Rolls-Royce is joining forces with Pratt & Whitney to apply geared turbofan (GTF) technology on next-generation engines, but the core of the UK-based manufacturer's long-term development strategy remains intact, a senior executive told Flightglobal.
Work will continue on R-R's three next-generation engine concepts - the two-spool Advance2 for the mid-size aircraft sector, the three-spool Advance3 for large aircraft and the open rotor engine, said Mark King, president of R-R civil aerospace.
The GTF technology, which P&W has pioneered with the PW1000 engine series, now becomes a key piece in R-R's development strategy.
Next generation engines will demand ultra-high bypass ratios and large fan diameters, King said. As fans increase in size, it becomes more efficient to slow the rotation of the fan in relation to the low-pressure turbine spool. Indeed, R-R's strategy may come to depend on gear technology for the Advance2 and open rotor engines to achieve their efficiency goals.
"I don't see this [joint venture] as a major change of strategy," King said. "I think I see it as a natural extension of our strategy and an elegant solution."
But relations between the two engine rivals on P&W's GTF strategy have not always been so cozy.
In May, R-R lost a lawsuit accusing P&W of stealing fan blade technology for the PW1000 series. R-R executives also have not been shy about criticising the strategy embraced by P&W, Airbus and - more recently - Boeing to re-engine the narrowbody fleet rather than shift to a clean-sheet design.
King said that R-R's criticisms were focused on a particular application - not against the value of the GTF technology.
"You've not heard me discounting the geared turbofan strategy," King said. "I have always said I like our partnership with Pratt & Whitney, and I have always said I would like to find ways to work with Pratt & Whitney in the future."
The two members of the joint venture have not decided on the division of manufacturing roles for next generation engines, King said.
Separately, R-R and P&W have agreed to restructure the International Aero Engines consortium, which makes the V2500 turbofan for the Airbus A320. P&W will pay R-R $1.5 billion for its equity stake and make payments to R-R for 15 years based on the number of hours flown by the installed base.
That agreement means P&W is the majority owner of V2500 engines for A320 and PW1100G for the A320neo.
It is an arrangement that "provides a common interface across the new members of the A320 family", King said.