What happened
On 27 November 2008, a BAe Jetstream 3112, registration C-FNAY, was performing a scheduled commuter flight from Hay River to Fort Smith, Northwest Territories. After an initial missed approach to Runway 11, the crew transitioned to a procedure approach for Runway 29. As the aircraft approached the runway threshold, the crew identified the approach strobe lights and decided to proceed with the landing.
During the final stages of the approach, the crew reduced power to flight idle and selected 35° of flap. As the aircraft slowed toward its target speed, the stall warning horn activated. The aircraft entered an aerodynamic stall and struck the runway. The impact caused the left main landing gear to collapse, and the aircraft skidded approximately 1,778 feet along the runway. All five occupants—two crew members and three passengers—evacuated the aircraft without injury.
The investigation
The investigation focused on the aircraft's configuration changes and the environmental conditions during the approach. Investigators examined the cockpit voice recorder and reviewed the company's standard operating procedures (SOP). The investigation also looked into the aircraft's maintenance records and the presence of icing during the flight.
It was established that the aircraft had encountered light to moderate icing conditions during the approaches. While rime and clear ice were observed on the wings and propeller spinners, the crew did not activate the airframe de-imicng boots. Furthermore, the investigation noted that the company had not yet updated its SOPs to reflect a recent manufacturer notice regarding flap and speed management during instrument approaches.
Findings
- The aircraft entered an aerodynamic stall because of decreased performance caused by icing.
- The crew did not cycle the de-icing boots or increase the reference speed to compensate for the icing conditions.
- An abrupt change in configuration, involving a reduction to flight idle power and the selection of 35° flap, caused a rapid loss of airspeed.
- The decision to land once visual references were sighted left the crew with insufficient altitude and distance to safely reconfigure the aircraft.
- The company's failure to incorporate recent manufacturer safety notices into its SOPs increased the risk of unstabilized approaches.