Asiana Cargo flight OZ991 (a Boeing 747-400F, HL7604), was a scheduled cargo flight from Incheon International Airport, Incheon, Republic of Korea, to Shanghai Pudong International Airport, Shanghai, China, that crashed into the international waters about 130 km west of Jeju International Airport after the flight crew reported a cargo fire to Shanghai Area Control Center (SHI ACC) near a reporting point SADLI on airway A593 about 03:54 and attempted to divert to Jeju International Airport.
The aircraft was a scheduled international cargo flight operating under the instrument flight rule in accordance with the Korean Aviation Act and the Convention on International Civil Aviation.
Aboard the aircraft were two pilots. The two pilots were fatally injured, and the aircraft was destroyed.
Asiana Cargo flight OZ991 crashed 1 hour 8 minutes after takeoff and about 18 minutes after the mayday declaration when it attempted to divert to Jeju Airport.
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.
- 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.
- 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.