A missing spacer on an oil pipe in the low-pressure turbine (LPT) of the Rolls-Royce Trent 900 has prompted European regulators to order inspections of all Airbus A380 engines powered by the type.
A low-pressure section seized on a revenue service flight, forcing an A380 to return to the departure airport, according to the airworthiness directive (AD) posted on 6 August by the European Aviation Safety Agency (EASA).
The flight crew had detected vibration from the intermediate-pressure turbine (IPT) and several faults from the low-pressure turbine, and throttled back the engine to idle, says the AD.
An initial investigation showed that a "spherical seat", or spacer, between an oil transfer tube and the end cover of an LPT bearing housing end cover had not been installed, the AD says.
The missing spacer allowed the tube to fracture, which reduced oil flow to the bearings of the LPT and IPT.
If not detected, such a condition "could result in uncontained engine failure", the AD says.
The AD requires airlines to inspect the engine to make sure the spacer for the oil transfer tube is properly installed.