The ATSB has released its second interim factual report on the flight upset of Qantas A330-300 VH-QPA off the coast of Western Australia on October 1 2008, and notes that it is continuing its investigations into what may have prompted one of the aircraft’s computers to output erroneous data, which prompted the upset.
The event occurred when one of the A330’s air data inertial reference units (ADIRU) began to output erroneous data spikes on the aircraft’s angle of attack, prompting the flight control system to command pitch-down movements.
As such, the investigation so far has focused on trying to replicate the data spikes on the ADIRUs, including conducting a flight around the Harold E Holt Naval Communication Station near Learmonth to test if communications from the station could have caused the spikes. However, this did not yield any results, and investigations are continuing along other lines of enquiry.
Cabin safety is also being investigated, based largely on interviews and medical reports of the 119 passengers injured in the upset, with a focus on the use of seatbelts while in cruise. The Bureau noted that passengers should fasten their seatbelts at all times when seated.
The ATSB says that it expects to release a final report on the accident in the second quarter of 2010.