American Airlines is purchasing 20 of Boom's supersonic Overture jets

One of the world’s largest airlines has placed a big bet on supersonic jet startup Boom. On Tuesday, American Airlines announced that it had recently agreed to buy 20 Overture aircraft from Boom, with the option to purchase an additional 40 planes if all goes well. The deal is one of the strongest shows of support for Boom yet, surpassing the potential 50-jet commitment United Airlines made last year. That’s all for a startup that has yet to build a working passenger jet.