Qantas Superjumbo tests show engine oil leaks

Tests uncovered oil leaks in three Rolls-Royce engines on Qantas' grounded Airbus A380s, the airline's chief executive officer said today, as engineers tried to zero in on the cause of an engine failure on board one of the carrier's superjumbo jets last week.

Australia's national carrier grounded its six double-decker A380s, the world's newest and largest airliner, after an engine burst minutes into a flight from Singapore to Sydney last week, scattering debris over Indonesia's Batam island.

The plane made a safe emergency landing in Singapore.

Engineers conducted eight hours of extensive checks on each engine over the weekend.

Today, chief executive officer Alan Joyce said engineers discovered oil leaks in the turbine area of three engines on three different A380s.

"The oil leaks were beyond normal tolerances," Mr Joyce told reporters. "So Rolls-Royce and our engineers have looked at what we have gathered as an accepted level and they have passed that threshold."

"All of these engines are new engines on a new aircraft type," he added. "The engines are not performing to the parameters that you would expect with this."

Because of that, he said, all of the airline's A380s will be grounded for an additional 72 hours - at least.

All three affected engines have been removed from the planes for further testing, he said.

"As a consequence, it's now narrowing our focus on that issue," he said.

Lufthansa and Singapore Airlines, the other airlines that fly A380s fitted with Rolls-Royce's Trent 900 engines, also briefly grounded their planes last week but resumed services after completing checks.

The Qantas engineers are working with Rolls-Royce, who manufactured and maintains the engines, as well as Airbus.

Investigators focused their search on a missing piece of turbine from the Rolls-Royce engine.

The Australian Transport Safety Bureau, which is leading an international investigation into the blow-out on the A380, appealed for help from residents of Indonesia's Batam island to find the missing chunk of a turbine disc.

The island was scattered with debris last Thursday when one of the A380's four Trent 900 engines failed minutes into a flight to Sydney, with 466 people aboard.

The engine was quickly shut down and the plane returned to Singapore and safely made an emergency landing.

"The recovery of that disk could be crucial to a full understanding of the nature of the engine failure, and may have implications for the prevention of future similar occurrences," the bureau said in a statement.

It released a photograph of a jagged and bent piece of turbine disc from the Trent 900 engine and asked that anyone who might have found a similar piece should hand it to police.

It said one piece of the shattered engine that had been found on Batam was being sent to Britain for examination by Rolls-Royce engineers, under the supervision of bureau investigators. Extra experts were being sent from Australia to Singapore to examine other debris.

Rolls-Royce Group has said the investigation is in its early stages and that it is too early to draw any conclusions.