What happened
During a scheduled flight from Arvidsjaur to Gällivare airport, a Fokker F28 Mark 0100, registration YR-FZA, experienced a runway excursion. The flight was operated by Carpatair on behalf of the Swedish carrier Nextjet. The approach to runway 30 was conducted at night under challenging weather conditions involving rain and snow.
As the aircraft crossed the runway threshold at approximately 50 feet, it maintained a speed of 134 knots. The aircraft subsequently experienced a hard landing within the touchdown zone. Due to the high speed and the impact, the aircraft bounced and underwent a lateral displacement in yaw. Following the touchdown, the crew utilized full flaps and extended the speed brake, and the wing's lift dumpers deployed. While maximum reverse thrust was engaged, the engine reverse RPM only reached between 65% and 75%, significantly below the 95.5% limit. The aircraft eventually overran the end of the runway, coming to a stop on the runway strip. There were no injuries reported, and the damage to the aircraft was minimal.
The investigation
The investigation focused on the deceleration capabilities of the aircraft and the environmental conditions at the time of the incident. Investigators analyzed friction coefficients, which were recorded between 0.34 and 0.36. The investigation also examined the timing of the crew's actions, specifically noting that the increase in reverse thrust RPM occurred approximately 20 seconds after touchdown, at a speed of roughly 50 knots. Additionally, the investigation looked into the mechanical and operational aspects of the braking and thrust reversal application.
Findings
- The primary cause of the incident was the gradual deterioration of landing conditions that was not recognized by the crew in a timely manner.
- The aircraft's airspeed remained constant from 50 feet above the threshold through to the moment of touchdown.
- The reported runway friction coefficients were likely unreliable.
- The initial yaw disturbance following the bounce likely prevented the full application of the wheel brakes.
- There was a significant delay in the deployment of reverse thrust, with the RPM increasing only 20 seconds after the aircraft touched the ground.