WI: Air Force F-14 and Navy F-15

What if the USN had gone with something similar to the F-15 and the USAF had gone with something similar to the F-14? The F-15 is a better universal airframe than the Hornet because of its size and performance envelope, and the F-14 is a potent fighter/interceptor which has better performance in some areas (maneuverability is rumored to be quite good). The F-15 is also a more simple design with a higher thrust to weight ratio (especially in early variants), which would allow it to operate from a wider variety of ships and better support Marine operations. There was a proposed F-15 variant with the Phoenix missile system, so the USN wouldn't have to give that up on interceptor aircraft. Using different variants with largely similar subsystems and airframe design and exchangeable FAST packs (historically only fuel packs were procured, but water injection, electronic warfare, reconnaissance packs, and weapons packs were also pdoposed) the Navy could replace several aircraft with F-15 derivatives and simplify logistics, important on an aircraft carrier.

The USAF could use more dedicated aircraft to take advantage of land operations, having the F-14 as a fighter/interceptor, the F-111 for strike, and the F-16 or another LWF design for light strike and visual range dogfighting. The F-14 and F-111 both share engines, and if the USAF decides to it can adopt F-16 engines for them. The USAF could procure a lightened single seat design without Phoenix.

This wouldn't be as unusual as it appears, as both services examined a variety of options. There were fixed wing designs examined during F-14 development that looked like the F-15, and the F-15 had its origins in swing wing designs that resembled the F-14. So, what if things had gone ddifferently, and they had ended up with the other design?

Delta Force said:

What if the USN had gone with something similar to the F-15 and the USAF had gone with something similar to the F-14? The F-15 is a better universal airframe than the Hornet because of its size and performance envelope, and the F-14 is a potent fighter/interceptor which has better performance in some areas (maneuverability is rumored to be quite good). The F-15 is also a more simple design with a higher thrust to weight ratio (especially in early variants), which would allow it to operate from a wider variety of ships and better support Marine operations. There was a proposed F-15 variant with the Phoenix missile system, so the USN wouldn't have to give that up on interceptor aircraft. Using different variants with largely similar subsystems and airframe design and exchangeable FAST packs (historically only fuel packs were procured, but water injection, electronic warfare, reconnaissance packs, and weapons packs were also pdoposed) the Navy could replace several aircraft with F-15 derivatives and simplify logistics, important on an aircraft carrier.

The USAF could use more dedicated aircraft to take advantage of land operations, having the F-14 as a fighter/interceptor, the F-111 for strike, and the F-16 or another LWF design for light strike and visual range dogfighting. The F-14 and F-111 both share engines, and if the USAF decides to it can adopt F-16 engines for them. The USAF could procure a lightened single seat design without Phoenix.

This wouldn't be as unusual as it appears, as both services examined a variety of options. There were fixed wing designs examined during F-14 development that looked like the F-15, and the F-15 had its origins in swing wing designs that resembled the F-14. So, what if things had gone ddifferently, and they had ended up with the other design?

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I think it is more likely that the F14 could have been cancelled due to the serious engine problems in the early versions and both sides wind up with the F15. The USAF would have loved it because they would see it as turnabout for having to buy the Navy's F4 during the 1960s and 70s.

The problem with the USAF F14 is that until they did the Air Defense Command upgrade program, the USAF was looking for more of a fighter that could dogfight rather than an interceptor like the F14, which was optimized to kill bombers with Phoenix missiles.

Trevayne said:

I think it is more likely that the F14 could have been cancelled due to the serious engine problems in the early versions and both sides wind up with the F15. The USAF would have loved it because they would see it as turnabout for having to buy the Navy's F4 during the 1960s and 70s.

The problem with the USAF F14 is that until they did the Air Defense Command upgrade program, the USAF was looking for more of a fighter that could dogfight rather than an interceptor like the F14, which was optimized to kill bombers with Phoenix missiles.

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As I have said in the other F-15 thread there is no way the F-15 as we know it had a chance of becoming a carrier based fighter. It just wasn't designed to be subjected to the pounding a carrier fighter gets. And by the time it was redesigned to handle those stresses it wouldn't be the F-15. And the F-15 had it's own engine problems. The F-16 was subject to the same problems (It used the same F-100 engine) and they were grounded for weeks since they were single engine. I'm not sure if even the twin engine F-15 would have been grounded if it was flying over the ocean where there weren't alternate landing sites.

The Air Defense Command was on it's way out in the Air Force by the time the F-14 was developed. The manned bomber was no longer a major threat to the continental U.S. Until the Anti Satellite capability was rolled out (and later the September 11 environment) the mission of the 'Alert Birds' was dieing. and and neither of those missions really calls for the multi target capabilities of the F-14.

I'm thinking more in terms of the USAF program developing a variable geometry fighter quite similar to the OTL F-14. Historically, some of the designs explored on the way to the F-15 were quite similar to the F-14 in design. The F-15 was originally designed to fight the MiG-23 and earlier designs, but was revised to be even more manuverable after intelligence sources mistakenly identified the MiG-25 as being designed for dogfighting instead of as being a heavy high speed interceptor. Given that the Soviets were actually building aircraft for BVR combat instead of manuverability, an F-14 type aircraft could have countered those designs. It could have been procured in different variants, similar to the Panavia Tornado. Some would be more interceptor oriented, while the majority would be more fighter oriented.

The Navy could go for an F-15 type fixed wing aircraft program to reduce airframe development costs and allow a single aircraft family to fill the fleet air defense, light attack, and multirole designs with a single design. That would significantly reduce the very complex logistical situation found in Navy aviation at the time, making even many major airframe components similar between aircraft types. An F-15 type design wouldn't perform like the F-15 once navalized, but it would have higher performance and potential than the Hornet, which is limited even in the Super Hornet development.

Delta force makesa good point about the procurement decisions that could happen if the F14 was the chosen aircraft , whether the differences between modelswould be as profound as thedifferences between IDS and ADV with thetornado ( the ADV is several feet longer overall to allow the carriage of 4 semi recessed radar guiaded missles - originally sky flash as well as needing a longer , differently shaped nose radmoe for the Foxhunter radar ( when it was finally ready as opposed to the 'blue circle' equipped early F2s)).

the F14 and the Tornado ADV share design concpets and assumptions as a long range /BVR interceptor capable of killing Bears etc ...

The Grumman Design 303 and McDonnell Douglas Model 199 show the evolution of the USN and USAF contracts, respectively. I can't find images of the variable geometry aircraft that led to the F-15 (although in 1968 there were proposals for 60,000 pound variable geometry designs), but the F-14 development process is well documented. Images are from this site.

Grumman Design 303C



Grumman Design 303D



Grumman Design 303E (developed into F-14, improvement on Design 303-60, Design 303A, and Design 303B)



Grumman Design 303F (similar to the F-15)



Grumman Design 303G (cutdown Design 303E without Phoenix)

I've got 1,200 hours in the Mud Hen (F-15E) and while the Tomcat was a fantastic aircraft, it's not an -15C...or E.

I just noticed the wing area on Design 303F. Since the Navy had strict weight requirements, that means the design would probably have weighed around as much as the F-14. 745 square feet of wing with a loaded weight of 61,000 pounds gives a wing loading of only 81.88 pounds per square feet. That's much closer to F-15 levels.

The interesting thing about the F-14 and F-15 saga is that around 1968 the USAF was concerned that they would have to adopt the USN design because it was more developed than their effort, and around 1972 it was the other way around and the USN was concerned it would have to adopt the USAF design.

I wonder how a joint procurement program would have gone if Design 303F had been procured, or if the USN had selected Design 303E (as historical) and the USAF had selected Design 303G.

Better scenario

F-14 for USAF and USN!
And with twist all aircraft are the same. So in case of war USN and USAF can share aircraft (USAF does train at CVs).
Soon Super tomcat follows...

Is it pure fantasy?

I'm curious as to why the F-15 wasn't considered for the Navy?

Panica said:

Is it pure fantasy?

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Given the interservice rivalries and the frankly astronomical costs involved in training almost the entire USAF fighter community to be naval aviators, yes.

Plus, the early F-14 isn't exactly suited for the majority of roles the F-15 was expected to undertake, and vice versa. The Tomcat would have been absolutely perfect for ADCOM though, as a replacement for their F-106s.


Speaking of Tomcat upgrades though, I wonder if the IRIAF did ever re-engine their Tomcats. The Saturn AL-31 would be the perfect engine for the job.

Cook said:

I'm curious as to why the F-15 wasn't considered for the Navy?

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Timing, interservice rivalries and very different operational goals. The F-15 was and still is a counter air fighter mostly, while the F-14 was more focused on being an interceptor, and was pretty much built around the AN/AWG-9 and AIM-54 Phoenix combo, and the associated computers.

The F-15, aside from being designed for NAVAIR's one true enemy, frankly couldn't be expected to cart the Tomcat's electronics suite around.

Panica said:

F-14 for USAF and USN!
And with twist all aircraft are the same. So in case of war USN and USAF can share aircraft (USAF does train at CVs).
Soon Super tomcat follows...

Is it pure fantasy?

Click to expand...

The aircraft would likely be quite similar, but not the same. The Air Force and Navy F-4 Phantoms had some differences between them, mainly related to the landing gear, tires, and carrier operations equipment. Avionics would likely also be different because the two services had different force doctrine and operational requirements. The USN favored IR missiles such as the AIM-9 Sidewinder and very long range missiles such as the Phoenix for fleet defense, while the USAF favored radar guided missiles such as the AIM-7 Sparrow. But the basic airframes and likely the engines would be very similar and have significant compatibility.

Also, it would be expensive to train Air Force pilots to operate from aircraft carriers, and not really required. The Marines augment the USN and both fly from carriers and operate from land.

Cook said:

I'm curious as to why the F-15 wasn't considered for the Navy?

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Actually, it was around 1972. The F-14 was running into development problems and was at risk of being canceled. McDonnell Douglas began looking into a navalized variant of the F-15. In the end the Shah of Imperial Iran was interested in the F-14 and purchased eighty of them for the Imperial Iranian Air Force. If Iran had purchased the F-15 instead that certainly wouldn't have helped the F-14.

Here are some pictures of the proposal. Keep in mind there was also an F-15N without the Phoenix missile system that was proposed as well.

Training Air Force drivers to operate from aircraft carriers? That's about as ASB a statement as I've seen!

mikewrites said:

Training Air Force drivers to operate from aircraft carriers? That's about as ASB a statement as I've seen!

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Well benefits could be great! Problem with F-35 or F-4 is they have different versions so benefits of scale are not that big as they could be.

Disadvantage for USAF would be little-bit heavier aircraft
On + side you would get more corrosion resistant airframe with sturdy landing gear (with ability to use more basing options) + lower cost due to advantages of bigger production numbers.



If aircraft were to be absolutely same you would have nice production numbers.
Problem is that training on CVs is not what USAF wants to do.


You can have mock up CV (Via janes - picture of PLA Navy mock up ship (US navy has one too))



Say hi to Super Tomcat:

NothingNow said:

frankly couldn't be expected to cart the Tomcat's electronics suite around.

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Why is that? The airframes seem to be of a similar volume.

Cook said:

Why is that? The airframes seem to be of a similar volume.

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The F-14 was designed around the Phoenix missile system. The AWG-9 radar weighs 1,300 pounds, and a load of six AIM-54 Phoenix missiles and launch rails weighs 8,000 pounds (twice as much as an AIM-7 Sparrow load). Also, I can't find the time frame for this, but the Phoenix cost $500,000 each, while a Sparrow costs only $125,000 each today. The intended roles are also different. Phoenix is intended for targeting cruise missiles and bombers, while Sparrow is intended for use in dogfighting. An AIM-54 probably wouldn't be useful in a dogfight, and even if it was a cheaper missile could do the job.

The F-15 could be modified to carry the system, but ideally you would only have Phoenix equipment on aircraft that would be used as interceptors due to the weight and cost penalty of the equipment.

Some interesting background on the F-14. Some of it paraphrased from here.

Originally, the F-14A was planned to be a limited production model, helping to develop the aircraft while the Pratt & Whitney F401 engine (a Navy variant of the USAF F100) was developed. The F-14B would be the first production variant, featuring the F401 and other improvements. However, the USAF accepted delivery of the F100 at a lower reliability level than the Navy was willing to accept, and they didn't have enough funding to bring the F401 up to where they wanted it to be. The Navy thus retained the TF30 engine, which was underpowered and brought problems of its own, such as low responsiveness, sensitivity, etc. Sometimes the TF30 would even explode. The first female naval aviator in the USN was killed due to a TF30 failure.

The result of being stuck with the TF30 was that the F-14 had much lower performance than was originally planned, with the F-14A development model becoming the production model, and the most numerous production model at that. Later developments helped to improve performance, and from a power and maneuverability perspective the F-14D is where the F-14B was planned to be. The F-14D introduced a new maneuverability system that would have been equipped to earlier models, but that was delayed because the TF30 was notoriously intolerant of airflow changes in both the F-14 and F-111 (the F-111 is another aircraft that suffered and was likely retired early due to TF30 related problems). The system made the F-14 quite maneuverable compared with other aircraft, and the most maneuverable in the supersonic flight envelope.

There were also glove vanes equipped for improved maneuverability, but ironically they were only equipped to earlier production aircraft that couldn't take full advantage of them. They were later disabled and/or omitted from aircraft because pilots were manually deploying them to increase maneuverability and stressing them too much.

Now for the more advanced variants of the F-14 that were proposed. Paraphrased from here.

Quickstrike/Block IV would have taken advantage of the similarity between the APG-70 radar used on the F-15E Strike and the APG-71 radar used on the F-14D. Software modes would have been carried over from the Strike Eagle and implemented on the Tomcat, as well as radar search modes. Targeting pods from existing designs would have been implemented as well. It would have given the F-14D capabilities on par with the Strike Eagle.

The Super Tomcat 21 (ST-21) and Attack Super Tomcat 21 (AST-21) would have featured more substantial changes relative to the Block IV upgrade. The General Electric F110-429 would have been equipped. Flaps and wings would have been revised, and the area where the wing gloves used to be would be revised to restore that performance and allow 2,000 pounds of additional fuel to be carried there. Approach speed would also be reduced, and the bringback capability would be brought up to 16,000 pounds instead of 9,000 pounds. That's a major improvement, because originally the Tomcat was incapable of bringing an entire load of AIM-54 Phoenix missiles back to the carrier because the missiles and their launchers weighed a total of 8,000 pounds.

ASF-14 was an even more ambitious program than STS-21/AST-21 proposed during the Naval Advanced Tactical Fighter Program (better known as the Navy F-22/F-23 program), which would have given the Tomcat 3D thrust vectoring and different wings. Unlike Block IV or STS-21/AST-21, previous production aircraft could not be upgraded to ASF-14 standards.

Here's a graph Grumman made that shows the relationship of the aircraft to each other.

How well would a navalized F-15 perform from an aircraft carrier akin to the Aircraft Carrier Medium or CVA-01? What about smaller ships such as the Sea Control Ship, Invincible class, or even retrofitted Essex class ships? Obviously the ships would be equipped with ski jumps as required.

The canard and thrust vectoring equipped F-15 ACTIVE saw a takeoff distance reduction of 25%, although it was based on the F-15C/D. If something similar was done with an aircraft that was navalized and equipped with higher thrust engines such as those on the F-15E, could a similar reduction have been expected? The F-15E is supposed to be capable of taking off in under 1,000 feet or so, so it seems ski-jump operations would be quite feasible from a thrust to weight and takeoff distance perspective.