Addressing premature blade deterioration of Trent 1000s ranks as Rolls-Royce’s "single most important issue," acknowledges the aero engine company, which professes “deep regret” for the disruption to customer operations and the resulting groundings that cost the UK manufacturer some £430 million (about $540 million) last year.
Dominic Horwood, the company's civil-aerospace chief customer officer, called the "significant" disruption to customers "absolutely unacceptable to them and to us" and stressed the importance of providing support by returning engines to operators. Rolls-Royce added it has become "more responsive in turning engines around" and hopes to see single-digit numbers of aircraft on the ground (AOG) by the end of 2019.
Horwood said the company "respects" Air New Zealand's decision to choose General Electric GEnx powerplants for a new batch of Boeing 787-10s over the incumbent Trent 1000s that power its 787-9 fleet. "They are still an important customer to us,” he remarked. “The way we support customers is how we will be remembered.”
The official went to pains to emphasize that the blade-deterioration resulted from a design issue specific to the Trent 1000 at the "component level" and does not apply to other Trent-family variants. "We haven't seen these issues on earlier models [because it] comes down to detail design of this product," he explained.
Intermediate-pressure turbine issues have resulted from a sulfidation attack at the root of the blade, according to Horwood. Typically, a small "coating" or mark can cause local turbulence of the air and temperature around the blade.
Such situations can result, for example, from the atmosphere in regions where an engine has flown, knowledge of which can help a manufacturer understand how failures happen. Investigation of the issue has accelerated Rolls's understanding, but Horwood stressed a need for early detection. "The question is how to find such issues on the test bench, how to make the engine think it has been operating for years in, [say], Asia," he said.
Rolls-Royce civil aerospace marketing vice-president Richard Goodhead characterized the endeavor as a good example of "contextual awareness"–a key part of the manufacturer's "three Cs" philosophy alongside the need to be "connected" and "comprehending."
Horwood said the manufacturer, which claims good progress in introducing technical fixes, never stops learning. The lessons reside very much in detail design of components and an understanding of what can cause deterioration in service. “Once we have done that, then it is easy to apply on new engines,” he explained. "[This is] not about mistakes, but about applying lessons. [We are] already applying that learning in the UltraFan future-technology program.”