Mig Victors: An Airbase In Japan -- A group of happy young F-84 Thunder jet pilots of the Fifth Air Force's 27th Fighter Escort Group smile broadly. They have just returned from the, greatest aerial battle of the Korean war, in which about 115 F-84 Thunder lets and F-86 Sabrejets of the Fifth Air Force tangled with 80 enemy MIC-15 type fighter which tried to intercept, a large formation of B-29 Superforts April 12 near the Yalu River in North Korea. During a fierce, high-altitude battle, more th