 On 31 January 1972 , the 170th Tactical Fighter Squadron / <unk> Tactical Fighter Group of the Illinois Air National Guard became the first Air National Guard unit to transition to Phantoms from Republic F @-@ 84F <unk> which were found to have corrosion problems . Phantoms would eventually equip numerous tactical fighter and tactical reconnaissance units in the USAF active , National Guard , and reserve . 
