Although the 747-200 was developed after the 747-100, it was built during roughly the same time frame. The first -200 went into commercial service in 1971, and Boeing delivered a total of 393, the last in 1991. Although its external appearance is nearly identical to the 747-100, it was designed to carry more payload. In addition to being offered as a passenger airplane, the -200 was the first 747 to be configured as a freighter, a combination passenger-freighter and a convertible.
From the beginning, the 747 was designed to serve as an all-cargo transport. The first 747 Freighter could easily carry 100 tons (90,000 kg) across the Atlantic Ocean or across the United States. Its operating cost was 35 percent less per ton mile than the 707 Freighter. The 747 Freighter has a hinged nose to allow cargo loading through front of the airplane, with the option of a large side-cargo door.
The 747-200 Convertible was configured to serve as a passenger airplane, a freighter or a combination of both. This airplane responded to airlines' needs to carry different payloads at different times of the years, such as higher passenger capacities during the summer and more cargo during the winter. Similar to the convertible is the -200 Combi, which was designed to serve as a passenger-only airplane or as a passenger-freighter mix.
The combi has a large side-cargo door on the main deck, and is used by airlines to make better use of their routes during different times of the year. The convertible has a nose cargo door similar to the freighter.