What happened
On 24 June 2024, at approximately 10:30 UTC, an Airbus A330-200, registration 9M-MTW, operated by Malaysia Airlines Berhad, experienced a loss of cabin pressurization. The aircraft was performing flight MAS780 from Kuala Lumpur International Airport to Suvarnabhumi Airport with 179 people on board. While cruising at flight level 40,000 (FL400), the depressurization event occurred approximately 11 nautical miles from Hat Yai International Airport.
In response to the loss of pressure, the flight crew performed an emergency descent and utilized oxygen masks. During the event, it was noted that the passenger cabin oxygen masks failed to deploy automatically, and the crew did not manually deploy them for the passengers. The aircraft subsequently returned to Kuala Lumpur International Airport for landing. There were no injuries or fatalities, and the aircraft sustained no damage.
The investigation
The Thai Aircraft Accident Investigation Committee notified the French Republic, as the State of Design and Manufacture, and the International Civil Aviation Organization (ICAO) regarding the incident. The investigation is currently in the draft final report phase, with authorities working to determine the technical cause of the depressurization and the failure of the passenger oxygen mask deployment system.