The European Aviation Safety Agency (EASA) told airlines in an Aug. 4 directive to conduct additional checks on the Trent 900 after it found “wear, beyond engine manual limits” on certain parts, an EASA spokesman said.

Qantas chief executive Alan Joyce said the Singapore incident may have been caused by a design issue with the engine, while Airbus parent EADS told A380 operators using Rolls-Royce engines to have them inspected.

“I doubt these checks will differ from the usual maintenance and safety checks they do on these engines,” said Jeff Jupp, a fellow of Britain’s Royal Academy of Engineering and a former Airbus technical director.

“Engineers will make immediate visual checks with a boroscope, which allows them to look inside the engine physically for signs of wear. They may also dismantle the engine.”

An EASA spokesman said directives like the Aug. 4 one were issued regularly and the agency did not see a link between the directive and the Qantas engine failure.

On Thursday, Rolls-Royce advised A380 operators to perform safety checks on its Trent 900 engines.

“This seems like a routine problem that was picked up in maintenance and led to a directive for engine inspections and repair if necessary,” said Jupp. “I very much doubt if the incident was caused by anything fundamental to the architecture of the engine.”

Rolls-Royce said the investigation was at an early stage and it was “important to get the facts” before making any decisions.

Its shares, which fell 3.2 percent on Thursday, were down 2.4 percent at 607 pence at 1125 GMT. EADS shares were 0.4 percent lower at 18.17 euros following Thursday’s 2.6 percent decline.

A Qantas A380 had to make an emergency landing in Singapore on Thursday, following the failure of one of its four Trent 900 engines, prompting Qantas and Singapore Airlines to suspend all A380 flights.

“Rolls-Royce’s Trent family of engines are very similar but differ in terms of the power they can produce, with the bigger models such as the Trent 900 able to deliver more power,” Howard Wheeldon, senior strategist at BGC Partners.

“Perhaps these engines have now been taken to the absolute extreme of what they can do, especially given the suggestion that the parts are wearing faster than they should.”

Thursday’s emergency was the third time a Rolls-Royce powered A380 experienced problems during a flight.

In August, a Lufthansa A380 on route to Tokyo from Frankfurt had to shut down a one of its four Trent 900 engines shortly before landing because of a change in oil pressure, while a Singapore Airlines A380 flight had to turn back to Paris in September because of an engine malfunction.

Of 37 A380s currently in service — by Lufthansa, Qantas and Singapore Airlines — 20 are fitted with Trent 900s. The other 17 are equipped with General Electric and United Technologies Corp’s Pratt & Whitney engines.