CFM confirms initial LEAP-1A and LEAP-1B assembly allocation

In his weekly Talking Point, Chris Kjelgaard gives an exclusive update on CFM's LEAP engine programme.

In his weekly Talking Point, Chris Kjelgaard gives an exclusive update on CFM's LEAP engine programme.

Gareth Richards, joint LEAP programme director at GE Aviation has revealed the joint venture’s initial plans to allocate final assembly of LEAP-1A engines for Airbus A320neo-family aircraft, LEAP-1B engines for Boeing 737 MAX jets and LEAP-1C engines for Comac C919s.

Speaking to MRO Network News this week, Richards (whose counterpart is employed by Snecma, GE’s joint-venture partner in CFM International), says CFM will perform final assembly of all of the 1,000-plus LEAP-1C production engines required to power the 517 Comac C919s which Chinese carriers have ordered to date at Snecma facilities in Villaroche, France.

In addition, Snecma will assemble all LEAP-1A engines and a sizeable number of LEAP-1B engines. Meanwhile, GE Aviation will concentrate on LEAP-1B assembly for the 737 MAX family. Meanwhile, GE Aviation will concentrate on LEAP-1B assembly for the 737 MAX family.

The reasons for CFM’s allocation of production in this manner are logical when one considers the hypothetical annual production number of 1,500 LEAP-1B and LEAP-1A engines that Richards uses to illustrate CFM’s LEAP assembly-allocation decisions.

Richards argues that the LEAP-1A should win about a 50 per cent market share as one of two engine types (along with the Pratt & Whitney PW1100G-JM) available to power the A320neo family.

(In fact, among A320neo-family customers announcing their engine decisions to date, the LEAP-1A has won a market share of slightly over 50 per cent, but some large customers haven’t announced their engine-selection decisions yet.)

However, all Boeing 737 MAX aircraft will be powered by LEAP-1Bs.

If one argues that the A320neo and the 737 MAX families will each account for approximately 50 per cent of the global market for aircraft their size, then this suggests that roughly twice as many LEAP-1Bs need to be manufactured annually as LEAP-1As.

So Richards’ hypothetical annual-production total of 1,500 LEAP-1Bs and LEAP-1As would consist of roughly 1,000 LEAP-1Bs and 500 LEAP-1As.

However, Richard notes that, for the CFM International 50-50 joint venture, “Our desire for the partnership is to make half of the engines each.”

Over the past four decades the CFM partnership has operated by having Safran subsidiary Snecma produce all CFM engines’ fans, fan cases, accessory gearboxes and low-pressure (LP) modules. GE Aviation produces all CFM engines’ core modules.

However, GE Aviation and Snecma each assemble 50 per cent of the CFM engines produced. This means every LP module has to be shipped by Snecma and core module by GE Aviation to the relevant GE Aviation final assembly line in the USA or Snecma assembly line in France.

For LEAP engines, this arrangement will make for a lot of transatlantic shipping of engine modules.

It also means production engines will be shipped from Snecma’s assembly lines in France to four Airbus final assembly lines (in Toulouse, Hamburg, Tianjin and Mobile, Alabama) and from Snecma’s final assembly lines in France and GE Aviation’s lines in the USA to Boeing’s 737 assembly lines at Renton in Washington state.

Richards’ hypothetical annual 1,500-LEAP number actually is rather low. In fact, according to CFM spokeswoman Jamie Jewell, CFM plans to produce nearly 2,000 LEAP engines of all three versions annually by 2020.

This target represents by far the largest-scale and fastest ramp-up of production ever for any commercial-aircraft jet engine, because this year CFM will deliver only a relative handful of production LEAP engines.

Nevertheless, Richard’s 1,500 number is convenient as a way of illustrating LEAP-assembly allocation because it leaves out for now  the detail of LEAP-1C assembly.

Also, because it disregards potential sales of the Comac C919, the Irkut MS-21 and a possible future Bombardier CS500, the number provides a rough guide to the relative production shares for the LEAP-1A and LEAP-1B.

If, say, CFM International needs to make 500 LEAP-1A engines annually – because the LEAP-1A is powering 50 per cent of the A320neo-family jets delivered – and 1,000 LEAP-1B engines (because it is powering all 737 MAXs delivered), then a logical equal split of assembly would see GE assembling 750 LEAP-1Bs and Snecma 500 LEAP-1As and 250 LEAP-1Bs.

Again, these numbers are purely hypothetical, but the two partners have agreed to this type of assembly-split for initial LEAP-1A and LEAP-1B production.

Richards says, however, “We may choose to change that at any day. Both partners are approved to build [any version of the engine] and the mix is not fixed. The system is so refined that aircraft manufacturers can’t tell any difference between who assembled the engines.”

Each LEAP-1C is shipped from Snecma’s two LEAP lines at Villaroche to Comac’s plant in Shanghai.

There it is integrated with the nacelle – made by Nexcelle, a joint venture between GE Aviation subsidiary Middle River Aircraft Systems and Safran subsidiary Aircelle – to form the integrated propulsion unit which CFM is contracted to deliver to Comac. (Airbus and Boeing are supplying their own engine nacelles for their LEAP-powered aircraft.)

“We have our own dedicated area at the factory in China – a ‘CFM Zone’ – where we can build up the engine and nacelle and integrate it,” says Richards.

So it seems not beyond the bounds of possibility that one day CFM might decide to assemble LEAP-1Cs on a line in Shanghai.

TAGS: Airframes
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