For CFM International, 2015 is a critical year in terms of program execution as the Leap engine family advances towards service entry on three new-generation narrowbody airliners. On May 19, the first example of the Airbus A320neo powered by the Leap 1A made its maiden flight. Both the Leap 1B for Boeing’s 737 Max aircraft and the Leap 1C for Comac’s C919 are being evaluated on a 747 flying test bed operated by GE Aviation, which is partnered with Snecma in the 40-year-old CFM joint venture.

 “This year is all about our ability to deliver on the promises we have made, both in terms of engine development and production,” CFM International president and CEO Jean-Paul Ebanga told AIN in an interview ahead of the Paris Air Show. “We’re convinced that this will be truly disruptive technology.”

CFM is preparing to deliver a total of 11 Leap 1A engines to Airbus for testing on its A320, 321 and 319neo aircraft. Airbus expects to complete certification of the Leap-powered aircraft in mid-2016, with the version powered by the rival Pratt & Whitney PW1100G turbofan due to be approved around the end of 2015.

Next year should also see certification of the Leap 1B engine for Boeing’s three 737 Max twinjets (the -9, -8 and -7 variants), which are due to enter service in 2017. Later this year, CFM expects to deliver the first Leap 1Cs to China’s Comac for the C919. For this program, CFM, with its sibling Nexcelle, is providing a complete integrated powerplant, that also includes a full nacelle, inlet, cowl and thrust reversers.

To date, CFM has logged almost 9,000 Leap engine orders and the company is acutely focused on the need to deliver these on time and according to specification. According to Ebanga, some 28,000 examples of the existing CFM56 turbofans have been delivered to airframers and not one of these has delayed the delivery of an airliner.

According to Ebanga, CFM’s transition to production of the Leap family marks the first time in industry history that a manufacturer will have switched to a new product when the existing product is at its peak rate of production. “The CFM56 production rate has increased year-on-year for the past 10 years,” he pointed out.

The company expects to continue producing CFM56 parts for at least another 30 years, until 2045. It cannot be sure when the transition to an all-Leap production line will be complete since this will effectively be determined by the rate at which Boeing and Airbus continue to produce their respective 737 and A320 families with their original powerplants.

The foundation on which CFM is establishing Leap production is a multi-national supply chain that Ebanga claimed is the most global in the aero-engine industry, and which is currently producing around 1,600 turbofans per year. Most of the existing CFM56 partners are also involved in the Leap program. The main difference is in the new technology parts, such as resin-transfer molder composite fan blades, for which the CFM partners GE and Snecma are setting up new factories, respectively in New Hampshire and France.

“No-one is better equipped than us to deal with this ramp up,” said Ebanga. “Getting to production readiness for Leap has been a five or six year journey.” Running in tandem with the Leap program’s technology ‘tollgates,’ which signify whether the engineering work is progressing in a satisfactory way, CFM also has conducted sequential manufacturing readiness reviews to ensure that production planning is keeping up with development tasks. The Leap manufacturing team based at GE’s Cincinnati, Ohio, headquarters is co-located with the program development team.

According to Ebanga, GE and Snecma have invested more than $800 million to build new factories for Leap, as well as to upgrade existing facilities. “We have already stess-tested the production system to deal with surges [in output] to the highest possible rates and this process has been applied to our internal supply chain as well as to our external suppliers,” he told AIN.

Technology Leadership

“When I joined CFM four years ago, some people in the market were still trying to understand the path we chose with Leap,” said Ebanga. “Four years down the road, the industry got it, finally, not only because we have demonstrated that Leap has met the expectations we had for it but also because there is generally a greater awareness of the new technologies we have used. These include genuine industry-firsts that others have now embraced, such as additive manufacturing, which we were the first to talk about, and carbon fiber composite fan blades, for which we will have the first in commercial service.”

According to Ebanga, CFM is two generations ahead of the rest of the engine industry with carbon composite technology. GE first introduced laminate technology to the GE90 engine in the 1990s and Snecma developed three-dimensional woven materials employed for Leap that represent the second generation of composite technology.

“With additive manufacturing, the question isn’t whether or not we can use it for Leap parts, but how are we going to optimize the technology to produce a high volume of parts,” said Ebanga. “Each Leap engine has 18 or 19 fuel nozzles, and by 2020 we will be building at least 1,900 Leap engines. So at that point no-one else will be producing nozzles on that scale, around 36,000 per year.”

According to Ebanga, Leap customer-support initiatives are being prepared “with the same level of intensity” as the development and manufacturing process. “We have prepared a learning experience for the [airline] customers so that they have the right level of organization and process to deal with the engine after entry into service,” he explained. So far, there are almost 60 Leap customers, compared with the 550 CFM56 operators worldwide. “Most [Leap] operators will do about eight-to-10 flights per day and our goal is to help them to have a flawless entry into service,” he said. o

Leap Testing Set To Climax This Year

The majority of Leap engine certification testing will be complete by the end of 2015, which CFM Leap program manager Gareth Richards described as “our most intense year of testing, ever.” As of last month, there were 33 Leap engines involved in various tests at GE Aviation’s Boeing 747 flying testbed site in Victorville, California, as well as in Peebles, Ohio, and at two Snecma sites in France. By comparison, Richards pointed out that the larger GE90 turbofan development program involved only seven engines.

Richards explained that all three Leap engines have been optimized for their respective aircraft but share a common design philosophy. “So we do apply the lessons learned from all tests when they apply universally,” he told AIN. “For instance, we can use software to tune the way an engine operates through factors such as controlling clearances [between the case and the fans].” Other changes made across the three engines include improvements to the coating systems for the inside of the cases.

Even before the Leap engines take to the air on their respective new airliners, CFM has already tested their full flight envelopes on its own flying testbed. It has also already completed key tests such as bird-strike and blade-out.

CFM uses the flying test bed to validate engine performance, and this process continues while flight-testing the new aircraft themselves. Other important tests include those needed to ensure that the engines will correctly interface with all related systems, such as fuel tanks. Other tests include assessing the engines’s acoustical and emissions performance.

“We’re very confident that we will reach the promised specifications [for factors such as fuel burn], and we’ve made big financial guarantees to back up this commitment,” said Richards. “We could have chosen to go further [in terms of fuel efficiency] by running the engine hotter or at higher pressure, but we chose not to do that, because Leap engines will be used for shorter flights of around one or two hours and so durability and maintenance costs are bigger considerations. We’ve reserved further advances in fuel efficiency for future developments, because Leap is going to be around for 30 years or so.”