Aviation safety investigations & reports

Fuel system event - Boeing 737-7BX, VH-VBR, Near Rockhampton aerodrome, Qld, 13 August 2007

Investigation number:
Status: Completed
Investigation completed


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On 13 August 2007, a Boeing 737-700 aircraft, registered VH-VBR, was operating on a scheduled flight from Brisbane to Hamilton Island, Qld. On reaching cruise altitude, the flight crew became aware of a fuel imbalance situation due to fuel loss from the number-2 (right) engine. At 1311 Eastern Standard Time and approximately 148 km SE of Rockhampton, Qld, the crew conducted an in-flight shut down of the right engine. The aircraft was subsequently diverted to Rockhampton where a single-engine approach and landing was completed without further incident.

Examination identified the leak as being from the main fuel return pipe where it connected into the oil/fuel heat exchanger. The pipe connection was of flanged plate design, held in position by four bolts tightened into threaded inserts on the oil/fuel heat exchanger body. The threaded inserts had failed, pulling free of the heat exchanger body.

The investigation found that the failure of the inserts was the result of over tightening that had occurred during previous maintenance. The oil/fuel heat exchanger was subject to two different modification states, each requiring different fuel return pipe bolt torque values.

As a result of this occurrence, the aircraft operator notified the subsequent maintenance provider of the incident and received assurance that their process, procedures and oversight were adequate to prevent a recurrence.

Download Final Report
[Download  PDF: 1.16MB]
General details
Date: 13 August 2007   Investigation status: Completed  
Time: 1311 EST   Investigation level: Systemic - click for an explanation of investigation levels  
Location   (show map): 148 km SE Rockhampton    
State: Queensland   Occurrence type: Fuel systems  
Release date: 14 April 2009   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft details

Aircraft details
Aircraft manufacturer The Boeing Company  
Aircraft model 737  
Aircraft registration VH-VBR  
Serial number 30745  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Brisbane, Qld  
Departure time NA  
Destination Hamilton Island, Qld  
Last update 03 April 2020