What happened
On April 3, 2001, a Royal Cargo Boeing 737-200, registration C-GDCC, was conducting a scheduled cargo flight from Halifax to St. John's, Newfoundland. The flight crew, consisting of a training captain and a trainee captain, arrived at St. John's International Airport facing challenging weather conditions, including light snow, blowing snow, and low visibility.
During the approach to Runway 16, the crew relied on wind information from the Gander Area Control Centre that was significantly lower than the actual conditions. This discrepancy was caused by an iced-over anemometer at the airport providing inaccurate readings to the controller. Additionally, the crew applied an incorrect method for calculating approach speed, adding both a gust factor and a tailwind correction, which deviated from the aircraft's operations manual.
The aircraft touched down approximately 2,300 to 2,500 feet beyond the runway threshold at a speed of 164 KIAS, which was 27 knots above the intended reference speed. Despite deploying thrust reversers and brakes, the aircraft could not stop within the remaining runway length. The aircraft exited the departure end of the runway and came to rest in deep snow approximately 75 feet from the end. The two pilots were uninjured, but the aircraft sustained substantial damage, including engine damage and a detached left engine.
The investigation
The TSB examined the flight data, cockpit voice recordings, and the meteorological reporting chain. The investigation established that the crew failed to obtain the latest NOTAMs before departure, which would have informed them of the unserviceable ILS on Runway 11. The investigation also looked into the accuracy of the wind reports provided by Gander ACC and the mechanical failure of the St. John's anemometer. Furthermore, the investigators reviewed the crew's landing performance calculations, specifically their use of a rule of thumb to convert the Canadian runway friction index to a braking coefficient, and their application of tailwind corrections.
Findings
- The primary cause of the overrun was a combination of excessive landing speed, an extended touchdown point, and a low runway friction coefficient.
- The flight crew did not request or receive updated NOTAMs regarding the unserviceable ILS for Runway 11 prior to departure.
- Inaccurate wind data was transmitted to the crew because an anemometer at St. John's was malfunctioning due to ice accretion.
- The crew utilized an inappropriate method for calculating approach speeds by adding both gust and tailwind corrections, contrary to the approved operations manual.
- The crew's performance showed signs of reduced alertness, including difficulty completing checklists and failing to acknowledge significant wind discrepancies.