The Grumman F4F Wildcat was an American carrier-based fighter aircraft that began service with both the United States Navy and the British Royal Navy (as the Martlet) in 1940. First used in combat by the British in Europe, the Wildcat was the only effective fighter available to the United States Navy and Marine Corps in the Pacific Theater during the early part of World War II in 1941 and 1942. (Although the Brewster Buffalo was the Navy's first monoplane fighter, it proved disappointing in combat. It was withdrawn very early in the war and replaced by Wildcats as they became available.) With a top speed of 318 mph (512 km/h), the Wildcat was outperformed by the faster and more nimble 331 mph (533 km/h) Mitsubishi A6M Zero, but its ruggedness, coupled with tactics such as the Thach Weave, resulted in an air combat kill-to-loss ratio of 5.9:1 in 1942 and 6.9:1 for the entire war.
Lessons learned from the Wildcat were applied to the faster F6F Hellcat which could outperform the Zero on its own terms. The Wildcat continued to be built throughout the remainder of the war to serve on escort carriers, where larger and heavier fighters could not be used.
Even before the Wildcat had been purchased by US Navy, both the French Navy and the British Royal Navy's Fleet Air Arm (FAA) had ordered the Wildcat, with their own configurations..
The F4F Wildcat (known in British service as the Martlet) was taken on by the British Fleet Air Arm as part of an interim replacement for the Fairey Fulmar. The Fulmar was a two seat fighter with good range but at a performance disadvantage against single seater fighters; navalised Supermarine Spitfires were not being made available because of the greater need of the Royal Air Force. In the European theater, the Wildcat scored its first combat victory on Christmas Day 1940, when a land-based Martlet destroyed a Junkers Ju 88 bomber over the Scapa Flow naval base. This was the first combat victory by a US-built fighter in British service in World War II. The type also pioneered combat operations from the smaller escort carriers.
Six Martlets went to sea aboard the converted former German merchant vessel HMS Audacity in September 1941 and shot down several Luftwaffe Fw 200 Condor bombers during highly effective convoy escort operations. These were the first of many Wildcats to see shipboard combat.
The Fleet Air Arm (FAA) was later to abandon the practice of using its own unique names for US-provided aircraft in British naval service, and began to use the US Navy's aircraft names instead. In March 1945, Wildcats shot down four Messerschmitt Bf 109s over Norway, the FAA's last victory with a Wildcat