NASA researchers have recently completed a series of wind tunnel tests on a seven-foot scale wing model to accelerate the development of advanced air mobility (AAM) aircraft. Conducted in May and June 2025 at NASA’s Langley Research Center in Hampton, Virginia, these experiments focus on propeller-wing interactions for tiltwing configurations—aircraft that transition between vertical takeoff and landing (VTOL) and forward flight by rotating their wings and rotors.
During testing in the 14-by-22-Foot Subsonic Wind Tunnel, technicians assembled and instrumented a semispan model, representing the right half of a full wing, with multiple propellers and over 700 sensors. These sensors measured pressure distribution, forces on the wing, and loads on individual motor-propeller hubs. The model was mounted on a precision turntable, allowing researchers to vary wing tilt angle, flap position, propeller rotation speed, and tunnel wind speed. By adjusting these parameters, the team simulated hover, transition, and cruise flight conditions and captured detailed data on how airflow and rotor wash affect wing performance.
“By testing multiple configurations and speeds, we can build a unique aerodynamic and acoustic database to validate next-generation design tools,” said Norm Schaeffler, test director at Langley. “These validated tools will enable aircraft designers to predict performance accurately, make informed decisions about safety margins, and shorten design cycles.” Brandon Litherland, principal investigator for the study, emphasized that sharing this data publicly will bolster the entire AAM industry, helping innovators refine electric air taxis, autonomous cargo drones, and other novel VTOL concepts.
The scale model’s semispan design enabled efficient testing of critical interactions without the complexity of a full-span wing. Within the tunnel, researchers also altered the relative positions of the propellers to understand how rotor placement influences lift, drag, and noise. Special force sensors beneath the wing tracked overall aerodynamic loads, while hub assemblies measured torque and thrust at each rotor. These measurements will feed into computational fluid dynamics (CFD) and aero-acoustic models, improving simulation fidelity for real-world flight scenarios.
This wind tunnel series is part of NASA’s Revolutionary Vertical Lift Technology project under the Advanced Air Vehicles Program, which supports the agency’s broader Advanced Air Mobility mission. By delivering high-quality experimental data, NASA aims to de-risk emerging AAM designs, inform certification processes, and guide industry standards. Once fully analyzed, the data set will be released on NASA’s public website, providing aircraft developers with open access to empirical results they can use to validate their own design tools.
The comprehensive testing campaign underscores NASA’s commitment to fostering innovation in electric and hybrid-electric VTOL aircraft. As startups and established aerospace companies race to bring air taxis and delivery drones to market, the insights from Langley’s wind tunnel will help ensure that the next generation of AAM vehicles is not only efficient and quiet but also demonstrably safe under a wide range of operating conditions.
