What happened
On March 14, 2009, a Robinson R22 Beta, registration N157SH, was involved in an accident in Douglas, Arizona. The pilot landed the helicopter on a semi-trailer for the purpose of paying a truck driver for a load of hay. After landing, the pilot exited the aircraft while the engine was still running, the control frictions were engaged, and the governor was off. While the pilot was engaged in the transaction with the driver, the helicopter fell off the trailer, resulting in substantial damage to the tail boom. There were no injuries resulting from the event.
The investigation
The investigation focused on the state of the aircraft at the time the pilot exited the cockpit. It was determined that the engine remained running and the governor was disengaged during the period the pilot was outside the aircraft.