What happened
On 26 July 2011, an Airbus A300B4-605R, registration G-MAJS, was preparing for a scheduled passenger flight from London Gatwick to Chania, Crete. During pre-flight preparations, the crew encountered a technical issue involving a slat system fault on the Electronic Centralized Aircraft Monitor. To resolve the fault, the crew followed the Quick Reference Handbook (QRH) and consulted ground engineers, who suggested that multiple system resets might be necessary. This process involved the co-pilot repeatedly cycling the slats/flaps lever.
Shortly after takeoff, while the aircraft was climbing through 280 feet, the co-pilot inadvertently moved the slats/flaps lever to the 0/0 position. This action triggered the full retraction of the slats and flaps. As the aircraft's angle of attack increased, the stall warning system activated twice. The commander, acting as the pilot flying, responded by reducing the pitch attitude to maintain a positive rate of climb, which allowed the aircraft to accelerate back to normal climb speed. The landing gear remained extended during this period, and the crew subsequently corrected the lever position and raised the gear.
The investigation
The AAIB examined the flight parameters and the crew's actions leading up to the incident. The investigation focused on the movement of the slats/flatt lever and the impact of the preceding technical troubleshooting on the crew's manual dexterity. The investigation also reviewed the functionality of the slat alpha-lock protection system, which is designed to prevent retraction at high angles of attack but does not stop retraction once it has been initiated.
Findings
- The crew had been preoccupied with resolving a slat system fault prior to departure.
- The co-pilot had developed a specific motor skill by cycling the slats/flaps lever directly between 15/15 and 0/0 to clear the fault during ground operations.
- The co-pilot's preoccupation with the slat fault and the mental rehearsal of takeoff procedures led to the inadvertent retraction of the slats and flaps instead of the landing gear.
- The aircraft's alpha-lock protection system functioned as designed, as it did not prevent the initial retraction once the lever was moved at a low angle of attack.