Grumman F4F WildcatGrumman F4F Wildcat airplane model. By the end of 1941 the Grumman F4F 3 (and similar F4F 3A) fighters, which had received the popular name "Wildcat" a few months earlier, had replaced the F2A in most U. S. Navy and Marine Corps fighting squadrons. A folding wing version flew in April 1941 and entered service in early 1942 as the F4F 4. Prompted by British tactical concepts, it had six guns but less ammunition. The heavier F4F 4 was not as nimble nor