11/15/2006. Remarks by Johan Visschedijk: "The prototype of the Learjet 35 (originally known as Learjet 26) flew for the first time on January 4, 1973. The type was selected for the Operational Support Programme to replace the CT-39 Sabreliners in the USAF inventory. On September 19, 1983, Gates received a contract for lease to the USAF of 80 Learjet 35As, designated C-21A, s/ns 84-0063 to 84-0142 (c/n 35A-509 to 35A-588. The first aircraft was rolled out at Tucson, Arizona, USA, on March 13, 1984, the last one was delivered in October 1985. The 80 aircraft were purchased by the USAF on September 30, 1986."