History of the Flight
The aircraft, a Piper PA-31-350 Chieftain, was conducting a scheduled visual flight rules (VFR) flight from Terrace to Iskut, Dease Lake, Bronson Creek, and back to Terrace, British Columbia. It departed Terrace at about 1005 Pacific standard time (PST) and arrived at Iskut about 1145. After brief stops, it departed Bronson Creek for Terrace at about 1350 with the pilot and three passengers on board. About ten minutes later, the pilot communicated by radio with another pilot near the Iskut River valley, approximately 20 miles east of Bronson Creek. This was the last reported contact; no problems were reported.
After the aircraft was reported missing, an air and ground search was conducted but failed to locate it. No emergency locator transmitter (ELT) signal was detected. The wreckage was discovered by chance on 05 August 1994, nearly four years after the accident.
Injuries and Damage
The pilot and three passengers did not survive the impact. The aircraft broke up on impact; a post-crash fire consumed the upper fuselage. All other parts were recovered. Damage to propeller blades indicated the engines were producing power at impact. Tree damage and wreckage pattern showed the aircraft hit trees in straight and level flight on a heading of about 360 degrees magnetic. The accident site was at about 3,500 feet above sea level on steep, sub-alpine terrain.
Pilot Information
The pilot, aged 67, held an Airline Transport Pilot Licence and had 13,000 total flying hours, including 1,000 hours on type. He was qualified, reported healthy and well-rested, and had an instrument rating since 1974 with about 700 instrument hours. However, he had not flown in instrument meteorological conditions in the preceding two years and had failed to renew his instrument rating in June 1990 due to inability to maintain control with reference to instruments.
Aircraft Information
The aircraft (Piper PA-31-350, serial number 31-7852004) was manufactured in 1978 with 5,520 total airframe hours. It was equipped with two Lycoming LTIO-540-J2BD engines and Hartzell propellers. Maintenance records showed no mechanical problems; instruments and avionics were serviceable, including the autopilot and ELT. Weight and centre of gravity were within limits, and fuel was sufficient for the planned flight.
Meteorological Information
Forecast weather for the area included scattered to broken clouds, visibility reduced by rain and snow showers, and moderate turbulence. At Terrace (elevation 713 feet asl), the reported weather included scattered cloud at 500 and 1,200 feet, overcast at 8,000 feet, visibility six miles in light rain and smoke. An aftercast for the accident site indicated heavy convective clouds based at 3,000 feet asl with moderate turbulence, patchy stratus, freezing level at 3,000 feet, and heavy snow above with rain below. Conditions were not suitable for VFR flight in mountainous terrain.
Analysis
The evidence indicated the aircraft was in straight and level controlled flight with both engines producing cruise power when it struck trees. The pilot was likely attempting to maintain visual flight below cloud and in poor visibility. The aircraft was found heading north despite its southbound route to Terrace, possibly due to manoeuvring to avoid weather or becoming lost. The ELT was damaged at impact and did not transmit.
Probable Cause
The pilot likely attempted to continue the visual flight into an area of instrument meteorological conditions.