Aviation safety investigations & reports

Incorrect configuration involving Boeing 737, VH-VUB, near Sydney, NSW, on 12 July 2018

Investigation number:
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

On 12 July 2018, the crew of a Boeing 737-8FE, registered VH-VUB was preparing for its flight from Sydney to Melbourne. During pre-flight preparation, the crew did not correctly configure air conditioning pack switches and did not identify the error following take-off. Consequently, the aircraft did not pressurise as expected and the Cabin Altitude warning presented as the aircraft passed 13,500 ft. The crew identified that the pack switches were OFF, reset them to AUTO and descended to 10,000 ft. After a short time, cabin pressurisation was under control and the crew continued the flight to Melbourne.

What the ATSB found

The ATSB found that the incorrect configuration of the pressurisation system resulted in the cabin altitude rising above 10,000 ft. Normal procedures and checklists, which were designed to ensure that the aircraft is correctly configured for flight, were not completed due to a number of factors, including training, distraction, high workload, low expectancy of error and supervision lapses.

What's been done as a result

The operator published a summary of the occurrence in an internal safety publication. They also issued a flight crew notification and conducted a roadshow to remind flight crew of the importance of standard operating procedures and checklist discipline. The operator is reviewing the checklist and is considering an additional check of packs/pressurisation during the climb. The operator has also introduced a flight operations safety assurance program, additional pressurisation event training and amended its training program to ensure continuity for trainee pilots.

Safety message

Flight crews are reminded that effective checklist management is essential for verifying that critical procedural items are undertaken and ensuring safe aircraft operation. Consequently, it is important to prioritise checklists appropriately and avoid conditions that may introduce potential errors or omissions. Flight crews are also reminded to use all available means for verifying correct system configuration and operation.

Download final report
[Download  PDF: 836KB]

The occurrence


Safety analysis


Safety actions

Sources and submissions


General details
Date: 12 July 2018   Investigation status: Completed  
Time: 1142 AEST   Investigation level: Defined - click for an explanation of investigation levels  
Location   (show map): near Sydney Airport   Investigation phase: Final report: Dissemination  
State: New South Wales   Occurrence type: Incorrect configuration  
Release date: 30 September 2019   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer The Boeing Company  
Aircraft model 737-8FE  
Aircraft registration VH-VUB  
Serial number 34013  
Operator Tiger Airways Australia  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Nil  
Departure point Sydney, New South Wales  
Destination Melbourne, Victoria  
Last update 30 September 2019