What happened
On the night of the incident, a Sky Lease Cargo Boeing 747-412F, registered N908AR, was operating flight 485 and approaching Runway 14 at Halifax/Stanfield International Airport from Chicago/O’Hare International Airport. The aircraft was carrying three crew members and one passenger, with no cargo on board. During the final stages of the instrument landing system approach, the crew identified a tailwind but failed to update their performance calculations to verify if the available runway length remained sufficient for the landing.
At approximately 0506 Atlantic Standard Time, the aircraft made a firm touchdown. Following the impact, the number 1 engine thrust lever was moved forward of the idle position, which triggered the retraction of the speed brakes and the disengagement of the autobrake system. This action, paired with an existing crosswind and a 4.5-degree crab angle, caused the aircraft to drift right of the runway centerline. During this period, the pilot monitoring was preoccupied with correcting the lateral drift, leading to a failure to communicate the status of deceleration devices.
Although braking was initiated 8 seconds after touchdown, full braking pressure was not applied until the aircraft was 800 feet from the runway end. Consequently, the aircraft exited the runway at 77 knots, traveling 270 meters past the threshold. During the excursion, the aircraft struck approach light stanchions and a localizer antenna array. The impact caused the number 2 engine to detach from its pylon and a fire to ignite in the tail section. The aircraft subsequently crossed a 2.8-meter drop and sustained damage beyond repair. There were 3 minor injuries reported among the crew, while the passenger remained unhurt.
Findings
- The crew did not recalculate landing performance data after discovering an unexpected tailwind.
- The movement of the number 1 engine thrust lever forward of idle caused the speed brakes to retract and the autobrakes to disengage.
- Pilot monitoring attention was diverted by the lateral drift, resulting in missed operational callouts.
- Delayed application of maximum braking effort contributed to the inability to stop within the runway limits.