Narrative:A Boeing 747-400F cargo plane, HL7604, was destroyed when it crashed into the sea off Jeju, South Korea. Both pilots were killed in the accident.
Asiana Airlines flight 991 departed Seoul-Incheon International Airport (ICN) at 03:05 on a cargo flight to Shanghai-Pudong International Airport (PVG), China.
At 03:51, at about FL230, the copilot contacted Shanghai Area Control Center (ACC). Three minutes later the copilot radioed an emergency, requesting an emergency descent due to an on board fire. In subsequent communication the copilot stated that they wanted to divert back to Jeju with a descent to FL100. He also reported a rear cargo fire.
At 04:05 the crew of Korean Air flight KE886 relayed radar vectors and descent instructions from Incheon ACC. The captain then reported rudder control problems to KE886. Control problems appeared to worsen as the captain radioed: "Rudder control... flight control, all are not working." at 04:09. The first officer added: "We have heavy vibration on the airplane, may need to make an emergency landing, emergency ditching.". Last contact was at 04:10 when the first officer radioed: "Altitude control is not available due to heavy vibration, going to ditch... ah." According to radar data the altitude at that time was about 10.000 feet.
The airplane then entered a high speed descent and struck the surface of the sea and broke up. The wreckage sank to a depth of about 85 metres.
The plane carried 58 tonnes of cargo, including 0.4 tonnes of potentially risky materials such as lithium batteries, paint, amino acid solution and synthetic resin.
The Aviation and Railway Accident Investigation Board (ARAIB) determines the cause of this accident as follows:
A fire developed on or near the pallets containing dangerous goods but no physical evidence of the cause of the fire was found. The fire rapidly escalated into a large uncontained fire, and this caused some portions of the fuselage to separate from the aircraft in midair, thereby resulting in the crash.
1. Flammable materials like photo-resist (Class 3) were loaded in position ML, and flammable materials like paint, photo-resist, corrosive liquid, and lithium-ion batteries (Class 9) were loaded on one pallet in position PR.
2. It was difficult to contain a large scale of fire only by the fire suppression system of a Class E cargo compartment that was not equipped with an active fire suppression system.
Loss of control
» Korean Ministry of Transport
Official accident investigation report
Follow-up / safety actions
Altitude and speed before the crash
This map shows the airport of departure and the intended destination of the flight. The line between the airports does not
display the exact flight path.
Distance from Seoul-Incheon International Airport to Shanghai-Pudong International Airport as the crow flies is 817 km (511 miles).