Accident Overview
On October 28, 2016, at 1000 central daylight time, a Robinson Helicopter R22 Beta, registration N522KC, impacted terrain during a forced landing after a partial loss of engine power near Asherton, Texas. The helicopter was registered to Rotor Spec Aviation LLC and operated by the pilot under Title 14 Code of Federal Regulations Part 91 as an aerial wildlife survey flight. Day visual meteorological conditions prevailed at the time of the accident. The local flight originated from Asherton, Texas at an unknown time. The pilot was uninjured, and the helicopter sustained substantial damage.
Events
According to a Federal Aviation Administration inspector, the helicopter experienced a loss in rotor rpm while maneuvering at low level during a wildlife survey. The pilot then performed a forced landing to a field. A National Transportation Safety Board (NTSB) Pilot/Operator Aircraft Accident/Incident Report was not received from the pilot.
Examination Findings
Post-accident examination of the helicopter revealed a failure of one of the engine magnetos. The wreckage had been moved and sold by the operator without the knowledge of the Federal Aviation Administration inspector and the NTSB. The NTSB Investigator-in-Charge located the engine at an engine maintenance facility whose representative stated that he examined the engine magnetos. One of the magnetos, Bendix model number S4LSC-200, part number 10-600614-1, serial number J229358E, had an internal timing, efficiency gap (E-gap) failure. He said the magneto distributor gear was loose, and the distributor gear bushing was "flapping" around.
Additional Information
The accident occurred during a wildlife survey flight conducted under Part 91. No other aircraft or persons were involved. The operator sold the wreckage without notification to investigating authorities.