What happened
On 31 July 2010, a Conair Group Inc. Convair 580, registered as C–FKFY, was engaged in aerial firefighting near Lytton, British Columbia. Operating as Tanker 448, the crew was executing a planned bombing run to suppress a wildfire in a ravine near the Fraser River canyon. The mission involved a specific triangular flight pattern designed to navigate the local terrain.
During the maneuver, the aircraft struck trees at the edge of a ravine. At the moment of impact, an unplanned partial release of retardant occurred. Following the collision, the aircraft entered a left-hand spin and struck the ground. The subsequent impact caused an explosion and fire that destroyed much of the wreckage. The two crew members on board were killed in the accident. An emergency locator transmitter was not recovered from the site.
The investigation
Investigators examined the flight history and mechanical state of the aircraft. The mission utilized a "bird dog" aircraft to direct the tanker's path. The investigation confirmed that both engines were producing maximum power and the propellers were functioning normally. There were no evidence of in-flight mechanical failures or airframe malfunctions prior to the tree strikes.
Technical checks of the landing lights and flap settings indicated that the crew had completed the necessary bombing checklists. The partial retardant drop confirmed that the hydraulic and delivery systems were operational. Investigators also noted that the captain was capable of operating the drop button, as the mechanism is located on the left seat, suggesting no sudden incapacitation of the pilot.
Findings
- The aircraft had descended significantly during its approach to the ravine, creating a low energy condition characterized by a slow climb and rising terrain.
- A visual illusion likely prevented the crew from accurately perceiving their altitude and proximity to the rising terrain.
- The lack of a clear horizon, combined with evening shadows and smoke, contributed to the crew's inability to recognize the imminent danger.
- The location of the angle-of-attack indicator made it difficult for the pilot not flying to monitor critical flight parameters.
- The emergency drop system's location required a high level of concentration to operate, which may have diverted attention during the critical seconds of the encounter.