X-Plane 9.70+ Grumman F6F-5 Hellcat v1.0. The Grumman F6F Hellcat was a carrier-based fighter aircraft developed 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 2000 hp Pratt and Whitney R-2800. Some tagged it as the "Wildcat's big brother". The Hellcat and the Vought F4U Corsair were the primary USN fighters during the second half of World War II. By Fabrice Kauffmann.