What happened
On 28 July 2011, at approximately 04:11 KST, an Asiana Airlines cargo flight, operating as AAR991, crashed into international waters roughly 130 km west of Jeju International Airport. The aircraft, a B747-400F with registration HL7604, was performing a scheduled flight from Incheon, Republic of Korea, to Shanghai, China.
Shortly after 03:54, the flight crew notified Shanghai Air Traffic Control of a fire in the main deck cargo compartment. Following this report, the crew initiated an emergency descent and requested a diversion to Jeju Airport. During the descent, ACARS messages indicated issues with equipment smoke, cooling, and cargo detection. As the aircraft continued its descent, the crew reported increasingly severe difficulties, including malfunctions with the yaw damper, rudder ratio, and flap controls.
The captain eventually communicated via another aircraft, KAL886, to report that the rudder and flight controls were no longer functional. The crew also noted heavy vibrations that made altitude control impossible. The final communications from the crew included a declaration of an emergency ditching. The aircraft subsequently crashed, resulting in 2 fatalities (the captain and the first officer) and the total destruction of the aircraft.
Findings
- The aircraft experienced an active cargo fire on the main deck.
- The fire led to a progressive loss of critical flight systems, including the rudder, yaw damper, and flight control surfaces.
- Severe structural vibrations occurred during the final stages of flight, rendering the aircraft uncontrollable.