n addition to domestic flights of medium range, the 727 was popular with international passenger airlines. The range of flights it could cover (and the additional safety added by the third engine) meant that the 727 proved efficient for short- to medium-range international flights in areas around the world.
It was the first commercial airplane to break the 1,000-sales mark, but it started out as a risky proposition. The 727 was designed to service smaller airports with shorter runways than those used by Boeing 707s.
Adding to Boeing’s challenges were conflicting demands from customers: some wanted four engines, another wanted a twin, still others were satisfied with prop planes. Boeing was also still grappling with the startup and production costs of the 707.