CFM Presses Ahead With New Technology Tests And Leap Fixes

PARIS–Aero-engine joint venture CFM International has completed over 100 tests toward its RISE future engine program, which it is managing in parallel with a huge ramp-up in Leap engine production.

The RISE program was launched in 2021, with the aim of delivering a 20% improvement in efficiency and CO2 emissions. The technology program, which includes an open-fan architecture engine, is not expected to enter service until the mid-2030s, but GE Aerospace VP engineering Mohamed Ali said over 100 tests have already been completed. 

“Sometimes we are running 20-25 tests in parallel, at the same time,” Ali said, speaking at a pre-Paris Air Show briefing. “We are on track for the ground-test demo and the flight-test demo by the middle of the decade. We are quite pleased and encouraged by the results that we are seeing so far.”

CFM is a joint venture between GE and Safran Aircraft Engines.

Two historic issues with open-rotor architecture are noise and blade containment. CFM is working closely with the airframers on both issues and Ali said some early tests with Airbus indicate that the RISE engine will be quieter than today’s Leap engines. Turning to blade containment, he noted that the RISE fan blades will be made of composite materials, with a slower rate of rotation, creating “much lower” energy behind the blade, but containment is a topic being discussed with regulators.

Hybrid-electric propulsion also forms part of the RISE program. Ali said Boeing has procured a Saab 340 that will be used as a hybrid-electric demonstrator with NASA by the middle of this decade.

Switching to the present day, CFM has seen strong demand in recent months, logging large orders from Air India and Ryanair, and building its backlog to over 10,000 engines on firm order. 

“We are ramping up like we have never done before,” CFM president and CEO Gaël Méheust said. 

When the pandemic took hold, CFM went from over 40 engine deliveries per week down to just five. This created a supply chain “tsunami.” 

Méheust said a year ago there were “a lot of red dots” on CFM’s supply chain radar. This has been tackled by increasing the number of people sitting down with suppliers by 20% and working through the bottlenecks, including financing for raw materials.

“We're really tackling every single possible issue. And, as a result of that, the red dots are becoming greener over time. But we're still not completely where we would like to be,” Méheust said. “Things are definitely improving, but it’ll take time.”

CFM will increase its year-on-year production by 50% this year, reaching 1,700 engines. This is expected to grow to 2,000 in 2024, getting CFM back on track with pre-COVID expectations.

Originally, Leap engines were expected to deliver around 15% efficiency improvement, compared with the CFM56, but in-service feedback from operators has increased this estimate to 15%-20%. 

CFM EVP Karl Sheldon said the engine manufacturer is not planning any major changes to the Leap program, however several fixes are underway to resolve some durability issues. 

One of the items to tackle is core durability, affecting blades and nozzle performance in hot and harsh environments, like the Middle East and Africa. CFM has developed new factory-based dust-testing facilities, which are matching well with in-field performance, and a fix is expected to be rolled out in the latter part of 2024. The change will require a shop visit.

“The goal is to get the core durability to the same state that the CFM56 is today,” Sheldon said. “That’s what this blade and this nozzle will do.”

CFM EVP Jérôme Morhet added that the company is looking for new partners to add to its Leap Open MRO network, with the aim of setting up a network of 20 shops, using partnerships with major maintenance suppliers. So far, CFM has announced six of these agreements.

LEAP engines are the sole engine for the Boeing 737 MAX family and one of the options on the A320neo program, where CFM has a 60% win rate. CFM is no longer producing CFM56 engines, however Morhet said parts will continue to be produced until at least 2040.