Date & Time: Sep 3, 2010 at 1941 LT
Type of aircraft:
Boeing 747-400
Flight Type:
Hong Kong - Dubai - Cologne
Flight number:
Crew on board:
Crew fatalities:
Pax on board:
Pax fatalities:
Other fatalities:
Total fatalities:
Captain / Total flying hours:
Captain / Total hours on type:
Copilot / Total flying hours:
Copilot / Total hours on type:
Aircraft flight hours:
Aircraft flight cycles:
22 minutes after takeoff from Dubai, while overflying Persian Gulf at FL320, crew declared an emergency and elected to return to Dubai due to smoke in the cabin. On approach to Dubai, aircraft overflew the airport at 4,500 feet and continued towards the south. It eventually crashed 9NM south, on Minhad military area and hit the ground in a pitch angle of 7° and at a speed of 270 kts. Both pilots were killed. Weather conditions were good at the time of the accident.
Probable cause:
Probable causes:
- A large fire developed in palletized cargo on the main deck at or near pallet positions 4 or 5, in Fire Zone 3, consisting of consignments of mixed cargo including a significant number of lithium type batteries and other combustible materials. The fire escalated rapidly into a catastrophic uncontained fire.
- The large, uncontained cargo fire, that originated in the main cargo deck caused the cargo compartment liners to fail under combined thermal and mechanical loads.
- Heat from the fire resulted in the system/component failure or malfunction of the truss assemblies and control cables, directly affecting the control cable tension and elevator function required for the safe operation of the aircraft when in manual control.
- The uncontained cargo fire directly affected the independent critical systems necessary for crew survivability. Heat from the fire exposed the supplementary oxygen system to extreme thermal loading, sufficient to generate a failure. This resulted in the oxygen supply disruption leading to the abrupt failure of the Captain’s oxygen supply and the incapacitation of the captain.
- The progressive failure of the cargo compartment liner increased the area available for the smoke and fire penetration into the fuselage crown area.
- The rate and volume of the continuous toxic smoke, contiguous with the cockpit and supernumerary habitable area, resulted in inadequate visibility in the cockpit, obscuring the view of the primary flight displays, audio control panels and the view outside the cockpit which prevented all normal cockpit functioning.
- The shutdown of PACK 1 for unknown reasons resulted in loss of conditioned airflow to the upper deck causing the Electronic Equipment Cooling [EEC] system to reconfigure to “closed loop mode”. The absence of a positive pressure differential contributed to the hazardous quantities of smoke and fumes entering the cockpit and upper deck, simultaneously obscuring the crew’s view and creating a toxic environment.
- The fire detection methodology of detecting smoke sampling as an indicator of a fire is inadequate as pallet smoke masking can delay the time it takes for a smoke detection system to detect a fire originating within a cargo container or a pallet with a rain cover.
Contributing Factors:
- There is no regulatory FAA requirement in class E cargo compartments for active fire suppression.
- Freighter main deck class E fire suppression procedures which relay on venting airflow and depressurisation as the primary means of controlling a fire are not effective for large Class E cargo fires involving dangerous goods capable of Class D metal fire combustion.
- No risk assessment had been made for the failure of the cargo compartment liner based on the evolution of cargo logistics and associated cargo content fire threats, cargo hazards and bulk carriage of dangerous goods.
- The regulation standards for passive fire suppression do not adequately address the combined total thermal energy released by current cargo in a large cargo fire and the effect this has on the protection of critical systems.
- FAA and EASA regulatory requirements do not recognize the current total fire risk associated with pallets, pallet covers and containers as demonstrated by the NTSB/FAA testing.
- Class 9 Hazmat packing regulations do not address the total or potential fire risk that can result from lithium battery heat release during thermal runaway. Although non-bulk specification packaging is designed to contain leaks and protect the package from failure, the packaging for Class 9 does not function to contain thermal release.
- The growth rate of container and pallet fires after they become detectable by the aircraft’s smoke detection system can be extremely fast, precluding any mitigating action and resulting in an overwhelming total energy release and peak energy release rate for a standard fire load that cannot be contained.
- The course to return to Dubai required a series of complex radio communication relays due to the Pilot Flying’s inability to view and tune the radio transceivers.
- The relay communication between the Pilot Flying, relay aircraft and the various ATC stations resulted in communication confusion, incomplete and delayed communications, which contributed to the escalated workload and task saturation for the Pilot Flying.
- The Fire Main Deck non-normal checklist in the QRH was not fully completed by the crew or adhered to regarding the fire suppression flight level or land at nearest airport instruction.
- Task saturation due to smoke and multiple systems failures prevented effective use of the checklist by the crew.
- Communications between the ATCO units involved multiple stages of information exchange by landline and the destination aerodrome was not fully aware of the specific nature of the emergency, the difficulty that the Pilot Flying was experiencing or the assistance required.
- The Pilot Flying had not selected transponder code 7700, the emergency code, when radio communication with the destination aerodrome was not established.
Final Report:
N571UP.pdf8.41 MB