Another Qantas ADIRU mishap
"Australia's air safety watchdog is now investigating two in-flight system malfunctions on Qantas jets.
In the latest incident, on December 27, a Qantas Airbus A330-300 destined for Singapore was forced to return to Perth after the autopilot disconnected.
The malfunction occurred while the jet was cruising at 36,000 feet about 500km north-west of Perth.
'The crew elected to return to Perth and an uneventful overweight landing was conducted,' the Australian Transport Safety Bureau (ATSB) said in a statement.
It says the incident is 'similar' to one that occurred in October last year and will be investigated as part of the inquiry into that emergency.
. . .
The air safety watchdog is focusing on a flight computer system component called an ADIRU - air data inertial reference unit.
When the autopilot disconnected on December 27, the crew received a message indicating a problem with the plane's number 1 ADIRU.
They then followed revised guidelines from Airbus issued after the October emergency." - aap