Boeing 727 is a medium and short range civil aviation aircraft developed and produced by Boeing Company in the United States. It is the world's first commercial three engine jet civil aircraft, and before being replaced by the Boeing 737, it was the most popular civil aircraft in the world. The Boeing 727 is the second jet passenger aircraft of Boeing Company in the United States, which underwent a test flight in 1963. The number of passengers is 145 (first class, economy class layout) or 189 (full economy class layout), which is driven by three turbojet engines. Some parts, such as fuselage components, are the same as Boeing 707, and the main market is the inland trunk line of the United States. The Boeing 727 adopts a design similar to the Trident, with all three engines installed at the rear of the aircraft. The last one was delivered for use in 1984, with a total production of 1832 units. Before the production of the Boeing 737, it was the world's largest production jet passenger aircraft.