Accident Details
The aircraft was on an emergency medical services (EMS/med-evac) flight with a pilot and flight nurse aboard, transporting a maternity patient from Flagstaff to Phoenix. During a night arrival, the pilot began a VOR-A approach in instrument meteorological conditions (IMC). He then reported a problem with his avionics and elected to make a missed approach. During the missed approach, he stated that he had 'lost' an inverter and later reported the gyros were inoperative. Radar vectors were being provided when he said, 'We have big trouble here.' Shortly thereafter, radar and radio contact were lost, and the aircraft crashed approximately 7 miles southeast of the airport.
On impact, the aircraft made a deep crater and was demolished. No preimpact engine or airframe failure was found.
Investigation Findings
Investigation revealed that the number 2 (copilot's) attitude indicator was inoperative on the previous flight. A discrepancy report was taken to the avionics department, but the required entry was not made in the aircraft Form-4. The pilot took off before corrective action was taken.
The operations manual required 1,000 hours of multi-engine time as pilot-in-command and training by designated CFIs. The pilot had approximately 837 hours of multi-engine time, received 9 training flights in N6858S with non-designated instructors, and completed a Part 135 flight check on February 17, 1988.