What happened
On a charter flight departing from Tasu, British Columbia, a float-equipped DHC-3 Otter crashed into a valley wall at an elevation of 1,700 feet. The flight, which included the pilot and two passengers, was traveling under visual flight rules toward Allifly Bay. After the aircraft failed to arrive at its destination, a search was launched, leading to the discovery of the wreckage the following day, approximately 18 nautical miles south of Alliford Bay.
There were three fatalities in the accident, as all occupants perished. The aircraft was destroyed upon impact with the terrain.
The investigation
Investigators examined the aircraft's mechanical condition and the environmental circumstances surrounding the flight. The DHC-3 Otter was found to be properly maintained, certified, and equipped, with the weight and center of gravity within legal limits. An examination of the Pratt & Whitney PT6 A-135 turbine engine confirmed it was fully operational and capable of producing maximum power at the time of the crash. No pre-impact structural or mechanical failures were identified, and the pilot was fully qualified for the operation.
Regarding the flight path, the investigation noted that the pilot's intended route involved crossing low terrain and turning east through a valley toward Sewell Inlet. However, the aircraft struck the side of a different valley that leads north into a box canyon. Evidence from the wreckage indicated the aircraft was in a controlled, wings-level flight on a heading of approximately 210 degrees magnetic at the moment of impact, traveling at roughly 80 miles per hour.
Findings
- The pilot likely committed a navigational error due to fog and light drizzle, which caused the aircraft to enter the northern valley instead of turning east toward the intended destination.
- The pilot may have reversed the aircraft's course either because the error was realized or because of deteriorating weather, but this decision was likely delayed until weather conditions became unavoidable.
- Restricted forward visibility, caused by entering cloud cover, likely prevented the pilot from seeing the rising terrain in time to perform evasive maneuvers.