Designing the Boeing 747, for instance, the world's first jumbo jet, took over three years and US $ 2 billion, with 13,000 hours of wind tunnel tests.
以波音七四七﹘﹘全世界第一部巨無霸噴射客機為例，從設計到製造，共花了三年時間、二十餘億美金、一萬三千小時風洞實驗。