Page last updated at 13:57 GMT, Tuesday, 14 October 2008 14:57 UK

Computer fault 'caused jet dive'

Pictures of passengers getting off Airbus at Learmonth Airport (Picture: Channel 9)
It was a terrifying and painful ordeal for passengers and crew

A fault in a computer caused last week's heart-stopping nosedive by a Qantas passenger jet, the Australian Transport Safety Bureau has said.

At least 50 people were hurt, some suffering broken bones, when the Airbus A330-300 plunged more than 300m (1,000ft) over Western Australia.

The ATSB said its inquiries had found a fault in a computer unit that detects the angle at which the plane is flying.

The incident has prompted manufacturer Airbus to issue emergency guidelines.

The ATSB's chief air investigator, Julian Walsh, said its preliminary investigations into the incident had found that one of the plane's three Air Data Inertial Reference Units (ADIRU) had malfunctioned.

The units detect, through sensors, the angle at which the plane is flying against the airstream. In this case, the faulty unit determined the plane was climbing when it was actually in level flight, he said.

Sudden descents

The plane was en route from Singapore to Perth on 7 October with 313 people on board when the incident occurred.

It was cruising at about 11,300m (37,000ft) when it suddenly climbed 60m (200ft). Then, in a period lasting only about a minute, it made two steep descents, falling some 300m in total.


After the incident, passenger Nigel Court said he had looked up to find the two passengers in front of him "had their backs on the ceiling".

Scores of the passengers and crew were injured, and the plane made an emergency landing at a remote airbase near the north-western town of Exmouth.

Mr Walsh said Airbus had issued emergency guidelines to plane operators explaining how to handle a similar incident.

"It is probably unlikely that there will be a recurrence, but obviously we won't dismiss that," he said, according to Associated Press.

"It's important that we investigate to find out what led to those readings within the ADIRU so that we can reduce the chances of that happening in the future," he added.

Spate of mishaps

A full report is due to be released by the ATSB next month.

Last week's incident was the latest in a spate of mishaps and malfunctions for the Australian flag-carrier, which prides itself on its safety record.

In July, a Qantas Boeing 747 flying from Hong Kong to Melbourne was forced to make an emergency landing after an oxygen cylinder caused an explosion which blew a large hole in the fuselage.

That incident is still being investigated.

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