BERLIN – Rolls-Royce modified a problematic section on new models of its engine for the world's largest jetliner months before one caught fire and blew apart over Indonesia, a Lufthansa spokesman said Thursday.
The chief executive of Qantas, meanwhile, said Rolls-Royce had made modifications to the Trent 900 engine without telling the airline or Airbus, which makes the A380 superjumbo.
The officials' remarks were the strongest indication yet that Rolls-Royce had addressed a defect in new models of the engine while allowing Airbus A380 superjumbos to continue flying with unmodified older models.
Lufthansa's first A380, delivered by Airbus on May 19, had three newer versions of the Trent 900 engine and one older version, airline spokesman Thomas Jachnow said.
"When we got our first aircraft it was curious that one was from an older one and three were totally new from the production line," Jachnow said. "I think this is more or less the cusp where the old to new happened."
Engine modifications are common in the industry, and Qantas CEO Alan Joyce said it "doesn't look like" the changes made to the Trent 900 were significant. But he added that to make that determination it's important to know why the changes were made.
"If this was significant, and was known to be significant, we would have liked to have known about that," Joyce said. "We and Airbus weren't aware of it."
Airbus declined to say whether it was aware of earlier changes by Rolls-Royce, but like Qantas it indicated it would be seeking compensation from the London-based engine maker for the problems with the Trent 900.
Rolls-Royce declined repeated requests to comment on what it knew about the specific defect before the Nov. 4 accident, which sent metal rocketing into the wing of a Qantas plane as it flew over Indonesia. The disintegrating engine damaged one of the beams that attaches the wing to the plane, cutting control lines, piercing fuel tanks and setting off a cascading series of critical system failures.
Europe's air-safety regulator said on Nov. 10 that airlines should inspect several parts around one of the Trent 900's turbines in order to prevent the type of oil leak and fire that broke out on the Qantas flight. Rolls-Royce said Nov. 12 that it will be changing a module, or sections of linked parts, on the Trent 900.
Jachnow, of Lufthansa, said the module that needs replacing was found in only one of the German airline's engines, and that all the others had been delivered with the newer module.
He added that Lufthansa has had no difficulties with any of its A380 engines and that the one with the older module is still in service, though it will be swapped out when Rolls-Royce delivers a replacement.
Joyce told reporters Qantas may have to replace 14 of its Trent 900 engines, each of which is worth about $10 million. Worldwide, 80 Trent 900s power 20 A380s flown by three airlines, and Joyce said as many as half of those engines may need to be replaced.
Rolls-Royce has indicated that the number of engines that needed to be replaced was "40 engines worldwide," Joyce said. An Airbus spokesman said he could not confirm that figure.
Rolls-Royce stock was up 0.7 percent at 6.03 pence ($9.67) on the London Stock Exchange, a sign that investors were happy to have some clarity.
Lufthansa flies three A380s with Trent 900 engines, and Singapore Airlines flies 11 of the four-engine superjumbos. Singapore Airlines declined to comment on whether it may have to change as many as 25 engines.
Other airlines' A380s use a U.S. conglomerate's engine.
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. "Rolls Royce have gone and modified certain parts of this engine ... and aircraft manufacturers and engine manufacturers will do that," he said.
A European air-safety official said last week that Rolls-Royce would be providing new engines to airlines as temporary replacements for ones that need modification. Airlines typically keep some spares, and Airbus has also raised the prospect of using engines meant for new planes as temporary replacements.
The sudden need for dozens of new engines, even temporarily, could cause delays in deliveries of new A380s. Analysts, however, said that delays would probably not be severe.
Airbus spokesman Justin Dubon said next year's schedule for A380 deliveries depended on the Rolls-Royce situation.
"We expect to have a much better idea in the next 3 to 4 weeks," Dubon said.
Sandy Morris, aerospace analyst at RBS Securities in London, said Airbus told investors last week that some jets due to be delivered in the first half of next year might be delivered in the second half.
Dubon declined to say if or when A380s had begun to be outfitted with a new model of Trent 900 engines.
"As with any other manufacturer, they continually update the build standards," Dubon said of Rolls-Royce.
Weissenstein reported from London. Rohan Sullivan in Sydney, Greg Keller in Paris and Jane Wardell in London contributed to this report.