Shortly thereafter, Aero Commander was acquired by North American Rockwell. The Jet Commander created a problem, since Rockwell already had an executive jet of its own design, the Sabreliner, and could not keep both in production because of anti-trust laws. Therefore, the company decided to sell off the rights to the Jet Commander, which were purchased by IAI in 1968.
Jet Commander production amounted to 150 aircraft in the United States and Israel before IAI undertook a series of modifications to create the 1123 Westwind. These included stretching the fuselage and increased maximum takeoff, maximum landing, and maximum zero-fuel weights, with the wing modified to incorporate double-slotted flaps and drooped leading edges and tip tanks. The trimmable horizontal stabiliser was also modified to have increased span and more travel. Not long after the aircraft went into production, the original General Electric CJ610 turbojet engines were replaced by more fuel-efficient Garrett TFE731 turbofans There were also numerous airframe modifications, such as drooped leading edges on the wings, a dorsal fin, revised engine pylons and nacelles, and further increases in maximum takeoff, maximum landing, and maximum zero-fuel weights. With improvements to a number of onboard systems incorporated as well, these changes resulted in the 1124 Westwind delivered from 1976.
In 1976, in the wake of the terrorist takeover of the Savoy hotel in Tel Aviv, the Israeli Air Force decided to use the Westwind as the basis for a maritime patrol aircraft, which became known as the IAI Sea Scan.
In 1980, deliveries of the Model 1124A commenced; modifications included a new wing centre-section and the addition of winglets to the tips. The revamped aircraft was called the Westwind II, replacing the original design in production. IAI built its last Westwind in 1987, after a total of 442 Jet Commanders and Westwinds had been built, switching production to the Astra.