Accident Details
The accident occurred during a night VFR traffic pattern at a non-towered airport. The pilot of a turboprop aircraft was performing a full-stop landing. He entered the traffic pattern on an extended downwind leg at 6,800 feet (1,000 feet AGL) with a ground speed of 205 knots, as indicated by radar data. Over the next 3 nautical miles on downwind, the pilot slowed to 171 knots ground speed, lost approximately 500 feet of altitude, and reduced his parallel distance from the runway from 4,775 feet to 2,775 feet.
Flight Path
Witnesses reported that the pilot's radio transmissions on CTAF appeared normal. Two witnesses observed a bright blue flash, after which contact with the aircraft was lost. Radar data showed that during the turn from base to final, the pilot was in a maximum descent of 1,800 to 1,900 feet per minute, with an airspeed on final of 145 to 150 knots. The maximum bank angle during this turn was calculated to exceed 70 degrees.
Rescue and Discovery
The dark night hindered ground rescue personnel from locating the downed aircraft. A police helicopter found the airplane approximately two hours after the accident. Rescue personnel discovered a broken and downed static wire from a system of three sets of power transmission wires. The separated static wire was located 8,266.5 feet from the runway threshold and was approximately 30 feet higher than the threshold.
Post-Accident Examination
Post-accident examinations of the aircraft and its engine revealed no anomalies that would have precluded normal operations prior to impact.
Probable Cause
The official probable cause was the pilot's unstabilized approach and his failure to maintain obstacle clearance. Contributing factors were the dark night light condition and the static wires.