What happened
On 25 October 2010, a Kenn Borek Air Ltd. Beechcraft 100, registration C-FAFD, was conducting an instrument flight rules (IFR) flight from Edmonton City Centre Airport to Kirby Lake, Alberta. During the approach to Runway 08, the aircraft struck the ground approximately 174 feet short of the runway threshold. The impact caused the aircraft to bounce and come to rest off the edge of the runway, resulting in a small electrical fire in the cockpit.
The flight was carrying two crew members and eight passengers. The accident resulted in one fatality, four serious injuries, and five minor injuries. The aircraft sustained substantial damage.
As the aircraft approached the final approach waypoint, the crew began looking outside the cockpit to visually identify the runway. During this period, the pilot flying disconnected the autopilot to manually intercept the track. As the crew focused on visual acquisition, the aircraft's airspeed decreased significantly. The left wing dropped, and the aircraft entered an aerodynamic stall. Despite the crew applying maximum power, the low altitude prevented a successful recovery before ground impact.
The investigation
The investigation examined the crew's performance, cockpit discipline, and the aircraft's mechanical state. Investigators found that the crew was engaged in non-essential conversation during the approach, which contributed to a lack of heightened attention. Furthermore, the crew failed to make required altitude callouts and descended below the minimum descent altitude (MDA) without proper verification.
Technical analysis revealed that the pilot flying was managing a higher workload because the GPS track information was only displayed on the left-side horizontal situation indicator, necessitating an expanded instrument scan. Additionally, the investigation noted that the aircraft was operating with an inaccurate weight due to the use of non-current weight and balance reports. While the de-icing systems were functional, the investigation could not determine why the aircraft's stall warning horn failed to activate prior to the stall.
Findings
- The crew's focus on visually locating the runway diverted their attention from monitoring the aircraft's flight profile.
- The aircraft entered an aerodynamic stall due to a reduction in airspeed during the descent.
- The failure of the stall warning system to activate deprived the crew of a critical warning.
- Deviating from the established approach profile and failing to apply proper transition altitudes increased the risk of terrain encounter.
- Inaccurate weight and balance calculations resulted in the aircraft operating at an unanticipated performance regime.