The General Motors FM Wildcat was essentially the Grumman produced F4F Wildcat but built by General Motors. In total over 4,500 General Motors FM Wildcat aircraft were produced by the end
of August 1945, nearly two thirds of the total production run of Wildcats.
With Grumman working on their new fighter, the F6F Hellcat, but with demand for its predecessor, the F4F Wildcat,
still high, the decision was taken to outsource production of the aircraft. This led to a contract being agreed on the 18th April 1942 for 1,800 F4F Wildcats to be produced by General Motors, and these would be known as FM-1 or FM-2 Wildcats.
The 1st September 1942 saw the first FM-1 fly, although this had been produced from parts which Grumman had already manufactured. Powered by the 1,200-hp Pratt & Whitney R-1830-86 engine, the FM-1, originally called the Martlet
Mk V by the Fleet Air Arm, before being renamed the Wildcat Mk V, had a top speed of 318 mph, a range of 900 miles and a service ceiling of 35,000 ft. Armament was four 0.50-in machine-guns and either 500lb bombs or rocket
projectiles.
Development of the aircraft continued, and a pair of Grumman built XF4F-8s would provide the basis for the FM-2, named Wildcat Mk VI by the Fleet Air Arm. This new variant had its fin and rudder made taller and featured a
lighter airframe to help take-off performance. Powered by the 1,350-hp Wright R-1820-56 Cyclone engine, its top speed was 332 mph, range 900 miles with a service ceiling of 35,000 ft. Armament consisted of four 0.50-in
machine-guns and either 500lb bombs or rocket projectiles.
With a total of 4,777 aircraft being delivered by August 1945, when production ceased, it meant that over 7,500 Wildcats had been built by Grumman and General Motors Combined.
