"We are one of the few companies acknowledging there are different missions and different vehicle types for different missions," Mr. Reuter said.

Volocopter is pursuing regulatory approval with the European Union Aviation Safety Agency and hopes to have its aircraft in operation by 2024.

Joby, based in Santa Cruz, Calif., is pursuing a similar goal using yet another approach, having flown over 1,000 test flights on its fully electric aircraft, which seats four passengers plus the pilot and has a range of 150 miles on a single charge. The company made headlines last December when the ride-sharing giant Uber offloaded Elevate, their urban air travel ride-sharing product, to Joby and invested an additional $75 million into the company, signaling that the two services would be seamlessly linked.

Cities are already preparing for the introduction of electric aircraft to their already overburdened transportation systems. Mayor Eric Garcetti of Los Angeles set up Urban Movement Labs in 2019; today the organization is focused on preparing for the certification of electric aircraft for public use by the F.A.A. as early as 2025.

The F.A.A. declined multiple requests for an interview, but said it is reviewing electric aircraft on a case-by-case basis.

Mayor Francis Suarez of Miami said his city is embracing eVTOLs as a cost-effective, environmentally friendly alternative to legacy modes of transportation like buses and light rail, which are costly to build and rely on older technology. He said the city is looking at parking garages, rooftops and other potential takeoff and landing locations.

"We feel that one of the flaws in transportation planning and funding has been retreading yesterday's ideas," he said in an interview. "The sky obviously has multiple dimensions and gives you the ability to be creative."