What happened
At approximately 00:30 Atlantic standard time, an Air Canada Regional Airlines Fokker F-2FR MK 1000, registration C-FCRK, landed at Saint John Airport following a scheduled night passenger flight from Toronto. While the aircraft initially touched down on the centerline of Runway 05, the nosewheel contact triggered an uncontrollable leftward drift. The aircraft veered off the runway edge, traveling approximately 900 feet alongside the runway before the crew regained partial control and brought the aircraft to a stop. There were no injuries among the 51 passengers and 4 crew members on board.
The investigation
The investigation focused on the runway surface conditions and the accuracy of the friction reports provided to the crew. Prior to the landing, the flight crew had received a Canadian Runway Friction Index (CRFI) report indicating a value of 0.52, which suggests good friction. However, investigators found that while the runway appeared snow-covered, a layer of slush had formed under the snow. This slush was not detected during the initial CRFI measurement, which had been taken roughly 20 minutes before arrival.
Furthermore, the investigation noted a significant discrepancy between the friction readings of the two airport runways. While Runway 05 was reported at 0.52, the non-landing runway (Runway 14/32) had a much lower reading of 0.23. This lower value indicated that melting was actively occurring on the airfield, a fact that was not communicated to the crew. The crew had also declined an offer for a centerline runway sweep, believing the reported conditions were sufficient for a safe landing.
Findings
- The primary cause of the excursion was poor runway friction characteristics caused by slush contamination, which prevented the crew from maintaining the aircraft's ground track.
- The reported CRFI value for Runway 05 was no longer accurate at the time of landing due to changing surface conditions.
- Ground personnel failed to recognize the significance of the differing friction values between the two runways, leading to a failure to re-assess the validity of the primary runway's report.
- There is currently no standard method for pilots to estimate the impact of slush on braking and steering performance using existing CRFI charts.