Air investigations: Incorrect configuration involving Airbus in Sydney
Topics: AIR INVESTIGATIONS AIRBUS SYDNEY
While preparing for the flight and having difficulties with the electronic system used for calculating take-off performance figures, the flight crew reverted to the back-up procedure of manual calculations.
Shortly after take-off, the maximum flap extended speed was exceeded. As the aircraft climbed through 2,800 ft, the flight crew retracted the landing gear after realising it was still extended, resulting in a landing gear retraction overspeed.
In completing the manual calculations for take-off performance, the flight crew inadvertently calculated speeds that were higher than required for the actual aircraft weight and environmental conditions. The incorrect take-off speeds were not identified by independent verification and cross-checking.
During the first segment of the take-off climb period, at maximum engine power settings, the aircraft pitch rate was below the recommended 3° per second, resulting in a higher acceleration rate than anticipated. Due to the incorrect calculated speeds, the aircraft rotated with a margin of only 16 kt to the flap extended limit speed. Five seconds after rotation, the flap extended overspeed event occurred.
The aircraft did not rotate to the correct pitch attitude and the pilot monitoring did not alert the pilot flying of this. However, he called ‘speed, speed’ in an attempt to assist the pilot flying manage the airspeed, to which the pilot flying reduced the engine power in response, rather than increasing the aircraft pitch. The action of reducing the engine power was taken when the aircraft was below the safe altitude above ground.
The landing gear would normally be retracted by the flight crew as soon as the aircraft had a positive rate of climb. In this case, the crew did not retract the landing gear when required. Climbing through 2,800 ft, they identified that the landing gear was still extended while troubleshooting the source of a buffeting noise. They then immediately selected the gear to ‘UP’ without first checking the aircraft speed, resulting in a landing gear retraction overspeed event.
This incident highlights the importance of independent validation and cross-check by the flight crew, in particular for performance speeds and aircraft weight. ■