What happened
At 00:53 Newfoundland daylight time, an Air Canada Airbus A320, registration C-FKCO, was conducting a scheduled flight from Toronto to St. John's. While performing a night localizer approach to runway 29, the aircraft encountered significant wind fluctuations. Due to ongoing construction, the runway threshold had been relocated, and the aircraft touched down approximately 250 feet before the new threshold, striking sawhorse-type construction barriers. The impact caused damage to one brake temperature sensor and two brake lines. There were no injuries to the occupants.
The investigation
The investigation examined the runway environment, weather conditions, and flight data. At the time of the incident, the threshold for runway 29 was displaced by 1767 feet. While the displaced threshold was marked with lights and cones, the high-intensity approach lights were unserviceable. Flight data recorder analysis showed that the pilot transitioned from autopilot to manual flight during the descent. As the aircraft approached the ground, it encountered strong vertical and longitudinal gusts.
Engine simulations revealed that while the pilot applied full nose-up side-stick input to counter a steepening descent, the aircraft's "Alpha Prot" protection system limited the elevator deflection to prevent a stall. This limitation, combined with a sudden loss of headwind near the ground, prevented the crew from sufficiently arresting the descent rate. Furthermore, the investigation noted that the runway lacked a visual approach slope indicator system (VASIS), which is recommended for such conditions.
Findings
- The approach environment was prone to the "black-hole illusion," where a lack of visual cues leads to depth perception errors.
- The aircraft was flying on a flightpath significantly lower than the nominal three-degree slope.
- Strong gusting winds caused a sudden loss of headwind and a corresponding increase in the rate of descent near the ground.
- The crew's ability to recognize the unsafe flightpath was hindered by the absence of external visual cues and the unserviceable approach lighting.
- The aircraft's automated protection systems limited the effectiveness of the pilot's manual corrective inputs during the final stages of the approach.