Boeing 727
American Airlines

Boeing 727-200 in AA livery. AA was the dominant operator of the 727-200, having purchased 125 aircraft of the -200 variant, and 59 of the -100 type.

Other major operators of the Boeing 727 -100 and -200 variants over the years included United Airlines (126+104), Delta Air Lines (8+183), and Eastern Air Lines (75+99). Outside the US, the largest operators were Mexicana de Aviación (68), Lufthansa (57), Avianca (51), and Iberia (48). Reference: simpleflying.com/boeing-727-rise-fall-story/