Rolls-Royce said its timetable to fix problems found in the TEN version of the Trent 1000 engine will be delayed after evaluations revealed that proposed modifications would not deliver a “sufficient level” of enhanced durability.

The development of a new high-pressure turbine (HPT) blade for the TEN-derivative of the Boeing 787 engine is now unlikely to be ready before the first half of 2021, the company said in a financial update on Nov. 7.

The issue, one of nine that has affected all three versions of Trent 1000 family, adds to the growing financial and reputational pain experienced by the British aero-engine OEM.

A financial review of the Trent 1000 program revealed a £2.4 billion ($3.08 billion) cost associated with fixing the problems, although this does not include an additional £1.4 billion charge in 2019 as a result of customer shop and remediation shop visits, as well as from expected contract losses in the coming years.

The problems have already caused extensive disruption for airlines, leading to the grounding of aircraft and forcing them to find additional capacity.

Of the nine problems found in the Trent 1000 Package B, C and TEN models, eight have been designed and seven have been certified and are being incorporated into worldwide fleet.

Issues with the redesigned TEN-model HPT blade emerged following a “detailed technical evaluation” of the proposed redesign.

“Although we regret that the blade will not be ready when we had originally planned, our understanding of the technical issues has significantly improved,” Rolls-Royce CEO Warren East said.

He said the company had “reset” its financial and operational expectations for the engine and was now able to provide a “prudent durability estimate.”

“This will give our customers and ourselves a higher degree of certainty as we plan for the servicing of the fleet over the coming years,” East said.

The issues with the Trent 1000 TEN also have implications for the Trent 7000 powering the Airbus A330neo. Rolls-Royce had planned to introduce the HPT blade from the TEN-model onto the Trent 7000 once it was available, but the development delays mean a later introduction to the Trent 7000. The company said it has been able to plan maintenance capacity and spare engine provision to safeguard against customer disruption.

Rolls-Royce said it is taking additional actions to ensure it meets its target of bringing the number of aircraft impacted by the Trent 1000 issues down to single digits.

However, this target has moved to the right from the end of 2019, as hinted by East in the company’s half-year report in August. It now expects to achieve that target by the second quarter of 2020.

Rolls said it plans to increase its stock of spare engines, reducing the time to return aircraft to flight, and will accelerate the growth of its MRO network to deliver a “near-term increase” in capacity for the Trent 1000. The company’s sites at Dahlewitz, Germany, and Montreal, Canada, will become service hubs to support Trent 1000 overhauls. The company has also secured an additional test bed in Dallas/Fort Worth for Trent 1000 testing. There will also be expansion at both the company’s Derby and Heathrow sites in the UK.

“This investment marks a step-change in our MRO expansion plans and will assist us over the longer term in meeting the servicing demands of our growing installed base,” company officials said.

There will also be additional investments in the engineering team resolving the Trent 1000 issues. A new bespoke facility has been established in Derby, also dedicated to testing, which is now fully operational, the company said.

East said he hopes the steps would reduce disruption to its airline customers and “give them the certainty that they need.”

Tony Osborne, tony.osborne@aviationweek.com