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ASN Wikibase Occurrence # 200408
Last updated: 15 October 2021
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Type:Silhouette image of generic A320 model; specific model in this crash may look slightly different
Airbus A320-216
Owner/operator:Indonesia AirAsia
Registration: PK-AXD
MSN: 3182
Fatalities:Fatalities: 0 / Occupants: 152
Other fatalities:0
Aircraft damage: None
Category:Serious incident
Location:north of Perth, WA -   Australia
Phase: En route
Nature:Passenger - Scheduled
Departure airport:Perth Airport, WA (PER/YPPH)
Destination airport:Denpasar-Ngurah Rai Bali International Airport (DPS/WADD)
Investigating agency: ATSB
Indonesia AirAsia flight QZ535, an Airbus A320, initiated an emergency descent from flight level FL330 to 10,000 ft. during a flight from Perth, Australia, to Bali, Indonesia.
Earlier at about 11:22, the aircraft departed Perth Airport, with two flight crew, four cabin crew and 146 passengers on board. On departure, the flight crew were issued with a clearance from air traffic control to climb to FL 340. At about FL 250, the crew noticed a system 1 (SYS 1) fault for the pressurisation system appear and then disappear. At about 11:48, just after passing FL 300, the master caution activated for the opening of the pressurisation system safety valve(s) (SAFETY VALVE OPEN). The flight crew selected manual control (MAN) for the pressurisation system and, noting a cabin pressurisation rate of climb of 1,100 ft per minute, they attempted to close the outflow valve to reduce the cabin rate of climb. The first officer also noted the cabin differential pressure was 8.3 pounds per square inch and the cabin altitude was 8,900 ft. Before the checklist actions could be completed the master caution cleared.

At about 11:51, the master warning activated intermittently for a high cabin altitude. The excess cabin altitude warning (EXCESS CAB ALT) initially activated intermittently and then remained on.

At about this time, the cabin crew noted intermittent activations of the cabin seat belt signs and emergency lighting. The flight crew informed the cabin crew manager that they were going to conduct an emergency descent, donned their emergency oxygen masks and started the descent. Shortly after, the cabin crew manager reported to the flight crew that the emergency oxygen masks in the cabin were not deployed and the flight crew then manually deployed them. The cabin crew reported that they secured the cabin and instructed the passengers in accordance with their emergency descent procedures.

The flight crew informed air traffic control that they were conducting an emergency descent with pressurisation problems and requested a clearance to return to Perth Airport at 10,000 ft. After some initial communications difficulties, air traffic control issued the respective clearances for a descent to 10,000 ft and return to Perth Airport where the aircraft landed safely at about 12:48.

Some of the crew members reported some ear discomfort just prior to the emergency descent, but none reported any indications of hypoxia. During the descent there was an intermittent activation of the master caution for cabin low differential pressure (LO DIFF PR).
There were no reported injuries and the aircraft was not damaged. The post-flight maintenance tests identified the cabin pressure controller 1 as at fault.



Photo of PK-AXD courtesy

Perth (YPPH / PER)
7 July 2018; (c) Kurt Finger

Revision history:

15-Oct-2017 18:38 harro Added
17-Dec-2017 08:43 AF5541 Updated [Total occupants, Source, Narrative]
17-Dec-2017 08:48 harro Updated [Source, Damage, Narrative]

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