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Airlines Can Stop ’Intrusive’ Check on Rolls’s Trent 900 Engine
By Howard Mustoe -
Airlines that use Rolls-Royce Group Plc Trent 900 engines, the type that exploded Nov. 4 on an Airbus A380, no longer need to perform “intrusive” inspections on their engines, the European Aviation Safety Agency said.

EASA had asked airlines to inspect the engines for “abnormal oil leaks” after the engine failure on a flight operated by Qantas Airways Ltd. The explosion was probably caused by an oil fire that may have led to the disintegration of the engine’s intermediate pressure turbine disc. An oil feed tube fracture, caused by a thin wall section, probably led to the oil leak and fire, EASA said.
“The latest progress of the on-going investigation, further assessment of manufacturing data and additional stress analysis continue to support the above failure scenario,” the regulator said today in an airworthiness directive on its website. All parts containing the oil tube with a thin wall prone to failure have been removed from service, the agency said.

Rolls-Royce, based on London, developed software to detect conditions that may lead to the engine exceeding a safe speed, and that shuts it down before it reaches a speed at which the disc would burst, the regulator said on Dec. 13. The software and the understanding of the event mean inspections for abnormal oil leakage are “not necessary anymore,” are “intrusive” and could “introduce some risk from possible maintenance errors,” the statement said.

Qantas also reported oil leaks from Trent 900 turbines on Feb. 15 and again on Feb. 24. In the latter incident, pilots idled a Rolls-Royce engine on an A380 flying from Singapore to London, according to a notice posted today on the website of the Australian Transport Safety Bureau.
Qantas said both leaks last month affected different parts of the engine than those involved in the November explosion that forced an emergency landing in Singapore. There were no injuries or damage to the aircraft in either case.
Rolls-Royce fell 16 pence, or 2.6 percent, to 597 pence in London trading, valuing the company at 11.2 billion pounds ($18.3 billion).

To contact the reporter on this story: Howard Mustoe in London at hmustoe@bloomberg.net.
To contact the editor responsible for this story: Benedikt Kammel at bkammel@bloomberg.net