[Pan American Airways founder Juan Trippe] had the big idea," Virgin Atlantic founder Richard Branson once recalled. "He reasoned that mass air travel could come to the international routes only with a larger airplane -- a much larger airplane. Trippe put the notion to his old friend Bill Allen, the boss of Boeing, saying he wanted a jet [the Boeing 747] two-and-a-half times the size of the 707. It was a staggering request given the development cost of the 707. And Trippe didn't stop with size. Pam Am was operating the 707 with a seat-mile cost, at best, of 6.6?. Trippe set for Boeing the goal of reducing that 30%. 'If you build it,' said Trippe, 'I'll buy it.' 'If you buy it,' said Allen, 'I'll build it.' My kind of guys."