The Learjet 40 is derived from the Learjet 45 but with a shorter fuselage (by 24.5 inches/60 cm), and is powered by two Honeywell TFE731-20AR engines. The prototype aircraft, a rebuilt Model 45, first flew on August 31, 2002, and the first production aircraft performed its maiden flight on September 5, 2002. Both flights took place from the Wichita Mid-Continent Airport. The LJ40 entered into service in January, 2004.