This is not the Grumman F12F:
![]()
It is the Grumman G118, proposed to the Navy in December 1955. The Navy rejected it because they didn't want a second development program of a fighter powered by two J79s (the McDonnell F4H was already under contract) but suggested that Grumman go back to the drawing board and propose a single-engine, Sparrow-missile armed fighter to compete with Vought's proposal for a Sparrow-armed "Super" F8U powered by the P&W J75. Grumman did but the Navy rejected it as well in favor of what became the F8U-3. Neither of the two Grumman proposals was ordered, much less received BuNos.
There was a Grumman F12F but it was a program to reengine the F11F with GE's J79. Grumman had proposed its G98J to the Navy in January 1955. The Navy prepared a purchase order and contract in August 1955 for two F12F prototypes, which were to be assigned BuNos 143401 and 143402. It's not clear that the contract was ever issued. In any event it was canceled in January 1956, probably due to the demonstrated performance of the Vought F8U-1 that first flew in March 1955. However, the Navy had contracted with Grumman in August 1955 to put the J79 in the last two F11Fs of the first production lot in parallel with this plan. These were designated F11F-1F.
This is the US Navy's F12F Characteristics Summary dated 15 August 1955. Although there is no drawing and it is somewhat bigger than the F11F, it is definitely smaller than the G118 and powered by a single J79 engine.
![]()
One or more aviation historians have inadvertently conflated the two programs and incorrectly concluded that the Navy contracted with Grumman for its twin-J79-powered G118 and designated it F12F. Another enthusiast even speculated that it was given the popular name Lion, which some have accepted as fact as well. It was not.
It is the Grumman G118, proposed to the Navy in December 1955. The Navy rejected it because they didn't want a second development program of a fighter powered by two J79s (the McDonnell F4H was already under contract) but suggested that Grumman go back to the drawing board and propose a single-engine, Sparrow-missile armed fighter to compete with Vought's proposal for a Sparrow-armed "Super" F8U powered by the P&W J75. Grumman did but the Navy rejected it as well in favor of what became the F8U-3. Neither of the two Grumman proposals was ordered, much less received BuNos.
There was a Grumman F12F but it was a program to reengine the F11F with GE's J79. Grumman had proposed its G98J to the Navy in January 1955. The Navy prepared a purchase order and contract in August 1955 for two F12F prototypes, which were to be assigned BuNos 143401 and 143402. It's not clear that the contract was ever issued. In any event it was canceled in January 1956, probably due to the demonstrated performance of the Vought F8U-1 that first flew in March 1955. However, the Navy had contracted with Grumman in August 1955 to put the J79 in the last two F11Fs of the first production lot in parallel with this plan. These were designated F11F-1F.
This is the US Navy's F12F Characteristics Summary dated 15 August 1955. Although there is no drawing and it is somewhat bigger than the F11F, it is definitely smaller than the G118 and powered by a single J79 engine.
