Smoke event - VH-OTD, 19 km north-east of Sydney Aerodrome, New South Wales, on 9 July 2009

On 9 July 2009, at about 2108 Eastern Standard Time a British Aerospace BAe Jetstream 32 aircraft, registered VH-OTD, was being operated on a scheduled passenger service from Sydney to Williamtown, New South Wales (NSW), with two crew and six passengers.

During climb to 9,000 ft, and about 19 km northeast of Sydney, the flight crew noticed a strong electrical burning smell in the cabin. The flight crew requested and received clearance from air traffic control for an immediate return to Sydney. Faced with a high workload, the crew chose not to don their emergency oxygen masks during the return flight to Sydney.

Following an uneventful landing, the crew noticed a light haze of smoke below the roof of the cabin. After the passengers disembarked, engineering staff located the source of smoke as the weather radar indicator.

Examination of the weather radar indicator found that burning of a control circuit board had occurred, damaging the printed circuit board substrate. The damage was not the result of an aircraft system fault.

Research published by the ATSB has shown that the second most common cause of in-flight medical and incapacitation events was exposure to toxic smoke and fumes. Use of supplemental breathing equipment is an important defense against pilot incapacitation.