)[4] In 1940, the USGS mapped the "State Boundary" as a straight north-south line demarcating a small eastern portion of "Fairfax Airport" as being in Missouri.

[8] While Grandview Air Force Base was being completed, on 1 October 1952 Kansas City, Missouri, had CADF's Technical and Ground Training Division,[9] and the NSA's Special Study Group met on 1 August 1953 at "Headquarters, Central Air Defense Force, Kansas City, Missouri".

[13] In 1937 Fairfax acted as an "army reserve base" with Douglas O-46 observation planes,[14] and by 1938 the airport had four runways, including one 2,700 ft (820 m) long.

[23] The USAAF leased the Fairfax Airport from the city and the Works Projects Administration sponsored expansion of the four civilian runways.

The Fairfax Modification Center was a dual hangar built May–October 1942 along the south taxiway for altering the new B-25s (a west extension and several outbuildings were added.

The 81st AAF Technical Training Detachment activated 22 February 1943 and designated, effective 30 August, to supervise apprentice crew chiefs at the Modification Center.

January AAF policy was for each mechanic selected as a crew chief to be assigned an aircraft as it left the factory, review its modifications at the center, and deploy with it to the field unit.

[citation needed] Peak enrollment was 296 mechanics on 27 June, and the apprenticeship program was abandoned (the detachment inactivated on 31 October 1943.)

On 9 November 1944 the 33d Group furnished plane and crew to fly Senator Harry S. Truman from Fairfax to Washington for ceremonies following his election as Vice-President, and in early 1945 the 33d controlled ten operating locations.[where?].

[30][31] The Air Transport Command operating location at Fairfax was discontinued by 6 December 1945 (9 C-47s and 80 pilots/co-pilots transferred west to Topeka Army Airfield which had been chosen for a central MAT flight facility by November 1945.)

In October 1948, 37 Air Force Reserve planes at Fairfax flew 1,844 hours and in 1949, the 564th was replaced by the 442d Troop Carrier Wing (activated 27 June).

From 18 December 1953 – 1 March 1954, the 326th Fighter-Interceptor Squadron was assigned to Fairfax, and an F-84 crashed near the city's business district killing the pilot and three residents.