What happened
The aircraft was engaged in a night instrument training flight when it ultimately crashed into a wheat field. Approximately forty minutes after takeoff, the pilot declared a failure of the vacuum system. Despite this emergency declaration, the pilot declined air traffic control assistance for a no-gyro approach to Columbus. Two minutes after the radio call indicating the loss of radar contact, radar data revealed erratic changes in both heading and airspeed during the final minute of the flight.
The investigation
Post-acc examination of the wreckage revealed that each instrument contained a suction cup. No evidence of failure or malfunction was found regarding the primary vacuum system. The aircraft had been modified to include a standby vacuum system for emergency use following primary system failure. Although only pieces of this secondary system were recovered due to the destruction of the aircraft, available evidence showed no signs of malfunction or failure. Suction cups like those found are typically used by instructors to cover instruments during partial panel training.
Findings
The presence of suction cups on the instruments suggests the pilot was conducting partial panel training. The erratic flight parameters observed shortly before impact indicate a loss of situational awareness or control proficiency while managing simulated instrument failure without external radar guidance.