At a simulated 27,500ft inside an altitude chamber at NASA’s Electric Aircraft Testbed (NEAT) facility, engineers at magniX recently demonstrated the capabilities of a battery-powered engine that could help turn hybrid electric flight into a reality.

This milestone, completed in April 2024, marks the end of the first phase in a series of altitude tests at the facility under NASA’s Electrified Powertrain Flight Demonstration (EPFD) project.

EPFD brings together expertise from NASA and various industry partners to test the feasibility of hybrid electric propulsion for future commercial aircraft.

NEAT, housed within NASA’s Neil Armstrong Test Facility in Sandusky, Ohio, offers a unique testing environment that simulates the effects of high altitudes without leaving the ground.

This capability allows researchers to safely evaluate the performance of electrified aircraft propulsion systems and components under realistic flight conditions. 

“The testing at NEAT is critical for high-power electrified aircraft propulsion technologies because many of the potential problems that a design might encounter only present themselves at higher altitudes,” said Brad French, lead systems engineer for NASA EPFD. “We do our best to analyse machines through sea-level testing, but nothing compares to actually putting them in the environments they will experience on wing and directly observing how they behave.”

At higher altitudes, electrified aircraft propulsion systems will be exposed to thinner air and greater temperature shifts that could negatively impact performance.

The initial round of tests focused on investigating the effects of temperature and high voltage on the electric engine when operating at flight levels.

Researchers conducted partial discharge tests, which examine the strength of the system’s electrical insulation, to help minimise risks of failure that might occur due to excess stress on the components.

They also investigated the engine’s thermal management system to better understand how heat is safely and effectively transferred throughout the machine.

“The development of new technologies is a methodical and incremental process,” French said. “By testing these systems in a controlled environment, we can verify that they operate safely and as expected, or isolate and solve any problems before they pose a significant risk.”

Under EPFD, magniX is retrofitting a De Havilland Dash 7 aircraft with a new hybrid electric propulsion system that combines traditional turbo-propellor engines with electric motors.

This vehicle will be used to demonstrate fuel burn and emission reductions in regional aircraft carrying up to 50 passengers, helping advance NASA’s mission to make air travel more sustainable. 

The company recently completed baseline flight testing of the Dash 7 in Moses Lake, Washington, surveying the state of the aircraft prior to modification.

Data gathered from these flight tests will help the team compare fuel savings and performance boosts with the new electrified system.

With baseline flight tests complete, magniX will begin modifying the aircraft in preparation for hybrid electric flight tests planned for 2026. 

In the meantime, the next phase of ground tests at NEAT is slated for the summer of 2024 and will evaluate these systems under more extreme flight conditions, including higher power levels and temperatures.

Each round of testing will provide more insight that will eventually help identify new standards and regulations required for future electrified aircraft. 

In addition to magniX, NASA works with GE Aerospace to explore other design configurations and approaches for hybridising commercial aircraft. GE also completed altitude tests of their hybrid electric propulsion system at NEAT in 2022. 

NASA, with GE and magniX, are accelerating the development and introduction of electrified aircraft propulsion technologies through NEAT while gathering a rich archive of scientific data.

This will help inform advanced electrified aircraft propulsion system concepts and formulate new research areas and technologies to enable a sustainable aviation future. 

www.nasa.gov