Rolls-Royce expects the Trent 7000 engines powering the in-development Airbus A330neo to require modification as a result of the technical issues seen on Trent 1000s.

The Trent 7000 – set to enter service in mid-2018 as the sole engine available for the A330neo – is derived from the Trent 1000, an option on the 787.

Although R-R has been forced to redesign the intermediate-pressure (IP) turbine blade on the Trent 7000 and the latest version of the Trent 1000, the -TEN, due to durability issues, the manufacturer has no concerns about the new part's longevity.

"Neither the Trent 1000-TEN nor the Trent 7000 are affected by the issues we have experienced with [IP] turbine blades within the Trent 1000, which have caused unscheduled shop visits," the engine maker says.

However, the durability issues on Trent 1000s also cover the engines' high-pressure (HP) turbine and IP compressor.

R-R is in the process of preparing redesigned blades for both the HP turbine and IP compressor, a source familiar with the situation tells FlightGlobal.

The Trent 7000's HP turbine blade is slightly different from that on the Trent 1000, and disparities also exist between the two engines' IP compressor blades. But the source confirms that R-R will introduce redesigned HP turbine and IP compressor blades for the Trent 7000, which will need to be retrofitted to in-service engines.

The new blades are scheduled to become available by year-end, and will be installed during "targeted", rather than unscheduled, maintenance events, the source says.

R-R states: "Early Trent 1000-TEN and Trent 7000 engines may benefit from proactive maintenance to embody parts… that weren't available at the point of production."

The engine manufacturer does not anticipate a disruptive modification programme as seen on the Trent 1000, because the pool of Trent 7000s and Trent 1000-TENs is smaller and new blades are being prepared earlier in the engines' lifecycles.

R-R says it is "normal practice at the very start of a new engine programme" that parts are updated to address potential in-service issues.