What happened
During the takeoff roll of VH-YIR, a Boeing aircraft, a decrease in the headwind component caused the airspeed to drop and then stagnate as the aircraft accelerated through the rotation phase. This loss of airspeed had the effect of reducing lift and extending the necessary takeoff roll. As the aircraft continued to rotate while the main landing gear remained in contact with the runway, the available tail clearance was significantly reduced, resulting in a tailstrike.
The investigation
Investigators analyzed flight data to determine the precise mechanics of the rotation. The data confirmed that the airspeed variations were not identified or called out by the pilot monitoring, which is a requirement outlined in the flight crew training manual. The investigation also examined the rotation rate, noting that the crew rotated at an average of 2.4° per second to a pitch attitude of 10.55°. While this rate was near the upper limit of recommendations, it was not determined to be a primary cause of the reduced clearance.
Further analysis looked at several other potential factors. The investigation found that the maximum rotation rate of 3.5° per second did not contribute to the event. Additionally, the use of left aileron input to manage crosswinds was deemed insufficient to impact lift or tail clearance. A minor discrepancy between the actual cargo weight and the provided load sheet was also evaluated and found to be insignificant to the occurrence.