SYDNEY // Qantas defended its decision to keep its A380 superjumbos grounded 11 days after a mid-air engine failure prompted a global safety scare, and the airline suffered more problems on Monday when a different type of plane was forced back by an electrical fault.
The latest incident was unrelated to the superjumbo drama, but it was the third time a Qantas jetliner has aborted flights because of faults since the November 4 explosion on the A380.
The Airbus incident has directed attention at Qantas, which prides itself on its safety record. Qantas says the three faults since November 4 were far less serious than problems with the A380 and the turnarounds were precautionary.
The airline said a Boeing 747 carrying 221 passengers and crew turned back an hour into a flight from Sydney headed for Buenos Aires, Argentina, after an electrical fault was detected over the Pacific Ocean. The plane dumped its fuel before landing safely in Sydney, Qantas said.
On Friday, a Qantas Boeing 767 turned back on a domestic flight in Australia after pilots detected abnormal vibrations in one of the plane's two General Electric engines. A week earlier, a Sydney-bound Qantas Boeing 747 landed safely in Singapore after an engine caught fire minutes after take-off.
Both 747 planes were fitted with Rolls-Royce RB211 engines.
The A380 scare is being blamed on a fault in the Rolls-Royce Trent 900 engine. Leaking oil caught fire in the motor of a four-engine Qantas A380, heating metal parts and causing the disintegration over Indonesia before the jetliner returned safely to Singapore. Experts say chunks of flying metal damaged vital systems in the wing of the Sydney-bound plane, causing the pilots to lose control of the second engine and half of the brake flaps on the damaged wing in a situation far more serious than originally portrayed by the airline.
Qantas grounded its six A380s within hours and said four days later that the checks had revealed suspicious oil leaks on three engines on three different grounded A380s. Singapore Airlines and Lufthansa, which both use A380s with Trent 900 engines, have conducted checks on their superjumbos and all but one have returned to service, the airlines say.
Qantas' six planes - the backbone of the airline's longest and most lucrative international routes between Australia and Los Angeles, Singapore and London - remain grounded despite what experts say is financial pressure to fly them again.
"We are taking our normal and extremely conservative approach to safety and will not operate our A380 fleet until we are completely confident that it is safe to do so," Qantas spokesman Simon Rushton said on Monday.
Qantas was still hopeful of returning the A380s to service "in days, not weeks," Rushton said.
Britain's Rolls-Royce Group PLC, the world's second-largest engine maker, said on Friday that it would be replacing an unspecified module, or collection of linked parts, on the Trent 900. Airbus said Rolls-Royce would also be equipping the engines with software to shut them down before an oil leak could cause an engine to disintegrate.
Rushton said three engines had been removed from Qantas A380s as part of a detailed inspection program ordered by Europe's air safety regulator and recommendations by Rolls-Royce. He declined to comment on an unsourced newspaper report that Rolls-Royce had advised Qantas that seven more engines may have to be removed, something that would cause longer delays and potential revenue losses.
Each A380 is fitted with four engines, each of them massive and extremely complex machines.
Singapore Airlines, which grounded three of its 11 A380s after checks found oil leaks in three Trent 900s, said Monday that two were back in service after engine changes and that work was continuing on the third.
Meanwhile, the lead investigator into the Qantas incident said the automatic audio recording of conversations between the pilots during the mid-air emergency had been erased, though this would not be a significant setback.
The Australian Transport Safety Bureau said the plane's voice cockpit recorder ran for more than two hours after the incident because the explosion caused one of the plane's other engines to fail to shut down after it landed, meaning the earlier conversations were overwritten.
The flight data recorder was recovered and includes the entire occurrence, and had provided extensive flight and engine data, the ATSB said. Data from other in-flight recorders was also being analysed.
"Despite initial difficulties as a result of damage to the aircraft's electrical system, the ATSB, in collaboration with Airbus, Qantas, the Air Accident Investigation Bureau of Singapore and the aircraft condition monitoring system manufacturer, have successfully recovered all pertinent data," the ATSB said in a statement.