Flight History
On the date of the accident, N7460N was operating as Mid-America Flight 401 on an IFR flight plan en route to Corpus Christi, Texas. The aircraft had been vectored around a heavy thunderstorm and was cleared direct to Waco, Texas. The pilot contacted Fort Worth Center and reported, "I lost my artificial horizon and my directional gyro." After controllers asked whether the aircraft had a compass and received an affirmative reply, the pilot was instructed to turn to a heading of 010. Shortly thereafter, the radar target was lost.
Pilot Background
Investigation revealed that the pilot had been employed by Mid-America for approximately three weeks as a night refueler. On the day of the accident, the pilot was reportedly given a 1.2-hour Part 135 check ride by the company's assistant chief pilot.
Investigation Findings
Examination of the wreckage showed that the vacuum pump drive was sheared, with the sheared ends polished, indicating that the driving end continued rotating after shaft separation. One vacuum-driven gyro exhibited no evidence of rotation at impact. The gyro from the electrically powered turn-and-bank indicator also showed no signs of rotation at impact.