Description

On 7 October 2008, an Airbus A330-300 being operated by Qantas on a scheduled passenger flight from Singapore to Perth, Western Australia was in the cruise at FL370 with the AP engaged when one of the air data inertial reference units (ADIRUs)[1] malfunctioned and two sudden uncommanded pitch downs followed. A PAN, later upgraded to a MAYDAY after the extent of occupant injuries became apparent, was declared to ATC and a diversion to Learmonth initiated with an approach and landing there about an hour later. Of the 315 occupants, 11 passengers and 1 cabin crew member were seriously injured and a further 99 passengers and 8 cabin crew received minor injuries.

Investigation

An Investigation was carried out by the Australian Transport Safety Bureau (ATSB). Flight Data Recorder (FDR), Quick access recorder (QAR) and Cockpit Voice Recorder (CVR) data was all successfully replayed to support the Investigation. A Preliminary Report and two Interim Factual Reports were published whilst the Investigation was in progress.