What happened
During the initial climb phase following takeoff, the flight crew encountered a significant mechanical failure involving the engine controls. While attempting to adjust the thrust levers to the appropriate settings, the crew discovered that the left engine's lever was immobile, leaving that engine stuck at maximum power. The pilot in command notified air traffic control of the technical malfunction and requested an immediate return to the departure airport.
During the subsequent landing sequence, the crew faced extreme difficulty managing the asymmetric thrust. While the pilot in command operated the aircraft using the right engine, the co-pilot and a maintenance engineer worked to stabilize the left engine, which remained at high power. The aircraft successfully touched down and proceeded to parking bay number 4, though the left engine continued to operate at full thrust.
After the aircraft reached the bay, the captain engaged the parking brake. However, before the wheels could be chocked, the aircraft surged forward at high speed. The momentum carried the plane through a jet blast fence, ultimately resulting in a collision with the control tower building. The accident resulted in one fatality and six injuries, with three of those injuries classified as serious.
Findings
- A mechanical failure prevented the left engine thrust lever from being moved from its full power position.
- Asymmetric thrust caused the aircraft to move forward uncontrollably after the parking brake was applied.