FM-2 from USS White Plains (CVE-66), June 24, 1944
As World War II progressed and the U.S. industrial war machine ramped up, Grumman shifted its focus to producing the F6F Hellcat, which led to some creative production arrangements. One such arrangement involved General Motors (GM), which had previously been known for building automobiles. Under government direction, GM repurposed its New Jersey plants to produce aircraft as part of the Eastern Aircraft Division. This division took over the production of the Wildcat and the Avenger torpedo bomber, allowing Grumman to concentrate on the Hellcat.
To distinguish between the aircraft produced by Grumman and those produced by GM’s Eastern Aircraft Division, the Wildcat’s designation changed from F4F to FM, and the Avenger’s designation changed from TBF to TBM for the GM-produced versions.
In mid-1942, production of the F4F-4 Wildcat transitioned to Eastern Aircraft, resulting in the FM-1. The FM-1 was nearly identical to the F4F-4, except that it had four .50 caliber machine guns instead of six, with 430 rounds per gun. The first FM-1 flew on August 31, 1942. Only 839 FM-1s were delivered before production shifted to the more advanced FM-2.
During this time, the U.S. Navy was also building a large number of escort carriers. These were smaller than fleet carriers, often converted from merchant ships, and were designed to provide air cover for convoys crossing the Atlantic and for ground forces in the Pacific. The escort carriers required a small, lightweight fighter, which led to the development of the FM-2.
The FM-2 was a significant improvement over its predecessors. It was 530 pounds lighter than the F4F-4 and equipped with a more powerful Wright R-1820-56 engine, which contributed to better performance at lower altitudes, where it was most needed for close air support and anti-submarine patrols. The lighter weight also improved the FM-2’s rate of climb and maneuverability, making it a better match for Japanese aircraft. The FM-2 could carry two 58-gallon external fuel tanks, and later models were equipped with racks for six five-inch rockets under the wings.
Visually, the FM-2 was distinguishable by its taller tail and large lateral exhausts located above the wings, which often streaked the sides of the fuselage. Unlike previous Wildcats, the FM-2 had no underwing oil coolers; instead, it used a single unit in the accessory compartment behind the engine. It was also fitted with a Curtiss Electric constant-speed propeller with wide chord blades.
The FM-2 was initially delivered in a tri-color scheme with non-specular blue on the upper surfaces, intermediate blue on the fuselage sides and vertical tail, and flat white on the undersides. Later, this was replaced by an overall gloss sea blue scheme. Interestingly, many FM-2s in this scheme featured insignia blue discs on the national insignia, a deviation from the usual practice of using only white stars and bars. In the Atlantic, FM-2s and other aircraft were often painted in a dark gull gray and white scheme, which was specifically designed for operations in that theater.