Singapore Airlines has said it replaced three Trent 900s. Lufthansa replaced one but said the reason was unrelated to the Qantas blowout.
Singapore Airlines hasn't been told how many of its Rolls Royce engines need to be replaced, and is continuing to fly all of its A380s in the meantime, the airline's Vice President for Public Affairs Nicholas Ionides said.
Lufthansa spokesman Thomas Jachnow said the German airline will only have to change one of its Trent 900 engines. "The talks are over now with Rolls Royce and Lufthansa, and the result is that we are lucky - only one engine neds to be changed," Jachnow said.
Rolls-Royce said Friday that it would be replacing modules, or sections of linked parts, aboard Trent 900 engines that were found to have oil leaks, but provided no other details.
Joyce said Rolls-Royce had ordered modifications on parts of the Trent 900 engines and indicated it had done so before the Nov. 4 incident. But there was no early indication to Qantas that the modification was significant.
"Rolls-Royce have gone and modified certain parts of this engine," he said. "If this was significant and was known to be significant, we would have liked to have known about that ... We and Airbus weren't aware of it.
"But it depends on what the purpose of modifications were for," Joyce added. "It doesn't look like it's a significant modification, but it is a modification that has an impact on how the engines are performing. And it is a modification that indicates whether you are going to have a problem or not with the engine."
Airbus has said new Trent 900s coming off the production line should not have the oil leak problem, but says the changes were ordered after the Qantas incident. It has denied an Australian newspaper's report that an Airbus executive said Rolls-Royce started making changes to some versions of the engine before Nov. 4.
Joyce said the normal procedure for nonurgent modifications ordered by an engine manufacturer is to make the change when the engine is next brought in for routine maintenance.
"If this incident hadn't occurred, eventually all these engines would have had this modification," he said. "Now, because it is an indicator, we are not taking any risks. We're taking the engines off and making sure this modification is in place before the engines are put back on the aircraft."
The other airlines that fly A380s, Dubai's Emirates and Air France, use engines built by Engine Alliance, a 50/50 joint venture between GE Aircraft Engines and Pratt & Whitney.
Airbus has received orders for 234 of its A380s, which sell for list price of $346.3 million. A total of 38 of the aircraft have been delivered. Emirates and Qantas are the biggest customers for the jet, with 58 and 20 total orders so far.
In the first nine months of the year, Airbus delivered 14 A380s and took in 32 new orders.
Associated Press Writers Christopher Bodeen in Zhuhai, China, Rod McGuirk in Canberra, Australia, Alex Kennedy in Singapore and David Rising in Berlin contributed to this report.
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Engineers have discovered oil leaks in the turbine area of three engines on three different A380s.
Rolls-Royce has identified a faulty bearing box as the cause of the oil leak problem.
Rolls-Royce congratulates German flag-carrier Lufthansa on the delivery of its first Airbus A380 aircraft.