Primary finding
Probable cause
The pilot-in-command's failure to maintain airspeed which resulted in an inadvertent stall at an altitude inadequate to affect a recovery. Factors which contributed to the accident were: the overweight airplane, and the snow covered mountainous terrain.
Investigator assessment
Analysis narrative
The purpose of flight was to count moose. The pilot had reported to another survey pilot, who was working in an area nearby and just over the ridge, that his assigned area had some fog in the upper elevations, but that it was workable. The pilot subsequently advised that the standard search had been completed, and that he was commencing the intensive search pattern. There was no further contact with the flight. During the intensive search, which takes 20-30 min to complete, a series of slightly overlapping circles or ovals are flown at 200-300 ft agl, at 60 to 70 mph, with one notch (15 deg) of flaps. The airplane impacted snow covered tundra nose first at an angle of approx 40 deg. At the time of the accident, the airplane was approx 300 lbs over max certificated gross weight.
Source record
Factual narrative
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