History of Flight
On June 29, 2018, about 2010 central daylight time, a Robinson R22B helicopter, registration N787SH, was destroyed when it crashed near Sterling, Texas. The pilot was fatally injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 91 work use flight. The purpose of the flight was to inspect a nearby stock water tank and an inoperative water pump. After completing the inspection, the pilot was returning to land on the helicopter's transport trailer when the accident occurred.
A witness located at the home base reported that she saw the helicopter approach to land on the trailer, but the pilot aborted the landing. The helicopter backed away from the trailer and climbed. As it climbed to about 20 to 25 ft above the ground, it began a violent spin, completing four or five rotations. The witness then heard a loud noise similar to an engine backfire, after which the helicopter fell to the ground. She could not recall whether the engine was producing power after the backfire. She believed the spin was counterclockwise but was not certain. Because of buildings, she did not see the impact. When she reached the helicopter, the engine was not running.
Aircraft Information
The helicopter was configured with a single set of flight controls (pedals, collective, and cyclic) at the right seat. The left seat pilot controls were not installed, and the cover plate for the removed left pedal assembly was also not installed. The operator stated that the helicopter was routinely used in cattle roundup and predator mitigation operations. Earlier that day, the helicopter had flown a previous flight of about 3.7 hours, and the pilot who conducted that flight reported no anomalies.
Meteorological Information
A company pilot reported that the wind was about 10 to 12 knots from the south at the time of the accident.
Wreckage and Impact Information
The accident site was about 200 ft from the intended landing site on the transport trailer. The helicopter impacted level terrain and came to rest on its right side. There was no evidence of contact with obstructions during the approach. The fuselage sustained impact damage to its lower right side. Both pilot and passenger doors were not installed. Three ammunition cans containing tools and several loose shotgun shells, both discharged and undischarged, were present within the wreckage area. Some shotgun shells were recovered from the left floor area, the belly area, and the debris field. One shotgun shell had a dent in its plastic shell.
Examination of the airframe and engine revealed no pre-impact mechanical anomalies. Flight control continuity was confirmed from the cockpit to the flight control surfaces.
The ammunition boxes were placed on the left side cockpit floor to observe their geometry relative to the removed left pedal assembly. The edge of the most-forward box covered the top of the left side pedal receiver when the right pedal was positioned aft of neutral. Due to impact damage, the positions of the ammunition boxes and the dented shotgun shell during the flight could not be determined.
Detailed airframe and engine examination findings are included in the public docket for this accident.
Medical and Pathological Information
An autopsy performed by South Plains Forensic Pathology, Lubbock, Texas, determined the pilot's cause of death to be multiple blunt force injuries. The FAA's Forensic Sciences Laboratory conducted toxicology testing on the pilot's tissue samples, which were negative for drugs and ethanol. Small amounts of over-the-counter medicine for hay fever and allergies were detected.