Rolls-Royce has identified another durability issue in its Trent 1000 series engines, this time involving the intermediate pressure compressor in the Package B version. The variant has flown in service on Boeing 787s since 2012 and consists of 166 engines. The engine company said it has agreed with regulatory authorities to carry out a one-time inspection of the Package B fleet to “further inform” its understanding of the problem.

Rolls added that it expects the European Aviation Safety Agency to issue an airworthiness directive in “the coming days,” resulting in “limited impact” on customer operations.

“We are committed to eliminating this intermediate pressure compressor [IPC] durability issue from the Trent 1000 fleet and we have already successfully run a redesigned Package C IPC in a development engine,” said Rolls-Royce in a June 11 statement. “As a precautionary measure we have also launched a redesign of the relevant part in the Package B engine as well as in the Trent 1000 Ten engine, where, although currently a young fleet, we have not seen any examples of reduced IPC durability.”

In April Rolls-Royce advised operators that its Trent 1000 Package C engine would require more inspections than previously planned to address premature wear of compressor blades, a problem that first came to light in 2016. The company reported that it had delivered 380 Package C engines, powering some 25 percent of all Boeing 787s in service. The majority passed inspection and therefore continues to fly, according to a Rolls-Royce spokesman who declined to enumerate “majority.”

The UK aero-engine company said in late May that it would accelerate the development of the permanent fix to the IPC rotor issue on Package C engines and that it had installed a revised compressor blade in an engine scheduled for testing this month. “We aim to have first parts available for engine overhaul in late 2018, rather than 2019 as originally planned,” Rolls-Royce civil aerospace president Chris Cholerton said.

Rolls also said it had begun speeding the development of the new blade and a dedicated facility in Derby to build engines on which it will test it. It also developed new on-wing inspection techniques to support airlines in meeting the requirements of the airworthiness directives “as quickly and efficiently as possible,” it said. 

Cholerton admitted Rolls-Royce expects the number of aircraft affected “to rise in the short term, as the deadline for the completion of initial inspections approaches,” though it remains tight-lipped on the actual numbers. “We are not confirming number of aircraft grounded,” the spokesman said.