Accident
On April 17, 2012, at approximately 1116 central daylight time, a Hughes 269A helicopter experienced ground resonance during takeoff at Grinnell Regional Airport in Grinnell, Iowa. The pilot aborted the takeoff. The helicopter sustained substantial damage to the fuselage. The commercial pilot and a passenger were uninjured.
Aircraft and Flight
The helicopter, registration N69HJ, was registered to Lowry Flying Service Inc and operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan had been filed for the local flight that was originating at the time of the accident.
Pilot Actions
According to the pilot, when he raised the collective for liftoff, the helicopter began to vibrate. He "rolled the collective down" and "throttle off," but it was too late, and the helicopter "shook apart immediately." The transmission broke, severing the tail, and the rotor blades struck the ground. The Federal Aviation Administration inspector noted that the helicopter never lifted off the ground during the accident flight.
Previous Occurrences
The pilot had experienced ground resonance on three previous flights. The first occurred during takeoff and the other two during landing. During those instances, the pilot was able to identify and successfully recover from the ground resonance. In this accident, the pilot was too late in recognizing the onset of ground resonance. No mechanical anomalies were found that would have precluded normal operation.