When Boeing's assistant director of flight operations Brien Wygle and chief test pilot Lew Wallick lifted the first 737 from Boeing Field on April 9, 1967, the twinjet was merely a modest supplement to the trijet 727. No one imagined it would long be the best-selling jet airliner, but the Airbus A320 family overtook it in orders in 2019 and in deliveries in 2025. The initial -100, only ninety-four feet long and carrying 115 passengers, was so lightly ordered that only thirty were built. But the stretched -200 found a home in the world's short-haul routes, and the type began a slow accumulation of orders that would span six decades and four generations. Lufthansa became the first operator on February 10, 1968, the first non-American airline to launch a new Boeing design. The 737's genius was its simplicity: a fuselage wide enough for six abreast, two underwing engines, and a ruggedness that let it thrive on gravel strips and glass runways alike. As of April 2026, more than 12,520 have been built, serving over 500 airlines in 190 countries. One-quarter of all jet airliners in the world wear the 737 name. Wygle had radioed down during the maiden flight, "I hate to quit, the airplane is a delight to fly." Millions of departures later, the delight endures.