The Westwind started out as the Aero Commander 1121 Jet Commander. When Rockwell (owner of Aero Commander) acquired North American Aviation (owner of Sabreliner) in 1967, the Justice Department ordered Rockwell to sell one of the companies because of antitrust law violations. The design and production rights for the Jet Commander were sold to IAI in 1968.
IAI completed production of the 1121 Commodore Jets then introduced a stretched version, called the Commodore Jet 1123. in 1976, IAI introduced the Westwind (Model 1124). The Westwind came equipped with the efficient Honeywell TFE731-3 engines and a modified wing with tip tanks. The Westwind became the Westwind I in 1979 when a 104-gallon long-range fuel tank was added.