Raytheon Beechjet airplane model. The Raytheon Beechjet traces its origins back to the Mitsubishi Diamond 2 bizjet, which Beechcraft acquired the design and production rights to in the mid 1980s.
Beech reengined the Diamond 2 with PWC JT15D5 turbofans, developed a new interior, and incorporated a number of other minor refinements. Deliveries of the Beech jet began in June 1986, with low-rate production continuing until that model was replaced by the Model 400A, which was delivered from November 1990.
The new 400A incorporated a number of improvements over its predecessor. A higher max takeoff weight and greater operating ceiling improved performance, while repositioning the rear fuselage fuel tank increased cabin volume.