The 1866th provided worldwide flight inspection for DoD air navigational aids/air traffic control radars along with flight inspection of air traffic control and landing systems. This service was provided to any fitting host nations as required. Although operations were all over the world, the squadron was based at Scott AFB, Illinois. When MAC took control of all Facility Checking Squadrons, the 1866th Facility Checking Squadron disbanded on October 1, 1987 but some sources have the disbanding date as May 15, 1971.
Established as a test squadron which carried out a special mission of satellite catching/ Originally flew the C-119J Flying Boxcar in 1958 and then began to transition to the JC-130B in 1961. During it's time of operating the C-130, the squadron was under the command of the 6594th Recovery Control Group based out of Hickam AFB, Hawaii. Flights over a target recovery area would be spaced out multiple aircraft within predetermined "boxes" for maximum coverage. Signals from the descending satellite could be triangulated and the C-130 in the best position would recover the satellite. Aerial recovery was best as salty ocean water could cause damage to the satellite. Helicopters also flew with the squadron in case of water recovery. Inactivated on July 1st, 1972 and the role continued under the main command of the 6594th Test Group.