The Australian airline Qantas has been ordered to look again at the way it maintains its aircraft, after a safety audit found its maintenance performance “below the airline’s own benchmarks”.

The Civil Aviation Safety Authority said that it planned to conduct further intensive reviews of Qantas, including a full maintenance audit of one plane of each of the major aircraft type in the Qantas fleet.

The shake-up comes after a series of safety incidents involving Qantas planes, beginning in July when a Boeing 747, en route from London to Melbourne, was forced to make an emergency landing in Manila after an oxygen tank exploded on board, ripping a massive hole in the plane’s fuselage.

Further incidents included an emergency landing in Adelaide when a 767 had a problem with its landing gear, and last month the airline temporarily grounded six of its fleet of 737s when it realised there was an irregularity in safety maintenance records.

The CASA reviews will involve checking all maintenance documentation for each of the planes to see it has been completed, as well as physically examining the aircraft on the ground.

Mick Quinn , CASA's deputy chief executive officer of operations, confirmed that issues had been identified at the airline, once renowned for its safety record.

“CASA has looked carefully at the Qantas maintenance systems and performance and uncovered signs of emerging problems,” Mr Quinn said.

“The review found maintenance performance within Qantas is showing some adverse trends and is now below the airline's own benchmarks.

“By taking action now future safety problems will be avoided. The wide-ranging package of actions CASA has initiated will prevent any downward trend in Qantas maintenance performance.

Despite the recent problems, CASA said that its review did not show that any of the recent safety incidents were linked.

“They were unrelated events - there was no apparent common cause.” said Mr Quinn.

Qantas says it will work closely with CASA to implement any recommendations contained in its review of the airlines engineering and maintenance operations.

Geoff Dixon , the company's chief executive, said Qantas had yet to review CASA's report in detail, after received it only this morning. He said that recent industrial disputes may have affected the airline's performance.

"As we have publicly acknowledged, certain Key Performance Indicators and despatch reliability have been significantly impacted by the industrial dispute between Qantas and the (unions) over past months,'' he said,

"These issues are not about safety or compliance and we are working to bring our network performance back to the standards which have earned us a reputation as one of the best and most reliable airlines in the world.

"These difficulties, while improving, will continue for a few weeks yet as our policy of safety before schedule is sacrosanct.''

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