https://www.siliconvalley.com/2023/01/31/farewell-queen-of-the-skies/

The first and final 747 jumbo jet models both started with a handshake deal.

Back in the mid-1960s, the leaders of Boeing Co. and PanAm came to an agreement that if the US planemaker pushed ahead with the audacious new design, the airline would in turn go ahead and buy the giant jetliner.