What happened
On a scheduled flight from Paris-Foissy-Charles-de-Gaulle International Airport to Toronto, an Air France Airbus A340-313, registration F-GLZQ, encountered severe weather conditions while approaching Toronto/Lester B. Pearson International Airport. The flight crew had been monitoring reports of thunderstorms and heavy rain, and were aware of poor braking action reported by preceding aircraft on Runway 24L.
During the final approach, the pilot flying disconnected the autopilot and autothroltle at approximately 323 feet above ground level. At this time, the aircraft began to deviate above the glideslope, and the groundspeed increased as the wind shifted to include a tailwind component. The aircraft crossed the runway threshold roughly 40 feet above the glideslope.
As the aircraft entered a zone of heavy rain and experienced numerous lightning strikes, visual contact with the runway was significantly reduced. The aircraft touched down approximately 3800 feet down the 9000-foot runway. Despite the use of reverse thrust, the aircraft could not stop within the available distance and exited the far end of the runway at approximately 80 knots. The aircraft came to a stop in a ravine, where it caught fire. While all occupants successfully evacuated, the accident resulted in 2 crew members and 10 passengers sustaining serious injuries.
The investigation
The investigation focused on the human factors and decision-making processes, as all aircraft systems were found to be functioning correctly. Investigators examined the flight crew's approach preparations, noting that while the crew was aware of the weather, they had not calculated the specific landing distance required for the contaminated runway and tailwind conditions.
Analysis of the landing performance charts revealed that the predicted landing distance for the aircraft under these specific conditions exceeded the actual length of Runway 24L. The investigation also looked into the runway environment, specifically the area beyond the runway end, and the effectiveness of the emergency evacuation process.