The 727, like all Boeing jetliners, was continually modified to fit the changing market. It began with the -100 series, of which 407 were sold. This was followed by the -100C convertible that featured a main-deck side cargo door, allowing it to carry either cargo pallets or passengers -- or a combination of both -- on the main deck. Boeing built 164 of these.
The 727-200, introduced in December 1967, had increased gross weight and a 20-foot longer fuselage that could accommodate as many as 189 passengers in an all-tourist configuration. In all its variations, 1,245 of the -200s were sold. The last version, the 727-200F, was introduced in September 1981 and had a 58,000-pound, 11-pallet cargo capability. Fifteen of these were sold to Federal Express. Production of the 727 extended from the early 1960s to August 1984 -- a remarkable length of time, considering the original market forecast was for 250 airplanes. As it turned out, 1,831 were delivered.