What is CFM RISE? Inside GE and Safran’s open fan engine for net-zero aviation
September 27, 2025
Today’s jet engines are among the most powerful and efficient machines in aviation, combining lightweight materials and advanced design to deliver high performance at relatively low cost. But with the industry under pressure to achieve net-zero emissions, the limits of conventional engine architecture are being tested.
The CFM International Revolutionary Innovation for Sustainable Engines (RISE) programme aims to push those limits. A 50–50 joint venture between GE Aerospace and Safran Aircraft Engines, RISE is developing open fan propulsion technology designed to cut fuel consumption and carbon emissions by 20% compared with today’s engines, with entry into service targeted for the mid-2030s.
Apart from the open fan, the RISE program will offer a range of pioneering technologies, including a compact high-pressure (HP) core, hybrid electric systems, and compatibility with alternate jet fuels. The program has so far completed more than 350 components and module tests through a variety of technology demonstrators.
CFM RISE open fan engine technology
Enhancing propulsive efficiency is key to the success of the RISE program. The progression from single-shaft engines to high-bypass ducted fans is ultimately leading to the open fan concept. Unlike conventional ducted fan engines, the open fan design removes the outer casing, allowing for a much larger fan design.
The increased mass flow rate of air moving through the fan makes the engine highly efficient. The higher bypass ratio (the ratio of the airflow bypassing the engine core to the airflow passing through the core) significantly minimises fuel consumption as well as noise emissions.
Each fan blade is over 1.6 metres in length and designed with advanced 3D Resin Transfer Moulding (RTM) through Safran Composites’ innovation platform. The composite technology, already proven on CFM LEAP fan blades, allows significant weight reduction and improved fuel efficiency.
Compact high-pressure core and hybrid-electric systems
GE Aerospace is developing a compact and durable HP core (compressor, combustor, and turbine) as part of the core demonstrator for the CFM RISE program. In May, the company completed an endurance test campaign on HP turbine airfoil technologies, simulating high-thrust takeoffs and climbs. More than 3,000 cycles of endurance tests validated the durability, reliability, and fuel efficiency of the HPT system.
The vice president of future of flight engineering at GE Aerospace, Arjan Hegeman, stated, “With endurance tests conducted on new high-pressure turbine blade cooling technologies, it shows the CFM RISE program’s early focus on durability and reliability. This is the earliest in new technology development that we’ve done durability tests, incorporating the experience of our commercial aircraft engines flying today.”
Another key objective of the RISE program is airframe integration. In addition to efficient materials and propulsive system efficiency, the engine-wing integration and resulting aerodynamic performance are essential. The installed performance of the advanced architecture will be tested through partnerships with aircraft manufacturers.
Testing milestones for CFM RISE programme
The RISE program aims to demonstrate open fan engine technologies that would lay the foundation for future engines. In 2022, CFM and Airbus jointly launched a flight test demonstrator program that would facilitate testing of the advanced open fan onboard an A380 test platform.
The two companies aim to accelerate the development of the propulsion technology while enhancing airframe integration.
The flight test campaign, anticipated to commence by the end of this decade, will also focus on the engine’s acoustic performance as well as its compatibility with 100% Sustainable Aviation Fuels (SAF).
The open fan architecture is designed to fly at speeds similar to existing commercial aircraft, with greater operational efficiency and lower carbon and noise footprint. As technologies continue to mature, the CFM RISE program will leverage synergies with aviation partners to begin full-scale open fan tests.
