The original layout of this single-seat carrier-based fighter provided for the installation of four wing-mounted Westinghouse 19XB-2B (Navy J30) axial-flow jets. But this arrangement was abandoned in favour of one fuselage-mounted high-powered turbojet engine before prototype construction began, a change prompted by the successful tests conducted by the Navy in December 1946 with two imported Rolls-Royce Nene engines.
The first prototype XF9F-2 was powered by an imported Nene engine and flew for the first time on 24 November 1947. The second prototype was similarly fitted, but the third (the XF9F-3) had an Allison J33 engine. Production aircraft were divided between Nene and Allison-powered models, the former engines licence-built by Pratt & Whitney as J42s.
The first production F9F-2, powered by a 22.24kN J42-P-6, flew for the first time on 24 November 1948. The 20.46kN J33-A-8-powered prototype flew for the first time on 15 August 1948 and a total of 418 of both versions were built. However the F9F-2 proved to be the better version and the F9F-3s were re-engined to F9F-2 standard. The F9F-4 (73 of which were ordered originally) was powered by an Allison J33-A-16 engine, but none was completed and the contracts were combined with those for more than 580 27.80kN Pratt & Whitney J48-P-4/6A-engined F9F-5s (which flew for the first time on 21 December 1949). The F9F-5P was a photographic-reconnaissance version with a longer camera nose.
Panthers are remembered in US Navy history as their first jet fighter to be used in combat, introduced into the Korean War on 3 July 1950, as well as for recording a victory against an enemy jet aircraft, a MiG-15, on 9 November 1950.
