Airbus A330neo operators have been included in a new European directive ordering inspections of intermediate pressure compressor shaft assemblies on Rolls-Royce Trent engines for the Boeing 787.
The directive follows the discovery cracks in the front air seal of the shaft assembly during stripping of a flight-test powerplant.
Inspection of other in-shop engines revealed two other instances of cracked seals, says the European Union Aviation Safety Agency.
EASA states that the condition could potentially lead to intermediate pressure compressor shaft failure and in-flight shutdown.
It is ordering repetitive on-wing inspection of an area between the rearmost seal fin of the assembly's front air seal and the compressor's stage one disc.
The timeline for initial checks is staggered with the strictest criteria – for parts over 1,000 cycles – requiring the first inspection within 25 cycles or 30 days. Inspections need to be repeated at 200-cycle intervals.
If cracks are detected, the engine must be removed from service to undertake corrective measures developed by Rolls-Royce.
EASA's directive applies to the Trent 1000 engine, which is fitted to the 787, but also includes the derivative Trent 7000 which is installed on the A330neo. It is the first such directive to be issued by the agency for the Trent 7000.