Progress in the Wind 

Joby Aviation, Inc., the Santa Cruz-based maker of electric Vertical Takeoff and Landing (eVTOL) aircraft, announced on 16 February 2023 that it has begun testing the rotors by which its eVTOL will be compelled aloft. Subject tests are being conducted at NASA’s Ames Research Center’s National Full-Scale Aerodynamic Complex (NFAC)—the world’s largest wind tunnel facility.

Nestled among Silicon Valley’s high-dollar installations and managed by the U.S. Air Force’s Arnold Engineering Development Complex, the NFAC contains the world’s two largest operational wind tunnels. Data gleaned from testing at the two breezy facilities is widely considered the gold standard for the evaluation of aircraft and airfoil efficiency and performance. The NFCA wind tunnels were instrumental in the development of iconic machines the likes of NASA’s Space Shuttle, Bell-Boeing’s V-22 Osprey, and Lockheed-Martin’s F-35 Lightning II fighter.

Joby is believed to be the first eVTOL concern to test its rotor design in the NFAC’s forty-by-eighty-foot wind tunnel.

Joby founder and CEO JoeBen Bevirt remarked: “Testing is a critical part of our aircraft program 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 commercialization.” Mr. Bevirt added: “This facility helped introduce historic aircraft to the world, and now it’s doing the same for the next generation of sustainable aviation.”

Lieutenant Colonel Tom Meagher, who heads up the USAF’s AFWERX Prime programs commented: “A cornerstone of the AFWERX Agility Prime program is fostering interagency partnerships and collaboration to progress the advanced air mobility segment. The NFAC testing is a perfect example of utilizing unique government test resources and infrastructure critical to enabling industry progression.”

By dint of the AFWERX program, USAF brass seeks to promote an innovative intra-service culture, the expertise, experience, and collective endeavors of which will increase the branch’s combat lethality while lowering its research and development expenditures. Structurally similar to Air Force Special Operations Command, AFWERX has been described as an Island of misfit toys for entrepreneurs within the service.

By examining rotor-blade angles-of-attack, rotational speeds, aerodynamic loads, and acoustics throughout the flight envelope of the company’s inchoate eVTOL, the NFAC test campaign will provide Joby’s engineers consistent, high-fidelity data germane to the aircraft’s eventual type certification by the Federal Aviation Administration (FAA).

Joby’s testing itinerary calls for a production-intent specimen of the company’s electric propulsion unit and rotor assembly to be installed in the NFAC wind tunnel. The powertrain is to be mounted to a six-degree-of-freedom force and moment balance, and the rotor assembly’s blades will be instrumented for purpose of measuring the aerodynamic and mechanical loads imparted to such during rotation. To facilitate comprehensive analysis of aerodynamic interference phenomena, a wing section representative of Joby’s eVTOL will also undergo wind tunnel evaluation.

Owing primarily to the superior instrumentation of the NFAC’s wind tunnels and the precise control of variables occasioned by the immense contraptions, Joby expects its rotor test campaign to yield data of unparalleled quality—exceeding, even, that captured during actual in-flight testing. From start to finish, the testing regimen will span several months.

Previously, Joby and NASA partnered on a variety of projects pertaining to electric aircraft and their constituent technologies—including the design of the space agency’s all-electric X-57 Maxwell prototype.

Presuming development proceeds in accordance with specifications thus far set forth by the company, Joby’s eVTOL will come to market as a piloted, four-passenger commercial aircraft with a single-charge range of 130-nautical-miles and a maximum speed of 174-knots. The electrically-powered, ostensibly zero-emission machine is designed to be one-hundred-times quieter than a conventional helicopter during takeoff and landing. Joby plans to mass-produce its eVTOL and utilize a fleet of such to operate a piloted on-demand air-taxi service.

FMI: www.jobyaviation.com