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. Twenty years later, when the last 727 was delivered, this versatile fleet was carrying 13 million passengers each month.