A CFM International engine for Boeing’s New Mid-market Airplane (NMA) would be a growth version of the Leap series turbofan, suggesting a balance between a derivative and a clean-sheet design, says GE Aviation chief executive David Joyce.

“It will be bigger,” Joyce told a JP Morgan investment conference on 14 March. “It’s advancing [on the Leap technology] not a full generation but a half-generation.”

CFM was formed in 1974 as a joint venture between GE and Safran to produce the single-rotor CFM56, with GE supplying the hot section and Safran delivering the low-pressure module. The partners extended the relationship a decade ago to produce the dual-rotor Leap engine, plus all propulsion applications between 20,000lb-thrust to 50,000lb-thrust per engine.

The engine that Boeing is seeking to power the NMA is likely to fall somewhere within that thrust range, Joyce says.

“The probability is very, very high this will be a CFM engine,” Joyce says.

In a response to a question, Joyce re-affirmed CFM’s position that a version of the Leap engine for the NMA will not require a fan drive gear system to be competitive. Unlike CFM, Pratt & Whitney and Rolls-Royce have proposed engines for the NMA that include a reduction gear between the fan and the low-pressure turbine.

But Joyce remains open to calls by some airline customers for Boeing to offer the NMA with a choice of two engines.

A dual-engine programme, however, “needs a market large enough to offset expenses”, Joyce says. “We have to sharpen our pencils on the size of the market before we would or wouldn’t” commit to a programme with two engine options.

But GE firmly rejects any proposal to offer the NMA with a choice of three engines. “Three is out of the question,” Joyce says, citing the engine industry’s lessons from the Airbus A330 programme, which was introduced with thee engine options.

As Boeing continues to assess options for the NMA engine, CFM’s focus is on catching up to its commitments on Airbus and Boeing for production for the A320neo and 737 Max families, Joyce says.

Engine deliveries are running six weeks behind schedule for both OEMs, but CFM has a plan to catch up by the third quarter, Joyce says.

CFM plans to deliver more than 1,900 Leap engines next year and more than 200 CFM56 engines, he says.

Source: Cirium Dashboard