What happened
On a flight from Pemberton Airport to Edmonton, a highly modified Cessna T207A, registered C-GGQR, entered a mountain pass route near Joffre Creek. The aircraft, which was configured with specialized equipment pods for air quality research, was performing a repositioning flight. During the climb, the aircraft encountered steeply rising terrain. As the pilot attempted to reverse course to avoid the approaching peaks, the aircraft entered a steep, descending left turn. The aircraft struck treetops and subsequently hit the sloping ground, where a post-crash fire consumed much of the airframe. The pilot was fatally injured.
The investigation
Investigators examined the wreckage and the environmental conditions at the site. The investigation established that the aircraft's engine was producing significant power at the time of impact, as evidenced by damage to the propeller blades. The aircraft was operating under a special flight permit and was carrying heavy modifications, including laser probe pods and electronic equipment. The investigation also looked into the weather, noting that the site was in a large shadow region, which can contribute to the formation of katabatic winds or downdraughts. Additionally, the investigation reviewed the pilot's training and the regulatory framework for modified aircraft operating under special permits.
Findings
- The pilot entered the valley at an altitude that did not allow for sufficient clearance of the terrain, given the aircraft's specific performance capabilities.
- While attempting to reverse course due to the rising terrain, the pilot likely experienced false horizon and relative scale illusions.
- The combination of the aircraft's high weight, increased drag from external equipment, high density altitude, and down-flowing winds made it impossible to clear the terrain during the maneuver.
- The lack of a detailed flight plan meant that the presence of specialized equipment was not reported, which could impact search and rescue operations.
- The aircraft was operating at an increased weight allowance that had not been formally incorporated into the official Transport Canada flight authority.