The MD-90 is a successor model of the McDonald Douglas MD-80 in the United States. The fuselage has been extended, equipped with an IAE V2500 engine, the cabin has been improved, and the vertical tail has been enlarged. The first prototype flew for the first time on February 22, 1993, obtained the airworthiness certificate of the Federal Aviation Administration on November 16, 1994, and was delivered to users on February 24, 1995. I started serving at Delta Airlines on April 1, 1995. This model has delivered a total of 114 units and has been discontinued. In 1997, Boeing merged with McDonnell Douglas, causing a conflict between the MD-90 and Boeing's product line, and production ceased in 2000.