Accident Overview
A helicopter involved in a cattle roundup operation struck terrain while flying in a canyon. The aircraft had departed from cattle pens and was heading east-northeast toward a draw that led into the canyon.
Terrain and Environmental Conditions
The elevation at the cattle pens was approximately 5,000 feet, with an upslope exceeding 15 degrees leading into the canyon. The wind in the canyon was from the south-southwest at 10 knots, gusting to 15 knots, and the temperature was between 75 and 80 degrees Fahrenheit. The density altitude was calculated at 7,346 feet at the time of the accident.
Impact Details
The helicopter collided with the upslope of the canyon about 100 feet below the ridge at an elevation of 5,080 feet. Physical deformation of the main rotor blades was consistent with impact against tree branches along their leading edges.
Pilot and Aircraft Information
The pilot had accumulated 695.4 hours of flight time in the accident make and model of helicopter. Examination of the wreckage revealed no evidence of pre-impact flight control malfunction or failure of the airframe or any system. The helicopter was found to be within weight and balance limits at a calculated gross weight of 1,292 pounds. According to performance data, the maximum altitude to hover out of ground effect (OGE) at that weight was 5,200 feet, and the maximum altitude to hover in ground effect (IGE) was 9,200 feet.