Air transportation safety investigation A18A0085
The TSB has completed this investigation. The report was published on 29 June 2021.
Sky Lease Cargo
Boeing 747-412F, N908AR
Halifax/Stanfield International Airport, Nova Scotia
View final report
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
the Department of Transport require all Code 4 runways to have a 300 m runway end safety area (RESA) or a means of stopping aircraft that provides an equivalent area of safety.
TSB Recommendation A07-06
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.
2018 Halifax runway overrun highlights TSB Watchlist issues
Read the news release
TSB deploys a team of investigators to a runway overrun at the Halifax Stanfield International Airport, Nova Scotia
The Transportation Safety Board of Canada (TSB) is deploying a team of investigators to a runway overrun at the Halifax Stanfield International Airport, Nova Scotia. The TSB will gather information and assess the occurrence.
Runway overruns and runway incursions on TSB Watchlist 2018
Map showing the location of the occurrence
Austin Adams joined the TSB’s Air Investigations Branch as a Senior Investigator, Atlantic Region, in September 2017. Prior to that, he worked as a turboprop training pilot at Transport Canada’s Aircraft Services Directorate in Ottawa. He also held various supervisory roles in flight operations, from Chief Pilot to manager of flight training, and has been an Approved Check Pilot for many years.
Mr. Adams has more than 13 800 hours of experience flying with commercial air carriers. He has flown a variety of aircraft including the Dash 8 Q400, Saab 340, Beech 1900 and King Air. He is an active member of the Cadet Instructors Cadre as a Captain and has been involved with the Air Cadet gliding program for more than 20 years as an instructor, tow pilot, and flight safety officer.
Download high-resolution photos from the TSB Flickr page.
Class of investigation
This is a class 2 investigation. These investigations are complex and involve several safety issues requiring in-depth analysis. Class 2 investigations, which frequently result in recommendations, are generally completed within 600 days. For more information, see the Policy on Occurrence Classification.
TSB investigation process
There are 3 phases to a TSB investigation
- Field phase: a team of investigators examines the occurrence site and wreckage, interviews witnesses and collects pertinent information.
- Examination and analysis phase: the TSB reviews pertinent records, tests components of the wreckage in the lab, determines the sequence of events and identifies safety deficiencies. When safety deficiencies are suspected or confirmed, the TSB advises the appropriate authority without waiting until publication of the final report.
- Report phase: a confidential draft report is approved by the Board and sent to persons and corporations who are directly concerned by the report. They then have the opportunity to dispute or correct information they believe to be incorrect. The Board considers all representations before approving the final report, which is subsequently released to the public.
For more information, see our Investigation process page.
The TSB is an independent agency that investigates air, marine, pipeline, and rail transportation occurrences. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil or criminal liability.