Te 1950s began with 40 million automobiles registered in the United States, according to the US Federal Highway Administration. By the end of the decade, that number had increased to 59 million. With ground transportation increasingly snarled, helicopter operators began providing shuttle service within the cities of Chicago, Los Angeles, San Francisco, and New York. Chicago Helicopter Airways at one point was carrying 25,000 passengers each month to
points around the city. Today, advanced air mobility is once again
making headlines as that sector experiences an explosive wave of development, spurred by advances in lightweight materials, electric propulsion, and autonomous systems. Te Vertical Flight Society is tracking more than 900 concepts for electric vertical takeoff and landing (eVTOL) aircraft, and several models are being flight-tested.