American Airlines and Virgin Atlantic each are partnering with a U.K.-based aeronautical firm developing electrical aircraft with vertical takeoff and landing capabilities, with plans to add the vehicles to their respective fleets.

The firm, Vertical Aerospace, is developing the VA-X4 aircraft, which runs with no carbon emissions and is capable of carrying four passengers and a pilot at a range of more than 100 miles at speeds of 200 miles per hour. Vertical expect to have the aircraft ready for test flights later this year and certification to fly as early as 2024.

American’s agreement includes a $25 million investment in Vertical via a private investment in public equity transaction as well as a pre-order commitment, subject to its terms being met, of up to 250 aircraft, valued at about $1 billion. The agreement includes an option for an additional 100 aircraft on top of those.

American could use the aircraft to move travelers around urban centers and to airports, according to the carrier.

Virgin Atlantic, meanwhile, has agreed to an option to buy up to 150 aircraft, and it also is exploring a joint venture with Vertical Aerospace to develop a short-haul network branded by Virgin Atlantic. That network initially would connect U.K. cities and airport hubs, including London’s Heathrow and Gatwick airports and Manchester.

The 56-mile trip from Cambridge to Heathrow with the aircraft, for example, would take 22 minutes, compared with an hour and a half by car.

Vertical Aerospace is one of several companies with electric-powered vertical takeoff and landing aircraft under development. United Airlines earlier this year announced a partnership with another such company, Archer, and JetBlue is a long-time investor in Joby Aviation, which announced plans to go public earlier this year. Like Vertical, Archer and Joby each aim to have commercial flights by 2024.