NASA and GE Aerospace announced a significant milestone for the aviation sector after successfully completing the flight demonstration of a megawatt-class hybrid-electric propulsion system. This technology has the potential to drive the development of next-generation aircraft characterized by greater efficiency and lower fuel consumption.
The engine was integrated into a Saab 340B aircraft and made its first public appearance during the Farnborough International Air Show in the United Kingdom. Before this event, the system had already set two important records: it became the first hybrid-electric powered aircraft to fly above 30,000 feet—the operational range of commercial passenger planes—and recorded the longest flight in its operating mode, exceeding two hours in the air.
This hybrid-electric system combines electric motors, a gas turbine, and energy storage capacity into a single unit. Its purpose is to prove that it is feasible to move regional jet-sized aircraft, reducing operational costs and fuel expenditure without compromising performance. NASA indicates that the lessons learned from this project will be applied to future hybrid systems for commercial aviation, aiming to reduce airline expenses.
In the tested configuration, the right side of the Saab 340B was adapted to accommodate the hybrid-electric system within an inverted nacelle, a choice made to optimize component ventilation. The technical assembly includes motor-generators, inverters, controllers, Avio Aero gearboxes, Dowty propellers, Unison heat exchangers, torque sensors, and a CT7 engine developed by GE Aerospace. Batteries were supplied by BAE Systems, and the complete nacelle was developed by Aurora Flight Sciences, a Boeing subsidiary.
The pioneering flights took place in the United States, piloted by members of GE Aerospace and BETA Technologies. Subsequently, pilots from BETA transported the aircraft to the United Kingdom for the Farnborough Air Show, where the hybrid-electric system was operated through all phases of the journey. H. Lawrence Culp Jr., President and CEO of GE Aerospace, classified this achievement as a historic moment for the industry, thanking NASA, BETA Technologies, and Boeing for accelerating the technology.
This initiative is part of NASA's Electrified Powertrain Flight Demonstration (EPFD) project, building upon years of initial EPFD studies and currently, the Subsonic Vehicle Technologies and Tools project. Hundreds of researchers from various NASA centers worked in partnership with GE Aerospace and other companies. BETA Technologies acted as the systems integrator, while Boeing contributed via Aurora Flight Sciences.
Kyle Clark, founder and CEO of BETA Technologies, emphasized that the tests brought crucial gains for future applications, creating a flying laboratory to guide subsequent hybrid projects. Graham Drozeski, Director of Technology at Aurora Flight Sciences, mentioned that the project enabled, for the first time, the integration of a high-voltage electrified propulsion system onto an aircraft operating at commercial altitudes, marking a significant advance.
NASA considers the success of the tests to represent the peak of more than fifteen years of research focused on developing hybrid systems for large aircraft. While smaller drones and electric aircraft are becoming popular, adapting this technology to passenger and cargo jets has always been a considerable challenge due to the vast energy demand. Initially, over a decade ago, the idea of using electric motors merely as a power supplement seemed distant.
For about seven years, the agency conducted preliminary investigations with partners to map technological barriers and commercial viability. Researchers focused on overcoming limitations related to power generation, thermal control, battery technology, and integration between engines, the electrical system, and the aircraft. Through the EPFD program, NASA and GE Aerospace also managed to create lighter and more efficient components, drastically reducing the size of several parts.
Several space agency facilities were used in the tests. In 2022, GE Aerospace evaluated an integrated version of the propulsion system in the Electric Aircraft Testbed, located at NASA's Neil A. Armstrong facility in Sandusky, Ohio, USA. This center simulated flight conditions at altitudes up to 45,000 feet, similar to those used by single-aisle commercial aircraft. After this phase, electric motors, power converters, propellers, and a commercial GE Aerospace engine were added, followed by ground tests and finally, experimental flights.
Ralph Jansen, aerospace engineer at NASA's Glenn Research Center, described the moment as the conclusion of extensive work, emphasizing the impact it will have on reducing energy consumption and benefiting American companies and the public. He stressed that the project originated from an improbable vision but was turned into reality through research and development. Jansen expressed great emotion upon seeing the flight, noting that the operation was as natural as that of a common aircraft.
GE Aerospace assures that hybrid-electric technology can be implemented in future engine architectures, including advanced concepts such as Open Fan and compatibility with different types of fuels. During the tests, the electric component not only assisted in driving the propeller but also provided energy to recharge the batteries. The company points out that this development integrates the evolution of the CFM RISE program, initiated in 2021, which covers about 500 test campaigns and over three thousand endurance cycles, involving technologies such as Open Fan engines and hybrid-electric systems.
Mohamed Ali, President and CEO of GE Aerospace's Commercial Engines and Services division, concluded that the results prove the technology's potential for the next generation of aircraft, demonstrating advanced capabilities to customers and the industry.
To prevent the experience of flying in an air taxi from being unpleasant and deterring potential customers, NASA is investigating methods to make these journeys smoother and more comfortable.
The space agency used virtual reality simulators to understand how different aircraft movements impact passenger perception and, consequently, their willingness to adopt this new mode of transport. The tests were conducted at the Armstrong Flight Research Center, located in Edwards, California.
NASA employees participated in virtual flights using a motion simulator integrated with virtual reality. This equipment was specifically developed to replicate the conditions that future vertical takeoff and landing aircraft may encounter. During the simulations, volunteers traveled an imaginary route between San Francisco and Alcatraz Island, experiencing various levels of lateral inclination, rapid acceleration, ascent, and descent.
Each volunteer rated the flight experience on a five-point scale, detailing which situations caused discomfort. Variations in reactions were observed: some individuals remained calm even when facing more vigorous movements, while others expressed discomfort with minimal variations.
The collected responses helped researchers develop models that establish a correlation between aircraft behavior and the level of comfort felt by occupants. The goal is to provide crucial data so that manufacturers and operators can optimize both their vehicles and piloting procedures.
Among the central aspects analyzed by the agency are abrupt movements during turns, ascents, and descents; the effect of wind gusts and landings on the passengers' experience; the link between movement intensity and the probability of taking new flights; and defining acceptable comfort limits for air taxi users.
Curtis Hanson, a senior researcher at NASA Armstrong responsible for this study, clarified that the research aims to determine these limits before the service is made available to the public. He stated: 'We can start making predictions about how air taxis should fly so that most passengers find the experience pleasant and want to travel again, which will benefit the public and the industry.'
In addition to the current tests, NASA compared the findings with previous studies on air travel quality. The analysis revealed that contemporary passengers show lower tolerance for uncomfortable movements compared to travelers fifty years ago. This disparity could significantly influence the acceptance of air taxis. Even if technology enables fast urban travel, the quality of the in-cabin experience will be a decisive factor for repeat use of the service.
This study is part of NASA's advanced aerial mobility research, constituting a long-term effort focused on how the human body responds to aircraft movements. The ultimate goal is to contribute to the creation of a new generation of urban flights that is not only technically feasible but also enjoyable for those on board.
