US carrier Southwest Airlines plans to jointly develop a fleet of electric air taxis to serve the California market with transportation startup Archer Aviation, the companies announced Friday.

The two companies signed a memorandum of understanding envisioning Southwest making use of Archer's "Midnight" aircraft throughout the nation's largest state, offering short trips from California's 14 airports.

Begun as an aviation venture in 2018, Santa Clara, California-based Archer has been working to gain Federal Aviation Administration certification of its electric vertical takeoff and landing (eVTOL) aircraft.

The company's Midnight eVTOL can carry four passengers in addition to a pilot.

The aircraft is "designed to transform urban travel, replacing 60-to-90-minute commutes by car with estimated 10-to-20-minute electric air taxi flights," said a joint press release.

"The goal of Archer's aircraft is to offer a safe, low-noise, cost-competitive transportation option with no direct emissions."

The Southwest venture follows a joint announcement from Stellantis and Archer earlier this month in which the automaker agreed to an additional $55 million investment in the startup.

Southwest -- the fourth biggest US carrier after American, United and Delta -- is "eager to explore the convenience Archer's air taxis could provide customers flying Southwest at airports in busy urban areas," said Paul Cullen, a vice president for real estate at Southwest.

In June, Archer received an FAA certificate to begin commercial operations to refine and improve its systems ahead of launching for Southwest and United Airlines, which also has collaborated with the company. Archer could receive FAA certification as soon as 2025, an Archer spokeswoman said.

"We are now in the final phase of certification with the FAA known as the 'implementation phase' and will begin crewed 'for credit' testing with the FAA next year which are the final sets of flight tests we are required to pass prior to obtaining Type Certification for our Midnight aircraft," the Archer spokeswoman said in an email.

On Tuesday, French officials gave the go-ahead for construction of a floating landing pad on the River Seine for flying taxis set to be shown off during the Paris Olympics.