History of the Flight
On 22 April 2013, an Airbus A330 (registration 9V-STO) operated by Singapore Airlines as Flight SQ446 from Singapore Changi Airport to Dhaka, Bangladesh. The aircraft took off at 1858 hrs Singapore time. Approximately 84 minutes into the flight, while cruising at 36,000 feet over the Gulf of Thailand about 8.1 nautical miles off the coast of Thailand's Prachuap Khiri Khan province, the flight crew received a smoke warning indicating a problem in the rear cargo compartment. The rear cargo compartment comprised an aft cargo compartment for containers and pallets and a bulk cargo compartment separated by a cargo net.
Shortly before the warning, the First Officer detected a slight burning smell from the ventilation blowers. The Electronic Centralised Aircraft Monitor (ECAM) displayed an "AFT/BULK CRG SMOKE" warning accompanied by a continuous chime. A cabin attendant reported that passengers near Door 3 Left also detected a burning smell. The flight crew discharged fire extinguishing agent into the cargo compartments as per the ECAM checklist.
The Pilot-in-Command decided to divert to Suvarnabhumi Airport in Bangkok, the nearest suitable airport. The crew declared MAYDAY with Bangkok Approach and reported 117 persons on board, 35,000 kg of fuel remaining, and dangerous goods on board. The aircraft landed uneventfully on Runway 19R at 2053 hrs (1953 hrs Thailand time) and stopped on the runway.
Post-Landing Events
Upon landing, the flight crew requested the Airport Rescue and Firefighting Service (ARFS) to inspect the aircraft for smoke. After a visual external inspection found no signs of smoke or fire, the aircraft taxied to a parking bay. The emergency was not terminated until all occupants had disembarked and the cargo area could be inspected. Once the passengers and crew had vacated via passenger stairs, white smoke billowed out when the aft cargo door was opened. The ARFS discharged carbon dioxide into the compartment. During unloading of the cargo container at position 42L, its contents burst into flames, which the ARFS extinguished.
Damage and Injuries
There were no injuries in this incident. The contents of cargo container 42L sustained significant damage. Exterior surfaces of other containers and pallets in the aft cargo compartment showed varying degrees of singeing. Aircraft damage was limited to the sidewall and ceiling panels of the aft cargo compartment, and installations on the ceiling.
Investigation and Safety Recommendations
The Air Accident Investigation Bureau (AAIB) of Singapore conducted the investigation. The report discussed observations related to the rekindling of the fire, communication regarding dangerous goods, and coordination between ARFS, air traffic control, and the flight crew. However, no probable cause was stated. The investigation resulted in safety recommendations (not detailed in this summary) aimed at improving procedures.