I'd like to throw out a few thoughts here,, for what they're worth. Since they touch on so many posts, and I'm not that good at splicing in multiple quotes, I'll just fire away:
1. F-15N operating an Essex (actually Ticonderoga class), while F-4 and F-14 couldn't, according to McAir. Well, of course they'd say that. In point of fact, the F-14 had a requirement to operate from those same carriers as well; that was the reason for its very low approach speed. However, that requirement was dropped because a) the Gov't failed to deliver an engine of the specified thrust and weight that made it feasible. b) It was clear in the early '70s that this class of carrier wasn't going to be with us for many more years anyway, so it wasn't worth the trouble and expense to have this capability. There was also the issue with both aircraft of the "Yellow Gear" on such a small carrier.
2. F401 dying through lack of funding. Technically correct, but there's more to it than that. The Air Force at this time was encountering developmental problems with the F100. Reliability in the test program was not up to snuff and the engine was not taking well to rapid changes in fuel flow. The F100 engine at this point in time was more critical to USAF than the F401 was to the Navy. Although the F401 was the engine around which the F-14 was designed and provided the thrust levels and sfc benefits to allow the F-14 to meet its design specifications, the Tomcat was flying successfully with the TF30. Without the F100, though, there could be no F-15. USAF knew that given enough time they would solve the early F100 problems. In fact, they eventually did in the next decade (partly by derating the engine), but at this juncture it didn't look like Congress was going to give them the necessary time. One of the most critical tests was the 150 hour run, wherein an F100 would have to run for 150 hours without failing. Congress had made it clear that without passing this test funding for the F100 would disappear, and the Eagle would remain grounded. Published reports at the time were somewhat confusing about the definitive 150 qualification test. According to some reports, on the critical test the engine was closely monitored and if certain key components appeared that they were about to fail, the test was suspended, the component replaced, and then continued. The F100 engine passed the test. Once the F100 passed the 150 hour qualification test the Air Force was no longer responsible for reliability and endurance improvements in the common core. At this point the Navy was on its own, and had to accept the core in its current state. Any desired core improvements would have to be funded solely by the Navy. The Navy took a look at what it would cost to bring the core up to an acceptable level of reliability and performance to bring the F401 into service and decided it just wasn't worth it, and so abandoned the engine in April, 1974. It wasn't until the arrival of the F110 that the Tomcat got the engine around which the plane had been designed. It has also been said that it wasn't until the arrival of the F110 that Pratt got serious about improving the F100's reliability and performance.
3. F-15N vs F-14 wing loading. It appears when deriving those numbers, you used the figure of 565 ft2 for the lifting area of the Tomcat. This ignores the entire tunnel area, which is a lifting body that adds 443 ft2 once the wings sweep. Using the full lifting area would give a ratio of 68, not 122 for the F-14 vs 94 for the F-15. This is one of the reasons that an F-14 at comparable T/W ratios outturned the F-15 (unless the TF30s were acting up in the F-14, unless the F100s were acting up in the F-15).
4. F-15 doing a loop at 150 knots IAS. Yes, it probably can, under the right conditions and at a safe altitude, but keep in mind that going up it’s under full a/b, not a normal condition on approach, and on the other half it’s going down rapidly, also something you probably wouldn’t want to do with the ocean filling your windscreen. The ability to do this would really have no relevance to landing on a carrier, as would a stalling speed that’s partly achievable due to downward thrust at extreme AoAs.
5. F-15N itself. Without massively redoing the wing and control surfaces I would find it hard to believe that the -15N would have an approach speed of 120 knots. Keep in mind the even the “light” F/A-18A, which was designed to be carrier compatible from the get-go can’t do that. Also, you have to keep the nose where you can see the MLS and deck. Lots of a/c can fly really slow if you point th nose at the stars. F-14 is something like 45 knots. Hey, the Mig-29 and SU-27 can do zero! In any case, the original impetus for the -15N was a push by McAir to try and sell more of their planes (can’t blame them). The “flyoff” idea was never serious, IMHO, but a way to placate Congress. It would cost a fortune to do, and while valuable would only mostly tell you what you already knew. ,Just assume that both planes would do what their manufacturers promised. What do you learn? Actually, there was sort of a “flyoff” once-the second Iranian fighter order (under the Shah). Both the F-15 and F-14 were involved. The F-15 flew first and gave its usual eye-watering performance and there were some really neat shots of it making its really tight turns as it headed back onto the base for the next maneuver. The F-14 flew next, and essentially matched the Eagle’s performance (with couple of extras thrown in), with one notable difference: it was able to do all that within the airfield’s perimeter. This was a contributing, but not the only factor in why Iran bought the F-14 on both buys. As an aside, one of the big reasons there weren’t more F-14 export orders is that except for Iran, the US wouldn’t allow the aircraft to be exported (although they probably would have made an exception of the UK).
In any case, in order for the F-15N to be a viable concept the Navy would have to relax its requirements to whatever the -15N was capable of (shades of the Hornet!). Range and endurance, sensor performance, etc. . Because of the funding issues (mostly caused by the Gov’t) the F-15N was at least considered, but what really doomed the idea was that it would have cost more to “navalize” and equip the Eagle for the Navy than the amount of the funding issues with the F-14, and you would have ended up with a less capable, less versatile aircraft. No reflection on the Eagle, just that’s why the Tomcat cost more (along with production rates). Also, there was really no need to take on a new aircraft with a more expensive, unreliable engine when the Navy already had a less-expensive unreliable engine of its own.
Because of this and due to massive and effective lobbying by the light fighter lobby, it was decided to develop a “Naval Air Combat Fighter”, as the Air Force was doing because of pressure over the cost of the F-15. Not too far into that, Congress weighed in and decreed that the NACF would be required to be a derivative of the USAF’s ACF.
