What happened
On a medical evacuation mission traveling from Pinehouse Lake to La Ronge Airport, Saskatchewan, a Beechcraft A100 King Air, registration C-GAPK, encountered accumulating ice on the wing leading edges during its descent. As the aircraft approached the runway on final approach, approximately 6 miles from the destination, the crew activated the wing de-ice boots to mitigate the buildup. Despite this action, a significant amount of ice remained on the wing surfaces.
During the landing flare at an airspeed of roughly 100 knots, the aircraft suffered an ice-induced stall at an altitude of approximately 20 feet. This resulted in a hard landing on the runway. The force of the impact caused the right wing and nacelle to buckle forward and downward. As the aircraft continued to taxi away from the runway, the right propeller made contact with the runway surface.
Findings
- The de-ice boots failed to sufficiently remove all residual ice from the wing leading edges.
- The presence of remaining ice led to an aerodynamic stall during the critical landing flare phase.