Several examples of the Aero Commander light twin-engine transport went into service with the USAF and US Army. (4) prototypes were built, three for the Army (YL-26) and one for the USAF (TL-26A), equivalents of the commercial 520 and 560 respectively. The USAF purchased 15 L-25B (commercial 560A) for staff transports. (2) L-26Cs (equivalent to 680 Super) were purchased for Presidential use. The USAF versions were redesignated U-4A and U-4B in 1960.

WR-ALC was responsible for system program management and logistics support for all USAF U-4s during their operational service. The U-4 on display is a civilian example of the USAF version of the aircraft. It was acquired by the Museum in 1986.