The Citation X was first announced in October, 1990, as an improvement over the aging Citation 650 series. The aircraft first flew on December 21st, 1993, and entered service in 1996 after a number of issues with it were fixed, including engine flame outs and directional stability challenges. The Citation X went on to set a record for the civilian jet aircraft. It is still in production today, with an upgraded version, the New Citation X, currently in development.