Boeing 727 is a medium and short-range civil aircraft developed and produced by Boeing company of the United States. It is the first commercial three engine civil aviation aircraft in the world. It was the most popular civil aviation aircraft in the world before it was replaced by Boeing 737. [1] Boeing 727 is the second jetliner of Boeing company of the United States, which was tested in 1963. With 145 passengers (first class, economy class layout) or 189 passengers (full economy layout), it is driven by three turbojet engines. Some parts, such as fuselage components, are the same as those of Boeing 707. The main market is the US inland trunk line. Boeing 727 adopts a trident like design, with all three engines installed in the tail of the aircraft. The last one was delivered in 1984 with a total production of 1832. Before the Boeing 737 went into production, it was the world's largest production jet.