Open Fan Advances Toward Flight Test Demonstration This Decade

• Key design reviews completed
• Earliest ever durability testing for new technology development
• Mid-decade hybrid electric ground tests meet program commitments

FARNBOROUGH, England - 18 July 2026 - CFM International announced today, ahead of the Farnborough International Airshow, new design and test milestones reached for the RISE program, a suite of technologies in development for next-generation aircraft propulsion.

In the five years since CFM unveiled the RISE program, approximately 500 test campaigns have been conducted on advanced engine architectures such as Open Fan, compact core, and hybrid electric systems. Recently completed reviews for key Open Fan and compact core modules have confirmed design concepts.

Technologies are being matured toward ground and flight tests this decade.

Gaël Méheust, president & CEO of CFM International said, "Our engineers are doing a fantastic job maturing the most advanced technologies the industry has seen to date while balancing this innovation with the experience of more than 1.4 billion flight hours in the single-aisle market. As CFM, we have a unique understanding of our customers day-to-day operations and the important role that durability and maintainability play, in addition to efficiency."

Advanced Open Fan testing

Mechanical and material tests are underway on Open Fan blades and Outlet Guide Vanes (OGVs), including impact, ingestion, fatigue, endurance, load, icing and vibration response. First results from test campaigns including wind tunnel facilities have demonstrated that aeroacoustics performance has exceeded technology maturation objectives.

Open Fan is a jet engine design that removes the traditional casing, allowing for a larger fan size with less drag to improve durability and fuel efficiency. OGVs are the second stage or row of airfoils behind the fan to help direct air flow, key to how the Open Fan design can achieve the same speeds and altitudes as turbofan engines flying today.

With Preliminary Design Reviews of the Open Fan and OGV airfoils complete, CFM is leveraging both composite turbofan blade technology experience and turboprop expertise in blade retention, variable pitch, and durable propeller structures. Unique supercomputing capabilities are optimizing designs for acoustics and aerodynamics.

"While Open Fan is a new architecture, the technologies inside have been proven over decades of innovation," said Arjan Hegeman, vice president of future of flight engineering for GE Aerospace, one of CFM's parent companies. "We're testing real, full-size Open Fan hardware, showing real progress and a renewed ambition from CFM to advance the RISE program and deliver the vital technology step-changes for durability and efficiency to power the future of air travel."

The first high-speed low-pressure turbine, part of the fan system, was also recently tested for more than 1,000 hours. Teams validated the LPT's aerodynamic design as well as its aerothermal performance.

Dust ingestion tests underway

Open Fan architecture has inherent durability advantages compared to a next-generation conventional engine design, including cooler core temperatures and adaptive cycle technology for more effective particle extraction. Durability testing is being conducted earlier than ever in new technology development to improve hardware designs, which is important for customer operations. Teams also completed the compact core systems Preliminary Design Review.

More than 2,000 cycles of dust ingestion tests have been completed to evaluate next-generation high-pressure turbine (HPT) airfoil technologies in an engine core. A second dust ingestion test of RISE program HPT technologies inserted in a more product-representative LEAP-1B engine is also improving understanding of how next-generation technologies could benefit the fleet today.

Hybrid electric ground tests

Both CFM parent companies are actively ground testing hybrid electric systems through the RISE program.

Safran Aircraft Engines is making significant progress in hybrid-electric propulsion. The company launched PHILEAS, a ground testing campaign at its Istres site in France. PHILEAS is a full-scale engine demonstrator equipped with two electric machines designed for the next generation of short- and medium-range aircraft engines.

GE Aerospace completed two hybrid electric engine ground tests within the last year, demonstrating the feasibility of more electric aviation with and without energy storage.

"The RISE program is gaining strong momentum, moving from concept to reality. More than 2,000 CFM engineers are advancing the technologies that will enable the next generation of propulsion. We are validating every key building block for Open Fan, supported by extensive testing capabilities. As we prepare to test a full-scale front module of the Open Fan in our new 8-meter test cell at Villaroche, we are building on decades of expertise, including for composite fan blades, to shape the future of aviation," said Pierre Cottenceau, Engineering and R&T EVP, Safran Aircraft Engines.

About the RISE program

Unveiled in 2021, the RISE program is one of the aviation industry's most comprehensive technology demonstrators with approximately 500 test campaigns and more than 3,000 endurance cycles completed to date, including tests on advanced engine architectures like Open Fan, compact core and hybrid electric systems. The RISE program prioritizes safety, durability and efficiency, targeting more than 20% better fuel burn compared to commercial engines in service today.

*Revolutionary Innovation for Sustainable Engines (RISE) is a technology demonstration program of CFM International, a 50-50 joint company between GE Aerospace and Safran Aircraft Engines. It is not a product for sale.