Air transportation safety investigation A18A0085

The occurrence

The Sky Lease Cargo Boeing 747-412F aircraft (U.S. registration N908AR, serial number 28026) was conducting flight 4854 (KYE4854) from Chicago/O’Hare International Airport, Illinois, U.S., to Halifax/Stanfield International Airport, Nova Scotia, with 3 crew members, 1 passenger, and no cargo on board.

The crew conducted the Runway 14 instrument landing system approach. When the aircraft was 1 minute and 21 seconds from the threshold, the crew realized that there was a tailwind; however, they did not recalculate the performance data to confirm that the landing distance available was still acceptable, likely because of the limited amount of time available before landing. The unexpected tailwind resulted in a greater landing distance required , but this distance did not exceed the length of the runway.

The aircraft touched down firmly at approximately 0506 Atlantic Standard Time, during the hours of darkness. After the firm touchdown, for undetermined reasons, the engine No. 1 thrust lever was moved forward of the idle position, causing the speed brakes to retract and the autobrake system to disengage, increasing the distance required to bring the aircraft to a stop. In addition, the right crab angle (4.5°) on initial touchdown, combined with the crosswind component and asymmetric reverser selection, caused the aircraft to deviate to the right of the runway centreline.

During the landing roll, the pilot monitoring’s attention was focused on the lateral drift and, as a result, the required callouts regarding the position of the deceleration devices were not made.

Although manual brake application began 8 seconds after touchdown, maximum braking effort did not occur until 15 seconds later, when the aircraft was 800 feet from the end of the runway. At this position, it was not possible for the aircraft to stop on the runway and, 5 seconds later, the aircraft departed the end of the runway at a speed of 77 knots and came to a stop 270 m (885 feet) past the end.

The aircraft struck the approach light stanchions and the localizer antenna array. The No. 2 engine detached from its pylon during the impact sequence and came to rest under the left horizontal stabilizer, causing a fire in the tail section following the impact. The emergency locator transmitter activated. Aircraft rescue and firefighting personnel responded. All 3 crew members received minor injuries and were taken to the hospital. The passenger was not injured.

During the overrun, the aircraft crossed a significant drop of 2.8 m (9 feet) approximately 166 m (544 feet) past the end of the runway and was damaged beyond repair. While this uneven terrain was beyond the 150 m (492 feet) runway end safety area proposed by Transport Canada, it was within the recommended International Civil Aviation Organization runway end safety area of 300 m (984 feet). In 2007, the Board recommended that 

In addition, runway overruns is one of the issues on the TSB’s Watchlist 2020. The TSB Watchlist identifies the key safety issues that need to be addressed to make Canada’s transportation system even safer.

The investigation included a thorough fatigue analysis, which identified the presence of 2 fatigue risk factors that would have degraded the crew’s performance during the approach and landing: the timing of the flight and insufficient restorative sleep in the 24-hour period leading up to the occurrence. Fatigue management is also one of the safety issues on the TSB’s Watchlist 2020.

Media materials

News release

Deployment notice

Video