helicopter
- Damage
- Substantial
- Operating rule
- Part 91 (general aviation)
- Purpose of flight
- Personal
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.