GE Aerospace has completed testing of a megawatt-class hybrid electric engine system developed through NASA’s Electrified Powertrain Flight Demonstration (EPFD) project, paving the way for flight tests.
The ground test was the company’s first to validate the full integrated system, including GE Aerospace-developed motor/generators, power converters and inverters, controllers, Dowty propellers, Avio Aero gearboxes, and a CT7 engine. BAE Systems provided the batteries used and Boeing subsidiary Aurora Flight Sciences supplied the complete nacelle.
“Step by step, we’re proving hybrid electric engine technology for next-generation commercial aircraft,” said Arjan Hegeman, vice president for future of flight at GE Aerospace. “This latest ground test of a complete hybrid electric powertrain positions GE Aerospace to have the technologies ready to meet customer needs for greater durability, efficiency and range in future propulsion systems.”
Throughout the test campaign at Peebles Test Operation in Ohio, teams simulated various flight phases such as taxi, take-off, climb and cruise. The electric powertrain helped successfully power the propeller and generated power to the battery. Flightworthy components that meet higher safety and reliability requirements than typical test hardware were used as part of GE Aerospace’s efforts to mature a commercial-grade hybrid electric engine system.
This milestone follows more than a decade of testing and maturing individual components and modules.
“The ground test is a major turning point in our understanding of hybrid electric powertrains for aviation and a fundamental building block for the future,” Mr Hegeman said.
A hybrid electric engine system combines an electric powertrain with a traditional gas turbine to optimise power management during different phases of operation. Hybrid electric systems are highly compatible with different fuel types and advanced aircraft engine architectures like Open Fan.
GE Aerospace has leveraged several NASA projects to mature technologies for more electric aircraft engines through the CFM International RISE program.
Unveiled in 2021, the RISE program is one of the aviation industry’s most comprehensive technology demonstrators with more than 350 tests and more than 3,000 endurance cycles completed to date, including tests on Open Fan, compact core, hybrid electric systems and other technologies. The RISE program prioritises safety, durability and efficiency, targeting more than 20% better fuel burn compared to commercial engines in service today.
CFM RISE program technologies are maturing toward ground and flight tests this decade with work underway on aircraft and engine integration in collaboration with partners.
GE Aerospace was first awarded the NASA EPFD contract in 2021 to demonstrate flight readiness of hybrid electric technologies for single-aisle aircraft.
Several key milestones have been achieved over the last decade for hybrid electric technology development:
2016: an electric motor-driven propeller ground test
2022: The world’s first test of a megawatt-class and multi-kilovolt hybrid electric propulsion system in altitude conditions up to 45,000 feet at the NASA Electric Aircraft Testbed facility that simulated single-aisle commercial flight
2025: Successfully demonstrating a narrowbody hybrid electric configuration with power transfer and injection in a modified high-bypass turbofan engine – no energy storage required – through the NASA HyTEC project