Accident Description
Radar data showed that the pilot flew the airplane from the departure airport toward the accident site. The last recorded radar target was at 610 feet above ground level (agl) over rising mountainous terrain. The floor of radar coverage in the area was about 200 feet agl. The accident site was located at an elevation of about 2,293 feet mean sea level (msl) on the slope of a bowl-shaped box canyon approximately 25 nautical miles from the departure airport.
The canyon and surrounding hills were steeply sloped, averaging between 60 to 80 degrees. The tops of the canyon terrain were about 700 feet higher than the accident site elevation and 1,000 feet laterally in front of the wreckage. An analysis of the airplane's climb performance capability found that a lateral distance of 2 miles would be required to climb 700 feet.
Impact Evidence
Ground scar analysis, impact signatures, and wreckage fragmentation patterns disclosed that the airplane impacted in a descending steep vertical nose-down attitude traveling downslope. The impact geometry was consistent with the airplane encountering an accelerated stall while attempting a course reversal in the canyon.
The width of the canyon immediately surrounding the wreckage measured about 1,250 feet. With a turn radius of 637.5 feet and airspeed of 99 knots (maneuvering speed), the bank angle required for the airplane to complete a 180-degree turn was a minimum of 55 degrees. According to stall speed versus angle of bank data, the stall speed would be 55 knots at 55 degrees of bank.
Examination Findings
No evidence of mechanical malfunction or failure was found during a post-accident examination of the airplane and engine. The pilot had accumulated 75 hours total flight experience, of which about 2 hours was in the same make and model as the accident airplane and acquired in the location of the departure airport.