Demo
    A white multicopter drone is flying in front of a tall, blue-glass building on an overcast day.
    A pilot flies Volocopter’s 2X test model in Singapore. The company proposes building vertiports, where passengers would board and exit its urban air mobility craft.
    A sleek white electric vertical takeoff and landing aircraft (eVTOL) is parked on a flat surface with forested hills in the background. It has six rotors and a compact, futuristic design.
    Joby Aviation plans to fly its prototype air taxi in NASA’s Advanced Air Mobility National Campaign, formerly the UAM Grand Challenge.
    A small drone flies above a rural road, with trees lining the background and a few clouds in the sky. A stop sign and gate are visible on the left side of the road.
    The autonomous EHang 216 flies a demonstration for state officials in North Carolina. The two-seat aircraft did not carry passengers for the flight.
    A white multicopter aircraft with eight rotors is stationed on a concrete surface. Two people are seated inside the cockpit, preparing for a flight. A runway and some trees are visible in the background.
    Aspiring passengers could only sit in the two-seat EHang 216 when it was on the ground.
    A colorful computer-generated visualization of airflow patterns around a rotating vertical-axis wind turbine, displayed against a dark background.
    The white swirls behind and below the rotorcraft in this simulation depict the pressure waves caused in part by interactions of the aircraft’s side-by-side rotor blades with vortices from the other blades, a main source of rotorcraft noise. Patricia Ventura Diaz of NASA’s Ames Research Center in Silicon Valley produced the simulation of the conceptual air taxi with a high-fidelity, computational fluid dynamics software.