Rolls-Royce is formally accusing rival Pratt & Whitney of infringing patents regarding the design of blades in the fan stages of its PW1000G geared turbofan and Engine Alliance GP7200 powerplants.
Engine Alliance - a tie-up between P&W and General Electric - builds the GP7200 for the Airbus A380, competing with the Rolls-Royce Trent 900. P&W's PW1000G is an all-new development, based on geared-turbofan technology, aimed at the Bombardier CSeries.
Rolls-Royce says it has filed a case against P&W parent United Technologies with the Eastern District of Virginia federal court, claiming infringement of its patent for swept fan blades.
It states that it is seeking "damages and injunctions" and expects a jury to hear the case in the first half of next year.
Rolls-Royce says the dispute has smouldered for several years, claiming that it was started by United Technologies which tried, unsuccessfully, to remove the UK firm's patent for swept fan blades.
It adds that its complaint alleges that "a number" of other civil aero engines manufactured by United Technologies also infringe the patent.
Neither United Technologies nor P&W has immediately responded to the filing.