Accident Overview
A pilot was flying low and herding antelope when his helicopter impacted the terrain and was destroyed. The pilot remained conscious after the accident but died approximately three hours later.
Pilot's Statement
Before dying, the pilot reported that the engine had lost power. However, investigation revealed no pre-impact part failure or malfunction of the aircraft or engine that would have led to a power loss.
Wreckage Examination
Examination of the wreckage showed the helicopter had impacted in a left bank, nose-low attitude. All three main rotor blades exhibited evidence of high flapping angles at impact.
Toxicology Results
Toxicology tests of the pilot's blood, liver, and kidney detected nordiazepam at levels of 0.104 mg/L (blood), 0.846 mg/L (liver), and 0.427 mg/L (kidney). The toxicologist reported the therapeutic range for nordiazepam in blood as 0.02 to 0.18 mg/L. Nordiazepam is a sedative and central nervous system depressant that is not approved for flying.