Introduction
A Cessna 172N, registered C-GGFT, departed Tulita, Northwest Territories, on 31 December 2001 for planned flights to Norman Wells, Fort Good Hope, and return to Tulita. The aircraft, carrying a pilot and three passengers, did not arrive at Norman Wells and was reported overdue at 1500 mountain standard time (MST). A search was initiated, and an emergency locator transmitter signal was detected around midnight on 31 December by an overflying C-130 Hercules. Due to weather, terrain, and short daylight hours, the wreckage was found on the afternoon of 2 January 2002, 30 nautical miles south of Fort Good Hope at the 1100-foot level of a 1400-foot mountain, on a rock face with about a 70-degree slope. All four occupants were deceased, and the aircraft was substantially damaged.
Flight History
The pilot checked weather and departed Tulita at approximately 1000 MST. Upon arrival at Norman Wells, the weather was below visual flight rules (VFR) conditions, and the pilot requested and was approved for a special VFR (SVFR) arrival. After landing at about 1020, the aircraft was refuelled. The pilot entered the Flight Service Station (FSS) for a weather briefing but left before it was complete to supervise refuelling. Meanwhile, another Cessna 172, C-GYYX, departed Norman Wells under SVFR for Fort Good Hope but returned after 15 nautical miles, reporting decreasing visibility and ceiling to treetop level and ice accumulation on the airframe and windshield. The pilot of C-GGFT received this PIREP as he was departing Norman Wells but decided to proceed. A passenger boarded at Norman Wells, and C-GGFT departed under SVFR for Fort Good Hope. En route, the pilot encountered marginal weather and attempted different routes. The aircraft arrived in Fort Good Hope after a flight about 30 minutes longer than planned. Upon landing, the aircraft was observed to have ¾ to 1 inch of ice on the leading edges of wings and tail surfaces, and about ¼ inch of ice on the windshield.
At Fort Good Hope, the pilot telephoned his company base and filed a flight itinerary for the return trip, noting marginal weather and his plan to follow the river. He was aware another pilot had departed VFR and returned due to adverse weather. He discussed aborting or delaying, but after removing ice from the aircraft, three passengers boarded. As he taxied, he received a call from a DC4 freighter pilot advising IFR conditions in Norman Wells and icing en route. The pilot acknowledged and departed Fort Good Hope at approximately 1315.
Wreckage and Recovery
The accident site is 30 nautical miles south of Fort Good Hope at the 1100-foot level of a 1400-foot mountain, on a rock face with about a 70-degree slope. Examination of the wreckage showed the aircraft struck the surface in straight and level flight, remained intact as it fell about 50 feet down the slope, and became entangled in a clump of trees. The engine was producing power at impact, and flaps appeared retracted. A layer of rime ice was evident on the wing struts. The GPS indicator was not recovered; the ADF was tuned to Tulita with the indicator pointing to the rear. Autopsy results revealed that the right front seat passenger was fatally injured by the impact, and the pilot and rear seat passengers survived the impact with non-life-threatening injuries but succumbed to hypothermia.
Pilot Information
The pilot was certified and qualified, holding a current instrument rating. He had 650 total flying hours, with about 460 hours on type. Since June 2001, he had flown approximately 370 hours, including 11 flights to Fort Good Hope. The aircraft was certified and equipped per regulations, with no indication of airframe failure or system malfunction. The aircraft was not certified for flight in known icing conditions. Weight and centre of gravity were within limits.
Probable Cause
The investigation concluded: "The pilot flew into the side of a mountain for reasons related to ice accumulation and/or reduced visibility in snow showers or cloud." The aircraft had been flown into known weather and icing conditions for which it was neither equipped nor certified.