Singapore A333 near Bangkok on Apr 22nd 2013, cargo fire

Last Update: September 3, 2015 / 13:29:02 GMT/Zulu time

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Incident Facts

Date of incident
Apr 22, 2013

Classification
Accident

Airline
Singapore Airlines

Flight number
SQ-446

Departure
Singapore, Singapore

Destination
Dhaka, Bangladesh

Aircraft Registration
9V-STO

Aircraft Type
Airbus A330-300

ICAO Type Designator
A333

9V-STO after opening of cargo doorA Singapore Airlines Airbus A330-300, registration 9V-STO performing flight SQ-446 from Singapore (Singapore) to Dhaka (Bangladesh) with 105 passengers and 12 crew, was enroute at FL350 about 120nm southwest of Bangkok (Thailand) when the crew received a cargo fire indication, activated the cargo fire suppression system and decided to divert to Bangkok. During the descent towards Bangkok a burning smell developed on board of the aircraft. The aircraft landed safely on Bangkok's runway 19R about 20 minutes later. Emergency services responded, the passengers disembarked via stairs, after opening of the aft cargo door a plume of smoke became visible, fire services sprayed the cargo bay and needed more than 2 hours to control the situation. There were no injuries, the cargo was damaged, the damage to the aircraft is being assessed.

The airline confirmed a rear cargo smoke indication prompted the diversion to Bangkok, the aircraft landed safely, no injuries occurred. The passengers were provided with hotel accomodation, were rebooked onto other flights and continued their journey the following day. Thailand's Authorities are investigating, the airline is fully cooperating with the investigation. It is planned to ferry the aircraft to Singapore for further assessment after initial checks are completed.

Passengers reported the crew announced there was a minor problem, however, they needed to divert to Bangkok. The aircraft landed safely with emergency services on stand by and proceeded to the apron, where the passengers disembarked. Only after a large plume of smoke became visible after opening of the cargo bay everyone realised how critical the situation had been.

Thailand's accident investigation board has opened an investigation.

On Jul 1st 2014 Singapore's AAIB released an interim report indicating that the investigation has been delegated to the Singapore AAIB. The AAIB reported that the crew received an aft and bulk cargo smoke indication in flight at FL360 over the Gulf of Thailand about 8nm from Thailand's coast. The crew activated the cargo fire extinguishing agent and diverted to the nearest airport Bangkok. The smoke indication remained active even after the agent had been discharged. The aircraft landed safely on Bangkok's runway 19R, vacated the runway and taxied to a parking bay where emergency services performed an exterior inspection. No smoke or fire was visible from the aft and bulk cargo doors, the passengers disembarked via stairs. The AAIB then continued: "The Bangkok ARFF service tended to the aft cargo compartment where smoke was billowing from the aft cargo door. While unloading cargo container 42L, the contents burst into flames. The ARFF used a combination of water and carbon dioxide to extinguish the fire."

In August 2015 Singapore AAIB's released their final report without a formal conclusion but analysing:

The area of fire origin is most likely in cargo container 42L, although it is not possible to pinpoint the exact location, given the extent of the fire damage of the contents of the container.

While the presence of ethanol, an ignitable liquid which could have fueled the fire, was found by the investigators, the heat source that was needed to ignite the ethanol could not be determined.

The investigation could not establish the source of the ethanol and there was no declared shipment of ethanol based on the description of the consignments.

The three items of dangerous goods as declared in the NOTOC were not involved in the fire event. The investigation is unable to determine if there were undeclared items of dangerous goods involved.

The investigation was unable to determine the exact cause of the fire.

Nevertheless, the incident highlighted the following aspects worth discussing:

- Rekindling of fire
- Communication of dangerous goods
- Communication among ARFS, air traffic controller and the emergency aircraft concerning the status of an emergency
- Flight crew’s decision to terminate the emergency

The AAIB continued analysis: "The fire at cargo container 42L was rekindled after the aft cargo door was opened. This suggested the presence of embers within the contents of cargo container 42L and the rekindling of the fire was triggered by the fresh supply of air despite the spraying, from time to time, of carbon dioxide into the aft cargo compartment by the ARFS. However, the ARFS, which was on standby near the aircraft as the cargo unloading started, reacted quickly when fire rekindled. Any airport fire service should always be ready to respond to the possibility of the rekindling of fire. They should not consider that a firerelated emergency is over unless the necessary fire risk checks have been carried out."

With respect to three items of dangerous goods on board the AAIB analysed: "Although the three declared dangerous goods were not involved in the fire in the aft cargo compartment, information regarding the presence, location and nature of the dangerous goods is vital for a firefighting service to plan for response action. The effectiveness of the response could be compromised without such information."

The AAIB concluded analysis with respect to the first officer terminating the emergency: "After the aircraft had arrived at the bay and in response to a question from the FO, the controller told the flight crew that everything was normal. It is not known whether the controller had checked with the ARFS about the condition at the aft cargo area. The FO might have assumed that the controller had done so. And when the controller asked the flight crew to “report emergency terminated”, the FO somehow concluded that the emergency was over. It would have been more prudent for the FO to consider that the emergency was still not over. It was fortuitous that the PIC intervened to request that the ARFS remain in position to provide fire protection cover for the aircraft until all the persons on board have disembarked and the aft cargo area checked for any further fire risk."