What happened
During a low-level flight operation over mountainous terrain, an aircraft carrying a pilot and one passenger was involved in a fatal collision with the ground. At the time of the accident, surface winds were recorded as originating from the south at speeds of at least 20 knots.
As the pilot approached a mountain peak from a southerly direction, he increased power to reach an altitude of approximately 150 feet above the terrain to ensure clearance. While the pilot was in the process of performing a 180-degree turn, the aircraft entered the lee side of the mountain, where it encountered significant downdraft conditions. The aircraft subsequently struck the upsloping terrain. The accident resulted in two fatalities.
Findings
Investigation into the flight sequence indicates that the aircraft encountered atmospheric disturbances caused by the wind interacting with the mountain topography. The primary factor in the accident was the pilot's failure to immediately compensate for the downdrafts encountered on the leeward side of the peak during the turning maneuver.