I'm wondering if it would have been possible to have with the technology available at the time to have produced a VFX contender that could meet all the specs and avoid a swing-wing?
Swing wings often add excess weight which reduces the T/W ratio of the aircraft: Though their wings produce very high L/D ratios and allow lower fuel-fractions to do the job
(and saving weight there); a high fuel fraction means a greater spread in weight from takeoff to combat weight. This in turn allows a pretty high T/W ratio at combat weight
(I'm kind of surprised come to think of it that the USAF didn't factor that in when they designed long range escorts)Admittedly the F-14 did have impressive performance capability provided it was fitted with the intended engine it was supposed to have
- Almost as fast as a MiG-25, and almost as fast as the design limit for the F-15A (VMax off)
- Greater range, endurance and subsonic cruising radius on internal fuel with probably a greater load
- Superior intercept radius (supersonic out, go subsonic, possibly sit there 15 minutes; then cruise back subsonic) to the F-15 at some loads
- Superior instantaneous agility in pitch
- Sustained agility was superior at lower speeds and altitudes than the F-15, at supersonic speeds; the F-15 was superior at high subsonic speeds and at altitude (middle-speed range, and at altitude)
- Higher alpha capability
That engine was however cancelled. Still, the aircraft wasn't totally unimpressive.
Consider, however the following facts and knowledge that existed as of 1968
- Certain materials already existed when coupled with good engineering techniques could produce a remarkably strong aircraft that was still light (The F-8, for example was quite light, even more so than the F-100)
- Fly by wire coupled with stability augmentation did exist: The Canadians had already employed it back in the late 1950's with their CF-105 Arrow: This could increase cruise-efficiency and improve low speed handling characteristics so long as it works
- The knowledge of blending the wing and body together, as well as blending the wing-spars with the structural frames already existed and would allow more strength for the same weight
- Leading-root extensions were already employed on planes like the Saab J-35, and the F-5: Not only did it increase high alpha performance, sometimes directional characteristics; it also did something else -- they could be shaped so as to produce significant amounts of lift while supersonic mitigating the shift in the C/P
- Double-droop leading-edge flaps already existed: They were used on the XF8U-3 to allow improved low-speed handling and maneuverability; the Boeing 2707-100/-200 SST even used a droop on the leading-edge slat (it's like a slat with additional curve)
- Flap shrouds also existed: They were actually also proposed for the Boeing 2707-100 SST to effectively improve the double-slotted flaps they used
- Close-coupled canards also were used on the Saab J-37 Viggen (1967)
