What happened
On November 15, 2007, an Airbus A3-400-600, registration F-WWCJ, was undergoing ground testing at the Toulouse Blagnac aerodrome. The aircraft was in the delivery phase for a customer, and the specific test involved checking for oil leaks. After a period of engine operation, the technicians restarted the engines to perform a high-power static run.
Approximately three minutes after increasing the thrust to a level of 1.25 EPR, the aircraft began to move forward. The technician in the right seat noticed the movement and attempted to intervene by applying the brake pedals and releasing the parking brake. In an attempt to steer the aircraft, the technician also turned the nose wheel steering. However, the aircraft continued to accelerate, and the nose wheel steering action actually reduced the braking effectiveness by inhibiting the central gear brakes. Thirteen seconds after the initial movement began, the aircraft struck the slope of a blast wall, causing the forward section of the aircraft to break and collapse.
The investigation
The investigation examined the procedures used during the engine tests and the cockpit responses. Investigators found that while official documentation required the use of chocks, they were not systematically used during these types of tests. The investigation also looked into the cockpit dynamics, noting that the technician in the right seat focused on the braking system rather than immediately reducing engine power. The presence of client representatives was also analyzed, as the pressure to complete deliveries can influence operational decisions.
Findings
- The aircraft was performing an unscheduled test involving all four engines at high thrust without the use of wheel chocks.
- The thrust applied was approximately equal to the maximum braking capacity of the parking brake.
- The technician focused on the braking system and failed to reduce engine power during the initial movement.
- Steering the nose wheel during the event inhibited the braking of the central landing gear, contributing to the loss of control.
- Industrial and commercial pressures during the delivery phase contributed to the deviation from established maintenance procedures.