The existence of a 2011 request for proposal to GE, Rolls-Royce and Pratt & Whitney has now been officially confirmed, as Rolls and P&W have shared preliminary details of its planned 90,000 to 100,000lb thrust class engines to power Boeing's 777X concept.
General Electric, which is the exclusive engine supplier on the 777-300ER, -200LR and freighter, is offering the GE9X for Boeing's conceptual family.
This morning, Rolls detailed its conceptual engine, which it has dubbed the RB3025, exclusively to FlightBlogger and Flightglobal, which it touts will achieve better than 10% improvement in fuel burn against today's GE90-115B engine that powers the 777-300ER, and 15% better than the 777-200ER's Trent 800.
Rated at 99,500lbs with a 337cm (132.5in) fan for the baseline 407-seat 777-9X, giving the RB3025 a bypass ratio of 12:1.
The engine-maker says the current concept provides a low specific thrust and "excellent" propulsive efficiency, along with a 62:1 overall pressure ratio, which, if achieved, would be the highest OPR achieved in a commercial turbofan engine.
The engine builds off of the Trent 1000 and XWB engines, but Nuttall says the RB3025 is derived around its Advanced3 environmentally friendly engine (EFE) technology development programme, which includes a Trent 1000-derived core, lean-burn combustor, composite fan and advanced materials in the high pressure elements of the core.
Additionally, Pratt & Whitney also confirmed it, too, is offering a geared 100,000lb thrust class engine for the 777X in response to Boeing's information request:
Citing an excess of 6,000h and 80,000 cycles on its fan drive gear system (FDGS), P&W says its testing has "validated our analytical prediction that this engine architecture would be suitable to thrusts up to 100,000 pounds."
As the engine-maker "looks ahead to powering future wide-body applications" it plans to "scale the Geared Turbofan architecture to the required thrust levels".
While GE has not confirmed the details of its GE9X offering, the 777's incumbent has begun to begun to firm its own conceptual specifications to power the 777X, say those directly familiar with the engine-maker's planning.
Compared to the 115,000lb-thrust GE90-115B that powers the 777-300ER, the lower thrust 99,500lb and derated-88,000lb GE9X for the 777-9X and -8X, respectively, are enabled by the larger, higher-lift and comparatively lighter composite wing. The eCore-inspired engine would also feature a GEnx-style composite fan casing and third-generation Twin Annular Premixing Swirler (TAPS) Combustor, dubbed TAPS III, say those familiar with the engine maker's planning.The 325cm (128in) diameter GE9X engine is believed to tout an approximately 10:1 bypass ratio, 60:1 overall pressure ratio and 27:1 high pressure compressor ratio, compared to the 42:1 and 23:1 pressure ratios, respectively, on today's GE90-115B.
Boeing says it's far too soon to say if one or more engine choices would be available on the 777X, as it has yet to be officially launched, but it appears that both Rolls-Royce and Pratt & Whitney are readying for a significant battle with GE to power the next-generation 777.