Hong Kong’s Air Accident Investigation Authority has found no accident-related technical defect in the components examined so far after an ACT Airlines Boeing 747-481 BDSF veered off the runway at Hong Kong International Airport. The TC-ACF freighter, operated for Emirates SkyCargo, struck a parked airport security vehicle and entered the sea during its landing roll on 20 October 2025, killing two security personnel.
Investigators are focusing on the forward movement of the No. 4 engine thrust lever, which caused the aircraft to turn left and leave the runway. Examinations of relevant flight-control, engine and associated components by manufacturers and specialists have not identified a mechanical failure linked to the accident.
The cause of the lever movement remains unresolved. The investigation is examining whether it was produced by the electromechanical autothrottle system or by an external force. A specialist spectrum analysis of the cockpit voice recording is planned, together with flight tests or simulator work to reconstruct the aircraft’s behaviour during the landing roll.
The authority has recovered wreckage, reviewed flight and cockpit recorder data, and gathered information from the operator, weather service, air traffic control and airport. The investigation remains open, and the final report is expected by the end of 2026. The interim findings do not establish the accident’s cause.