The Air Force's fiscal year 2018 budget request proposes a $4.5 billion increase to its Next-Generation Air Dominance program over the next five years -- potentially lending momentum to the service's lengthy effort to develop a follow-on to the F-22. The Air Force's FY-17 budget request called for about $20 million for NGAD and projected the effort would require only $12.8 million in FY-18 and FY-19. After signaling its intentions this spring to ramp up the effort through a $147...