Delta Air Lines has made an upfront equity investment of $60 million in Santa Cruz, Calif.-based Joby Aviation, which is developing electric vertical takeoff and landing (eVTOL) aircraft, the companies announced Tuesday.

Delta plans to use the new aircraft for home-to-airport transportation for its customers, beginning in New York and Los Angeles. The investment could increase to up to $200 million based on the achievement of milestones on the development and delivery of the service.

The companies did not state a beginning date for the service, but Joby has said it plans to launch air taxi service in 2024.

The Delta and Joby operations will run alongside Joby’s standard airport service in priority markets, and the partnership will be mutually exclusive across the United States and the United Kingdom for five years following commercial launch, with the potential to extend that period, according to the companies.

Joby’s aircraft have flown more than 1,000 test flights and recently received Part 135 Air Carrier Certification from the U.S. Federal Aviation Administration, according to the company.

Additional carriers with investments in Joby include All Nippon Airways, and JetBlue has been an investor since 2017. Joby went public in 2021 via a special purpose acquisition company. In addition, Joby has partnered with South Korean’s SK Telecom to bring aerial ridesharing services across South Korea, and Toyota Motor Corp. has invested in the company.

Joby Aviation and Skyports Infrastructure are developing a moveable passenger terminal, called a “Living Lab,” where they will test technologies and procedures to shape how customers experience eVTOL flight.

Delta joins a number of carriers in investing in eVTOL aircraft. United Airlines paid a $10 million cash deposit in August to Santa Clara, Calif.-based Archer Aviation for 100 of the company’s electric vertical aircraft. Less than one month later, United invested $15 million in Eve Air Mobility with an agreement to purchase up to 400 of its electric vertical take-off and landing aircraft. Mint Air ordered up to 40 Jaunt eVTOL aircraft last month. Late last year, regional carriers Republic Airways and SkyWest signed nonbinding letters of intent to purchase eVTOL aircraft from Embraer-controlled Eve Air Mobility.