RISE (aeronautics)

RISE (aeronautics)
Name	RISE
Type	Open rotor engine technology demonstrator
National origin	United States
Manufacturer	CFM International
First flight	Planned for mid-2020s
Status	Under development
Primary user	Intended for Airbus and Boeing next-generation aircraft
Number built	Prototypes in development
Developed from	CFM56, LEAP
Developed into	Future production engine (RISE*)

RISE (aeronautics). The RISE program, an acronym for **Revolutionary Innovation for Sustainable Engines**, is a major advanced technology demonstrator initiative led by the CFM International joint venture between GE Aerospace and Safran Aircraft Engines. Its primary objective is to develop and validate a suite of breakthrough technologies, most notably an open rotor or unducted fan architecture, aimed at achieving a 20% reduction in fuel consumption and CO2 emissions compared to today's most efficient engines like the LEAP. The program is a cornerstone of the global aviation industry's strategy to meet ambitious environmental goals, including those outlined in the Air Transport Action Group's net-zero roadmap, and is targeted for entry-into-service on next-generation Airbus and Boeing aircraft in the mid-2030s.

Overview

The RISE program was officially launched by CFM International in June 2021 as a direct response to the aviation sector's urgent need for radically improved propulsion efficiency. It represents a multi-billion-dollar investment by the partners, GE Aerospace and Safran Aircraft Engines, to mature technologies considered essential for the next leap in engine performance. The demonstrator is not a complete engine for a specific aircraft but a flying testbed designed to prove core technologies at a relevant scale. Its development is closely watched by major airframers, with both Airbus and Boeing providing input, as the technologies are intended to power their potential future narrowbody successors to aircraft like the Airbus A320neo family and the Boeing 737 MAX. The program's success is considered critical for maintaining CFM International's market leadership against competitors like Pratt & Whitney and Rolls-Royce Holdings.

Development and Design

The design philosophy of RISE centers on an open rotor architecture, which removes the large nacelle casing found on traditional turbofans, exposing the fan blades to the free air stream. This configuration, previously explored in programs like the General Electric GE36 and the McDonnell Douglas MD-94X, allows for a much larger fan diameter and higher bypass ratio, dramatically improving propulsive efficiency. Key enabling technologies include advanced composite fan blades, a compact high-pressure core derived from the CFM RISE program's parent technologies, and innovative pitch change mechanisms for the counter-rotating fan rows. Furthermore, the RISE design is being developed as a "ready-for-sustainable-fuels" platform, fully compatible with 100% Sustainable Aviation Fuel and designed with hybrid-electric capability in mind, allowing for the future integration of an electric motor to drive the fan.

Technical Specifications

While final specifications for a production engine remain undefined, the RISE technology demonstrator is designed to validate components and performance at a thrust class relevant for next-generation single-aisle aircraft. The open rotor design targets a bypass ratio significantly greater than the approximately 11:1 of current-generation LEAP engines. It incorporates a state-of-the-art core aiming for unprecedented thermal efficiency, leveraging advancements from the U.S. Department of Energy and NASA research programs like the HyTEC project. The demonstrator will also test advanced ceramic matrix composites, heat-resistant alloys from GE Aviation's research, and new acoustic treatment technologies to mitigate the noise profile historically associated with open rotor designs, a critical factor for meeting stringent International Civil Aviation Organization noise standards.

Operational History

As of 2024, the RISE program is in a rigorous ground testing phase. Major milestones include the completion of initial fan blade rig tests and the ongoing assembly of core demonstrator components at facilities operated by Safran Aircraft Engines in France and GE Aerospace in Evendale, Ohio. The first full-scale demonstrator engine is scheduled to begin ground tests around 2025, with a flight test campaign on a modified Boeing 747 or similar flying testbed planned for the latter half of the 2020s. This flight test phase, crucial for gathering real-world data on performance, noise, and integration, will be a pivotal moment for the program, informing the final configuration for a certifiable product dubbed RISE*.

Variants

The primary output of the RISE technology program is expected to be a future production engine family, currently referred to as RISE*. This family would be tailored to meet the specific requirements of different airframers and aircraft models, potentially including both open rotor and advanced ducted configurations depending on market and regulatory acceptance. The core technologies developed under RISE may also spawn derivative applications, such as more efficient engines for regional jets or hybrid-electric propulsion systems. Furthermore, lessons learned are feeding into parallel research efforts within the Clean Sky Joint Undertaking in Europe and the NASA Sustainable Flight National Partnership in the United States.

Program Status and Future

The RISE program is on track with its published roadmap, representing one of the most significant near-term bets on a radical engine architecture. Its future hinges on successful technology validation, meeting acoustic and safety certification requirements with regulators like the Federal Aviation Administration and the European Union Aviation Safety Agency, and securing a launch commitment from a major airframer. A decision on launching the RISE* production engine is anticipated around 2028-2030. The program is widely seen as a foundational step toward the aviation industry's 2050 net-zero goals, with its technologies potentially enabling further integration with hydrogen combustion or fuel cell systems being explored by Airbus under the ZEROe initiative.

Category:Aircraft engines Category:CFM International Category:Experimental aircraft engines Category:2020s in aviation