On 9 June 2014, an Airbus A330, registered VH-XFB, took off from Perth, Western Australia, bound for Sydney, New South Wales. As engine power was applied at the commencement of take-off, cabin crew members at the rear of the cabin noticed a burning odour. The crew ultimately traced the source of the fumes to a vent in the rear cabin bulkhead. Some cabin crew members were adversely affected by the fumes and were unable to complete their normal in-flight duties.

Following the flight, engineering staff found that a portion of insulation blanket fitted to the rear pressure bulkhead of the aircraft had collapsed into contact with the Auxiliary Power Unit (APU) bleed air duct, where the duct passes through the rear pressure bulkhead. The blanket wrapping material was damaged and heat affected, exposing the inner glass wool material, which was also heat affected. The engineering investigation determined that the insulation blanket in contact with the bleed air duct was the likely source of the fumes, and that the blanket had not been correctly refitted following maintenance by a previous operator of the aircraft. The operator also found a similar problem on another company A330 aircraft.

As an interim measure, the operator prohibited use of the APU on both aircraft until the insulation blanket adjacent to the APU bleed air ducting was repaired and appropriately restrained in accordance with an Engineering Order. The Engineering Order also required a visual inspection of the rear pressure bulkhead structure immediately around the bleed air duct. The second part of the Engineering Order directed that the insulation blanked be replaced entirely, as a permanent repair. The aircraft manufacturer also made a number of recommendations in response to information supplied by the operator.

Fumes can originate from a wide range of sources. While some fumes may appear subtle and innocuous, they may be the first indication of a serious problem. This incident serves to highlight the importance of treating all fumes with suspicion, and implementing a cautious and conservative response, consistent with published guidance.


Aviation Short Investigations Bulletin - Issue 38