Investigation Summary
The accident occurred during the second leg of a flight originating in Bradley, Connecticut. During the stopover in Halifax, the aircraft was loaded with 53,000 kilograms of lobster and fish. When calculating the takeoff performance for the departure from Halifax, the crew used a Boeing Laptop Tool (BLT). Investigators determined that the crew likely reused the takeoff weight from the Bradley departure (240,000 kg) instead of the actual Halifax weight (353,000 kg). This led to a commanded thrust setting of 1.30-1.33 EPR and rotation speeds that were dangerously low for the aircraft's actual mass. During the takeoff roll, the pilot attempted to rotate at 130 knots, but the aircraft failed to lift off. Despite increasing pitch and eventually advancing thrust levers to 92% (1.60 EPR) in the final seconds, the aircraft struck its tail twice on the runway. It finally became airborne 670 feet past the end of the paved surface and flew for 325 feet before striking a localizer antenna berm located 300 meters (980 feet) beyond the runway, leading to the total loss of the aircraft and all crew members.
Final Conclusions
The Transportation Safety Board of Canada (TSB) concluded that the primary cause was the use of incorrect takeoff performance data due to a data entry error. Contributing factors included crew fatigue, as the company had no regulations governing maximum duty periods for loadmasters and ground engineers, and the crew had been on duty for nearly 19 hours. The TSB also noted the crew's unfamiliarity with the Boeing Laptop Tool and the lack of a formal process to verify the accuracy of the software's output against manual charts.
Video Analysis
The Laptop Error That Crashed a Boeing 747 | The Crash Of MK Airlines Flight 1602 — A detailed look at how a simple data entry error on a laptop led to the tragic crash of a Boeing 747 cargo plane in Halifax.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Michael Thornycroft
First Officer
Gary Keogh
Flight Engineer
Peter Launder
Relief Captain
David Lamb
Relief Flight Engineer
Steven Hooper
Systems & Failure Modes
Boeing Laptop Tool (BLT)
A software tool used by the crew to calculate takeoff performance data, including V-speeds and Engine Pressure Ratio (EPR) settings, based on weight, weather, and runway conditions.
ILS Localizer Antenna
A ground-based antenna system located beyond the runway end; the aircraft's lower aft fuselage struck the earthen berm supporting this antenna, causing the tail section to separate.
Interesting Facts
- 01The aircraft was 113,000 kg heavier than the weight used for takeoff calculations.
- 02The flight crew had been on duty for approximately 19 hours, while the loadmaster and ground engineer had been on duty for 45.5 hours.
- 03The aircraft was a Boeing 747-200 manufactured in 1980 (MSN 22170/486).
- 04The crash was the fourth accident in the history of MK Airlines.
- 05The post-crash fire took nearly three hours to extinguish.
Safety Actions & Advisories
Flight and Duty Time Regulations
The investigation highlighted the need for stricter regulations regarding maximum duty periods for all crew members, including non-flight deck personnel like loadmasters, to mitigate fatigue.
Cessation of BLT Use
Within two weeks of the accident, MK Airlines issued a Notice to Flight Crew to immediately cease use of the Boeing Laptop Tool (BLT) and use alternate manual procedures until formal approval was obtained.
Revised Load Sheet Procedures
MK Airlines issued a notice requiring that the weight and index for the total number of people on board must be explicitly shown in the 'correction' box of load sheets to ensure crew weight is not omitted from calculations.
Known Controversies & Unanswered Questions
MK Airlines Dispute of Findings
Reference ↗MK Airlines disputed the TSB findings, arguing that the Cockpit Voice Recorder was too damaged to provide definitive evidence of the crew's actions or fatigue levels.