What happened
On Thursday, May 22, 2003, at 10:45 AM, a Dyn’aéro MCR 01 aircraft, registered F-PSLF, was preparing for a private flight from AD Compiègne to Auxerre. The weather conditions were excellent, characterized by calm winds and CAVOK visibility.
During the engine start sequence, the engine immediately delivered full power. Despite the pilot applying the brakes firmly, the aircraft began to accelerate across the wet grass. The pilot managed to steer the aircraft away from a nearby hangar, but the plane struck a bump on the terrain and landed violently before coming to a stop with the engine stalled. The incident resulted in damage to the left main landing gear.
The investigation
The investigation focused on the mechanical functionality of the engine and the cockpit controls. Investigators examined the engine and found no anomalies or failures; a subsequent test following manufacturer procedures was successful on the first attempt. The engine shutdown procedure also functioned normally via the ignition key.
An examination of the flight controls revealed no mechanical binding or stiffness. The investigation then turned to the pilot's actions during the start-up. It was determined that the throttle lever was set to the maximum position instead of the idle position at the moment of ignition. The investigation also noted that the aircraft is equipped with hand-operated brakes rather than foot-operated brakes.
Findings
The primary cause of the excursion was pilot confusion between the throttle and the brake controls. Because the throttle and brake levers are identical in shape and located in close proximity to one another, the pilot inadvertently pulled the brake lever while attempting to reduce engine power. This error, combined with the throttle being set to full power during start-up, led to the uncontrolled acceleration.