An early example of the first Learjet variant, built in 1964. It was registered to Louise B. Timken (Canton, OH) on 27 June 1968. She operated it in this livery until 1992, when she donated the aircraft to the Pima Air Museum. Registration cancelled on 1 April 1992.

The Model 23 is the first of Learjet's series of small business jet aircraft. First flown in 1963. Markings shown by this airframe on display at Pima: Ms. Louise Timken, 1992

Early Learjet (first flown 1963) in the main building at Pima Air and Space Museum. The jet was privately owned and donated to the museum in the year 1992

Operated privately from 1964 until 1992, when it ended up at Pima.