The 173rd ARS is the group's flying unit and has operated the KC-135R since 1994. The unit was formed as the 173rd Fighter Squadron in July 1946 and flew P-51Ds until August 1948, when it converted to the F-80C. The unit was redesignated the 173rd Fighter-Bomber Squadron with F-51s and mobilized from April 1951 until December 1952. Designation changed to 173rd FIS in September 1953 with F-80Cs, followed by F-86Ds in January 1957 and F-86Ls late in 1959. The unit joined the 155th FIG in July 1960. The 173rd was redesignated a TRS in May 1964 with conversion to RF-84F, followed by conversion to the RF-4C in February 1972.