American Airlines agrees to buy 20 supersonic planes from Boom

Blake Scholl, the CEO of Boom stands in front of the XB-1 aircraft that Boom Supersonic is using to test the avionics of their proposed aircraft, with which they hope to resurrect commercial supersonic air travel across the Atlantic, in Centennial, Colorado, August 13, 2021.

American Airlines will purchase 20 supersonic planes from Boom Supersonic.

The second firm order in the last two years for Boom is still years away from being built. The airline made a commitment to buy 15 jets.

"Passengers want flights that are faster, more convenient, more sustainable and that's what Overture delivers," said Boom's CEO In networks like American, we can fly from Miami to London in less than 5 hours.

The jet will be able to fly as fast as Mach 1.7, or 1, 304 mph, cutting trans-Atlantic and trans-Pacific flight times in half. A flight from Seattle to Tokyo can be completed in six hours in an Overture.

American's chief financial officer said that supersonic travel will be an important part of the company's ability to deliver. A non-refundable deposit is being paid by American.

There is an option for the airline to buy another 40 Overtures in the future.

A mock up of Boom Supersonic’s proposed “Overture” plane. The U.S. firm has said it is targeting the mid-2020s for it to enter service.

Boom says it will carry up to 80 passengers on its supersonic planes.

It's years away from being a reality. The first model of the jet will be built at a new manufacturing plant in North Carolina and is expected to be in the air by the year 2026. According to Boom, the Overture will enter commercial service by the end of the decade.

CNBC'sMeghan Reeder contributed.