An aircraft powered by a megawatt-class hybrid-electric engine developed in collaboration with NASA and built by GE Aerospace, demonstrated flight of an innovation that can inform new generations of fuel-saving aircraft power systems.

Mounted to a Saab 340B aircraft, the engine flew at Farnborough International Air Show in the United Kingdom. It was the public debut of a system that has in recent months made historic test flights, becoming the first hybrid electric-powered aircraft to fly above 30,000 feet.

“This achievement reflects what NASA does best in aeronautics: we explore bold possibilities, validate them through rigorous research and testing, and work with industry to turn breakthrough ideas into technologies that bring real value for the American people,” said Laurie Grindle, director of the Aeronautics Division within the agency’s Research and Technology Mission Directorate at NASA Headquarters in Washington.

The testing leveraged work done through NASA’s former Electrified Powertrain Flight Demonstration project and the agency’s ongoing Subsonic Vehicle Technologies and Tools project – years of collaborative research that included key testing at NASA test facilities. 

The engine integrates electric motors, a gas turbine, and energy storage capabilities. It was designed to demonstrate the capacity to power an aircraft around the size of a regional-class jet, reducing fuel burn and costs without sacrificing performance. The unit’s technology and designs are expected to be used to help develop future hybrid systems that could lower airline operating costs. 

The demonstration flight came after years of rapid development for the technology. For NASA, it also validates work that stretches back to a time when hybrid aviation propulsion seemed almost beyond the horizon of possibility.

“This is the culmination of more than 15 years of work, and we did that because it’s going to have an impact for aircraft that will help reduce energy use and help U.S. companies and the public,” said Ralph Jansen, aerospace engineer at NASA’s Glenn Research Center in Cleveland. “It’s about having a vision that no one believes can happen and then doing the work to define and execute the research and development needed to make it happen.”  

This accomplishment was possible because of the collaborative effort of hundreds of people working on Electrified Powertrain Flight Demonstration and Subsonic Vehicle Technologies and Tools projects across NASA centers, in conjunction with GE Aerospace and its partner companies.

Hybird-Electric Evolves

In recent years, aviation has seen a boom in small aircraft and drones powered by electrical systems drawing from batteries. But large passenger and cargo planes require complex engines capable of supplying massive amounts of power. So more than a decade ago when NASA began contemplating hybrid systems, just the possibility of using electric motors to supplement some energy was a daunting engineering challenge. 

NASA spent about seven years performing preliminary research, working with small businesses and other partners to consider technological obstacles and the potential commercial viability of hybrid systems. During that time, the agency addressed several barriers to implementation including the power, thermal, and battery technology, and the integration of the power system, engine, and aircraft.

Through the agency’s Electrified Powertrain Flight Demonstration award, GE Aerospace and NASA worked with researchers to develop lighter and more efficient power systems and shrink key components – sometimes dramatically. 

NASA and GE Aerospace also leveraged agency facilities and resources to further their research. In 2022, GE Aerospace tested an integrated version of its propulsion system at NASA’s Electric Aircraft Testbed at the agency’s Neil A. Armstrong Test Facility in Sandusky, Ohio. Testing allowed the system to operate in conditions simulating 45,000 feet in altitude, the range in which commercial single-aisle aircraft fly. 

The team added components, including electric motors, power converters, propellers, and a GE Aerospace commercial engine, followed by more ground tests and eventual flight tests. For the researchers who’d spent years on the concept, seeing the engine powering an aircraft in flight was a major step in a long journey.

“I’ve got to say, I was pretty touched seeing it fly. It was just awesome,” Jansen said.  “It’s just like a regular plane, which is probably the best thing of all.”

NASA’s current support for this research is through the Aeronautics Division of its Research and Technology Mission Directorate.

NASA researchers recently put a new wing design, appearing long and thin with a lightweight structural design, through a series of grueling tests to find its structural limits. What they found left them encouraged about the wing’s potential, even when they pushed it past its intended limits.

The 15-foot Structural Wing Experiment Evaluating Truss-bracing (SWEET-15) test article is part of NASA’s research to develop future ultra-efficient aircraft. The design incorporates a long wing supported by an aerodynamic strut, based on NASA’s earlier Transonic Truss‑Braced Wing concept.

The research team is working to understand whether SWEET-15’s design and its new lightweight structural designs could help commercial airliners save fuel. But first, they need to understand how it behaves under the kinds of force wings experience in flight.

The SWEET-15 design originated with combining five different advanced composite manufacturing and assembly technologies that enabled the novel structural design. The 15-foot-long test article was then designed and fabricated at NASA’s Langley Research Center in Hampton, Virginia, before traveling to NASA’s Armstrong Flight Research Center in Edwards, California, for testing.

Over several months, NASA engineers intentionally bent the test wing in the Flight Loads Laboratory at NASA Armstrong. Numerous strain and load sensors, including fiber-optic strain sensors, were placed throughout the structure to track how the wing responded as forces increased.

The data from the sensors confirmed the predictions made by NASA’s computer models. According to initial findings, the wing withstood the anticipated in-flight forces without issue. The results provided the team with confidence in the new manufacturing approaches and methods for connecting wing parts used in SWEET-15, which could support future efficient aircraft designs. The manufacturing approach, developed at NASA Langley used the Integrated Structural Assembly of Advanced Composites robot, aims to produce lighter and stronger composite structures for aerospace vehicles.

The test concluded with a deliberate test-to-failure, where engineers increased loads beyond the wing’s design limits to determine how and where it would fail. The structure ultimately failed at roughly 127% of its design limit load, with visible damage appearing near the back edge of the wing and in the upper wing cover. This element of testing provided valuable insight into how the joints connecting the wing to its main strut and a secondary one, called a jury strut, behave under forces beyond the expected flight envelope.

This marks the first time a representative composite truss-braced wing configuration has undergone this type of structural evaluation.  It was made possible only through NASA collaboration across centers and projects, with researchers utilizing agency resources such as the Fiber Optic Sensing System developed to gather data on both aircraft and spacecraft.

To prepare for the testing, engineers at NASA Langley designed, analyzed, and manufactured the wing and completed safety preparations and lab setup.

Researchers will now analyze the data collected during testing to inform future airframe designs and support NASA’s ongoing efforts to develop more efficient aviation technologies.

The work is being conducted through NASA’s Subsonic Flight Demonstrator project in the agency’s Research Technology Mission Directorate. The successful testing of multiple innovative components marks a milestone in NASA’s aeronautics research.

To learn more, visit:

https://www.nasa.gov/aeronautics/