Aviation safety investigations & reports

Airbus Industrie A320-211, VH-HYB

Investigation number:
Status: Completed
Investigation completed


The Airbus A320 on a flight from Hobart to Melbourne had commenced descent from flight level (FL) 350 to FL210 when the aircraft cabin altitude began to rise rapidly. The co-pilot was unable to control the cabin pressurisation manually.

The flight crew donned oxygen masks, and the pilot in command requested and was given a clearance by air traffic control for an immediate descent to 10,000 ft. During the descent, the passenger oxygen masks deployed. The aircraft subsequently made an uneventful approach and landing at Melbourne Airport.

The operator found that the electronic control of the pressurisation outflow control-valve had failed, allowing the valve to remain in the fully open position. The valve was changed and the aircraft returned to service. The valve has been returned to the manufacturer in France for further evaluation.

Safety Action

As a result of this occurrence, the Bureau of Air Safety Investigation is currently analysing two possible safety deficiencies. The deficiencies identified involve the use of oxygen masks and emergency descent profile awareness by cabin crew during cabin decompression, and the carriage of additional Passenger Service Unit tools in the mid cabin area of the aircraft.

General details
Date: 08 March 1998   Investigation status: Completed  
Time: 1105 hours ESuT    
Location   (show map): 19 km SSE Wonthaggi, (VOR)    
State: Victoria   Occurrence type: Air/pressurisation  
Release date: 24 July 1998   Occurrence category: Incident  
Report status: Final   Highest injury level: Minor  

Aircraft details

Aircraft details
Aircraft manufacturer Airbus Industrie  
Aircraft model A320  
Aircraft registration VH-HYB  
Serial number 023  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Hobart, TAS.  
Departure time 1023 hours ESuT  
Destination Melbourne, VIC.  
Crew details
Role Class of licence Hours on type Hours total
Pilot-in-Command ATPL 4,000 10,500
  Crew Passenger Ground Total
Minor: 0 13 0 13
Total: 0 13 0 13
Last update 13 May 2014