Flight History
The aircraft was operating under Instrument Flight Rules (IFR) at an altitude of 12,000 feet when both vacuum pumps failed. Subsequently, the aircraft descended while making a right turn and disappeared from radar coverage.
Witness Observations
Witnesses on the ground observed the aircraft at low altitude above trees. They reported seeing the aircraft circle, execute a steep left turn, climb, and then descend until it contacted the ground.
The pilot, who was the sole occupant, was killed in the accident.
Probable Cause
The official findings list two occurrences:
Occurrence #1: Loss of control – in flight Phase of operation: cruise Findings: 1. Vacuum system – failure (total) 2. IFR procedure – improper (pilot in command) 3. Flight/nav instruments, attitude gyro – inoperative 4. Stall – inadvertent (pilot in command) 5. Spatial disorientation (pilot in command)
Occurrence #2: In flight collision with terrain/water Phase of operation: descent – uncontrolled