High Quality Content by WIKIPEDIA articles! The Grumman F6F Hellcat was a carrier-based fighter aircraft initially conceived to replace the earlier F4F Wildcat in United States Navy (USN) service. Although the F6F resembled the Wildcat, it was a completely new design, powered by a 2,000 hp Pratt & Whitney R-2800, the same powerplant used for both the Navy`s earlier Chance Vought F4U Corsair and the Army Air Force`s Republic P-47 Thunderbolt fighters. Some military observers tagged the Hellcat as the "Wildcat`s big brother".