What happened
The pilot-in-command was operating an aircraft with the intention of crossing Merrill Pass. Weather conditions in the area were forecast to be marginal, and other pilots in the vicinity reported that the pass was marginal to closed for through traffic. Despite these warnings and forecasts, the pilot proceeded toward the mountain pass.
The wreckage was located in a box canyon situated one valley short of the intended pass. The turn required to enter this box canyon was identical to the maneuver necessary to proceed through the pass itself. The aircraft impacted a glacier at an elevation of approximately 4,000 feet. The impact orientation was perpendicular to the long axis of the box canyon. The glacier and surrounding mountains were covered with fresh snow at the time of the accident.
Findings
The primary factors contributing to this accident included marginal weather conditions and the decision to continue flight into deteriorating visibility. The pilot failed to recognize or act upon reports indicating that the pass was closed or impassable. The aircraft crashed on a glacier, suggesting a loss of spatial orientation or control in instrument meteorological conditions.
Safety message
Pilots must strictly adhere to weather forecasts and real-time reports from other aviators regarding mountain passes. If conditions are reported as marginal or closed, the pass should not be attempted. Continuing flight into known poor weather in mountainous terrain significantly increases the risk of controlled flight into terrain.