American Airlines on Tuesday agreed to buy 20 supersonic jets that can travel at 1,300 miles per hour but are years away from hitting the friendly skies.

The Texas-based airline put down a non-refundable deposit for the fleet of Boom Supersonic Overture jets and has the option to buy 40 more.

Boom calls its planes the “world’s fastest airliner” because they can make it from Miami to London trip in just under five hours or Los Angeles to Honolulu in three.

Tickets to fly from New York to London — a three and a half hour trip — would cost about $4,000 to $5,000.

The supersonic jets would be used by American Airlines for international travel only, as planes must stay below the speed of sound while traveling over land, reported the Dallas Morning News. The Overture could ramp up to Mach 1.7 over water and carry 65 to 80 passengers.

The jets are still in the experimental phase, but Boom hopes to conduct flight testing as early as 2026. Passengers could be traveling in the Overturn as early as 2029 if all goes well.

Last year, United Airlines agreed to purchase 15 Boom jets, which will fly entirely on sustainable aviation fuel, often made from plant material.

Supersonic jet travel died off two decades ago after the Concorde was retired by Air France and British Airways after a deadly crash and high fuel and maintenance costs.

With Post wires