▁He ▁returned ▁to ▁the ▁United ▁States ▁in ▁February ▁ 1 9 5 3 ▁and ▁was ▁assigned ▁to ▁the ▁ 4 2 4 0 th ▁Com bat ▁C rew ▁Training ▁Wing ▁at ▁Mc Co y ▁Air ▁Force ▁Base , ▁Florida , ▁where ▁he ▁trained ▁pil ots ▁in ▁F - 8 4 s ▁and ▁T - 3 3 s ▁for ▁combat ▁duty ▁in ▁Korea . ▁In ▁June ▁ 1 9 5 4 ▁Nich ol son ▁transferred ▁to ▁Mc Con nell ▁Air ▁Force ▁Base , ▁Kansas , ▁where ▁he ▁was ▁director ▁of ▁mater iel ▁for ▁the ▁ 3 5 2 0 th ▁T act ical ▁F ighter ▁Group . ▁His ▁next ▁assignment ▁was ▁with ▁Head quarters ▁Air ▁Training ▁Command ▁at ▁Rand olph ▁Air ▁Force ▁Base , ▁Texas , ▁where ▁he ▁served ▁as ▁an ▁air ▁operations ▁officer ▁from ▁June ▁ 1 9 5 5 ▁to ▁September ▁ 1 9 5 9 . ▁He ▁then ▁attended ▁Air ▁Command ▁and ▁Staff ▁College . ▁ ▁Nich ol son ▁transferred ▁to ▁the ▁Republic ▁of ▁Vietnam ▁and ▁was ▁assigned ▁to ▁the ▁Military ▁Ass istance ▁Ad vis ory ▁Group , ▁Vietnam ▁at ▁Bien ▁Ho a ▁Air ▁Base ▁as ▁air ▁operations ▁advis er ▁to ▁the ▁ 1 st ▁F ighter ▁Squadron ▁of ▁the ▁Republic ▁of ▁Vietnam ▁air ▁force . ▁During ▁this ▁tour ▁of ▁duty , ▁he ▁fle w ▁ 2 0 0 ▁combat ▁miss ions ▁in ▁A - 1 ▁Sky ra iders . ▁Because ▁of ▁his ▁combat ▁experience ▁he ▁was ▁selected ▁by ▁the ▁commander ▁in ▁chief ▁of ▁Pacific ▁Air ▁Forces ▁to ▁serve ▁as ▁staff