▁V ought ▁F - 8 ▁Cr us ader ▁had ▁already ▁been ▁accepted ▁as ▁a ▁" day " ▁dog fig h ter , ▁while ▁the ▁sub son ic ▁Mc D onn ell ▁F 3 H ▁Dem on ▁was ▁the ▁Navy ' s ▁all - we ather ▁f ighter . ▁The ▁Ph antom ▁was ▁developed ▁as ▁the ▁Navy ' s ▁first ▁su person ic , ▁all - we ather , ▁rad ar - equ ipped ▁f ighter ▁armed ▁with ▁rad ar - gu ided ▁miss iles . ▁However , ▁compared ▁to ▁early ▁air - super ior ity ▁designs ▁such ▁as ▁the ▁F - 1 0 0 ▁or ▁F - 8 , ▁the ▁massive ▁Ph antom , ▁never theless , ▁had ▁enough ▁raw ▁tw in - J 7 9 ▁power ▁to ▁prove ▁adapt able ▁as ▁the ▁preferred ▁platform ▁for ▁tang ling ▁with ▁ag ile ▁Mi G - 1 7 ▁and ▁Mi G - 2 1 ▁f igh ters ▁over ▁the ▁sk ies ▁of ▁Vietnam , ▁as ▁well ▁as ▁replacing ▁the ▁US ▁Air ▁Force ▁Con v air ▁F - 1 0 2 ▁D elta ▁D agger ▁and ▁Con v air ▁F - 1 0 6 ▁D elta ▁D art ▁for ▁contin ental ▁inter ception ▁duties ▁and ▁the ▁Republic ▁F - 1 0 5 ▁Th under ch ief ▁as ▁a ▁medium ▁f ighter - b om ber . ▁The ▁need ▁for ▁close - in ▁dog f ight ing ▁sp elled ▁the ▁end ▁for ▁the ▁special ized ▁Gr um man ▁F - 1 1 1 B , ▁which ▁was