What happened
The flight originated from Hornell, New York, bound for Wellsville. Before departing Hornell, the pilot reported that the vacuum annunciator light was illuminated and the suction gauge read zero during a run-up. Ground personnel explicitly warned that the artificial horizon, directional gyro, and autopilot would be inoperative due to this failure and advised staying clear of clouds.
Despite these warnings, the aircraft departed Wellsville at approximately 0925 into weather conditions estimated at 900 feet overcast with visibility between 1.5 to 2 miles. Approximately ten minutes later, the Cessna 177RG crashed and burned after impacting trees on rising terrain, roughly 7 miles east-southeast of the airport. The impact occurred on a heading of 240 degrees.
Witnesses near the crash site reported hearing an aircraft traveling generally from west to east that sounded loud and low. One witness stated they could not see the aircraft due to dense fog. The pilot was not instrument rated, having received only dual instrument training but very little partial panel experience.
The investigation
A post-accident examination of the vacuum pump revealed that the drive shaft had been sheared, confirming the loss of suction indicated prior to departure.
Findings
The pilot continued flight into marginal weather conditions despite being aware of a critical instrument failure. The lack of adequate partial panel training likely contributed to the inability to maintain control without visual references. The 3 fatal injuries sustained by those on board were consistent with the high-energy impact.
Safety message
Pilots must respect aircraft limitations and ground crew advice regarding inoperative instruments. Flying a non-instrument rated aircraft into clouds with failed attitude indicators is extremely dangerous.