Rolls-Royce has begun informing Boeing 787 operators of an accelerated inspection regime for Trent 1000 TEN engines after checks revealed that a “small population” of the powerplants suffered from earlier than anticipated high-pressure turbine (HPT) blade deterioration, the British engine manufacturer said Wednesday. The company established the accelerated inspection regime in cooperation with the European Aviation Safety Agency (EASA), Rolls-Royce noted, adding that the Cologne, Germany-based body will issue an airworthiness directive in addition to its own service bulletin.

“We sincerely regret the disruption this accelerated inspection regime will cause, and we are doing everything we can to support our customers,” said Rolls-Royce president civil aerospace Chris Cholerton. The inspections will allow the OEM to confirm the health of the Trent 1000 TEN fleet over the next few months and “improve our understanding of the HPT blade deterioration that we have seen in a small number of engines,” he asserted.

Singapore Airlines last week grounded two of its 787-10s after it found premature blade deterioration on some Trent TEN turbofans powering its biggest Dreamliners.

Rolls-Royce said it had inspected Trent 1000 TEN turbofans that had logged a higher frequency of flights at the upper end of their operating range. A “small number” of those engines have needed their HPT blades replaced earlier than scheduled.

“This blade deterioration is a known issue but it is occurring faster than we expected in some engines,” Cholerton conceded. Rolls advised airlines that the HPT blades in the Trent 1000 TEN engines would have a reduced life since their entry into service in November 2017, and engineers started development of an enhanced blade last year. The company has begun testing the enhanced version of the blades, and the OEM expects to start incorporating them into the Trent 1000 TEN fleet in early 2020.

The manufacturer insisted the new inspection regime would not affect its ongoing maintenance programs for the Trent 1000 Package B or Package C engines or on its financial outlook on the in-service cash costs of the Trent 1000s. “Based on our current understanding of the situation and fleet management plan, our guidance for in-service cash costs on the Trent 1000 in 2019 and 2020, as published with our 2018 Full Year Results on 28 February 2019, remains unchanged.”

More than 180 Trent 1000 TEN turbofans have entered service.