What happened
At approximately 1400 Pacific daylight time, a Tweedsmuir Air Services Ltd. Cessna A185F (registration CF-BUO) crashed into a hillside in the vicinity of Mount Downton, British Columbia. The aircraft had departed Nimpo Lake with the pilot on board, intending to pick up a passenger from Kluskoil Lake before returning to Nimpo Lake. After the aircraft was reported overdue, a search was initiated, and investigators eventually located the wreckage at an elevation of 6,824 feet. The impact destroyed the aircraft, and both occupants sustained fatal injuries.
The investigation
Investigators examined the wreckage on a steep, eastern-facing slope. The damage to the wings, tail, and propeller suggested the aircraft struck the terrain at a slow forward speed, potentially following a stall, which caused it to flip nose-first. Evidence from a passenger's video recorder showed the aircraft approaching the site at an altitude insufficient to clear the upcoming terrain. The footage captured the aircraft rolling into a steep right bank before the recording ended.
Technical inspections of the aircraft revealed that the fuel selector was in the both-on position and the fuel shut-off valve was open. The engine had been displaced from its mounts, and the fuel tanks had ruptured. While the aircraft's maintenance records, engine, and flight controls appeared to be in good order, there was no record of a weight and balance calculation for the flight. The aircraft was estimated to be near its maximum allowable gross weight.
Regarding the pilot, the investigation confirmed he was a qualified commercial pilot with 830 total flying hours. While he had recently completed company training, there was no evidence of specific mountain flying training or experience. Toxicology and autopsy results showed no impairments. Meteorological data indicated that while the cloud ceiling was above the mountain tops, the area was experiencing light rain, mist, and a recent report of 40-knot winds from the southeast.
Findings
- The pilot was maneuvering the aircraft in close proximity to terrain.
- The aircraft struck the ground at a slow speed in a nose-down attitude, likely following a stall.
- A lack of mountain flying experience likely led to a misjudgment of terrain clearance.
- Strong southeast winds may have contributed to the accident.