US-based eVTOL aircraft developer Joby Aviation is beginning testing at the National Full-Scale Aerodynamic Complex (NFAC), the world's largest wind tunnel facility, at NASA's Ames Research Center in Silicon Valley, California.

The NFAC is managed by the US Air Force Arnold Engineering Development Complex and contains the two largest operational wind tunnels in the world. Data from propeller testing in the NFAC, widely considered to be the gold standard for aircraft aerodynamics and performance, was instrumental in the development of a range of iconic vehicles such as the space shuttle, the V-22 Osprey, the F-35 Joint Strike Fighter and a number of next-generation helicopters.

Joby is believed to be the first eVTOL company to test its propeller in the NFAC's 40x80 ft wind tunnel.

“Testing is a critical part of our aircraft programme, and the opportunity to gather data on the performance of our propellers in one of the world's largest wind tunnels is an exciting step toward commercialisation,” says founder and CEO JoeBen Bevirt. “This facility helped introduce historic aircraft to the world, and now it's doing the same for the next generation of sustainable aviation.”

AFWERX Prime programmes lead Lt Col Tom Meagher adds: “A cornerstone of the AFWERX Agility Prime programme is fostering interagency partnerships and collaboration to progress the advanced air mobility segment. The NFAC testing is a perfect example of utilising unique government test resources and infrastructure critical to enabling industry progression.”

The test campaign will cover all tilt angles and speeds through the expected flight envelope, providing Joby with consistent and high-fidelity data on the performance, loads and acoustics of its propeller systems in support of its certification programme with the FAA.

Working in partnership with the US Air Force and NASA, Joby is installing a production-intent electric propulsion unit and propeller assembly in the wind tunnel mounted to a six-degree-of-freedom force and moment balance to capture performance data. The blades are instrumented to measure the loads experienced while rotating, and a representative wing section of the Joby aircraft allows careful analysis of aerodynamic interference effects.

The NFAC propeller test campaign is expected to produce data of unparalleled quality, exceeding what is captured during normal flight testing, due to superior instrumentation and precise control of variables. The full test campaign is expected to take several months to complete.

Joby and NASA previously partnered on a variety of projects exploring electric aircraft technology, including the design of the agency's all-electric X-57 Maxwell prototype. The agency also completed a two week acoustic testing programme with Joby in 2022 as part of its Advanced Air Mobility National Campaign.

With more than 1,000 test flights completed, Joby's piloted, all-electric aircraft is designed to offer a faster and quieter method of aerial transportation across cities and communities with zero operating emissions. Commercial aerial ridesharing services could launch in the US in 2025.