What happened
On the afternoon of March 12, 2003, a Boeing 747-412, registered 9V-SMT, was preparing for a long-haul flight from Auckland International Airport to Singapore. The flight, designated SQ286, was carrying 369 passengers, 17 cabin crew, and 3 pilots.
As the aircraft began its takeoff roll, the captain initiated rotation. During this maneuver, the tail of the aircraft made contact with the runway surface. The strike continued for approximately 490 meters before the aircraft successfully became airborne. During the incident, the aircraft drifted near the edge of the runway, and the crew failed to respond appropriately to a stall warning.
The investigation
Investigators determined that the tail strike was the result of incorrect takeoff performance data. The rotation speed used during the takeoff was 33 knots lower than the 163 knots required for the aircraft's actual weight. This discrepancy occurred because the takeoff weight had been recorded incorrectly, underestimating the aircraft's mass by 100 tonnes.
This transcription error went undetected, leading to a chain of events where the thrust settings were set too low and the takeoff reference speeds were insufficient for the actual weight of the aircraft. The investigation also looked into the aircraft's automated systems and the crew's response to the aerodynamic warnings during the roll.