F4F Wildcat / Joe FossGrumman F4F Wildcat airplane model. By the end of 1941, the Grumman F4F 3 and its variant, the F4F 3A, popularly known as "Wildcat," had replaced the F2A in most U. S. Navy and Marine Corps fighter squadrons. The F4F 4, a folding wing version, first flew in April 1941 and was introduced into service in early 1942. Influenced by British tactical concepts, it was equipped with six guns but carried less ammunition. Although the F4F 4 was heavier and not