In-flight engine fuel leak, Nadi, Fiji, Boeing 747-438, VH-OJD

While on a scheduled passenger flight from Brisbane, Australia, to Los Angeles, US, the crew of the Boeing Company 747-438 aircraft, registered VH-OJD, observed excessive fuel use by the number three engine. After confirmation that the engine had a fuel leak, the flight crew conducted and in-flight engine shutdown and diverted the aircraft to Sydney.

Inspection of the engine found a fuel manifold drain line had fractured. Detailed examination of the drain line revealed that it had been subjected to high cycle fatigue (HCF), which led to its failure. The HCF was attributed to harmonic resonance from a combustor rumble of unknown origin.

As a result of extensive testing of the engine, the manufacturer redesigned the drain line and reviewed its attachment (clipping) arrangements.