Old planes/designs with new technology: F-4 Phantom II and no F-15/F14/FA18

[gjs238]

Old planes/designs with new technology.
The thread of the Superhornet replacement got me thinking about this.

Could the F-4, with appropriate updates, have provided necessary performance and carried US Air Force/Navy/Marine requirements forward through today without the need of the F-15, F-14, F-18?

I'm not including the F-16 here because that seems more comparable to the F-5.

 

[Crimea_River]

Without a complete redesign, I'm sure the F-4 would have never matched the maneouverability of the later birds you mention.

 

[FLYBOYJ]

Could the F-4, with appropriate updates, have provided necessary performance and carried US Air Force/Navy/Marine requirements forward through today without the need of the F-15, F-14, F-18?

No - the IDF did do some improvments to their F-4s but was still light years behind the mentioned aircraft, especially the F-15.

 

[syscom3]

Didnt the Germans upgrade their F4's to keep pace with modern designs?

 

[FLYBOYJ]

Didnt the Germans upgrade their F4's to keep pace with modern designs?

They did, but you're not going to be able to get an F-4 anywhere close to an F-15 in performance. Avionics, nav equipment, all good, but still behind the newer aircraft.

 

[Colin1]

The F-4 wouldn't have gotten to altitude to counter the MiG-25 anywhere near as fast as the F-15 did, I believe the MiG-25 was a primary driver for the F-15 program - before they realised what a barge the MiG-25 was.

I vaguely remember reading an article about experienced Vietnam-blooded F-4 jocks tangling with the new-in-service F-14 in mock knife-fights and coming off second best but I wouldn't know if that were true or just sales talk. I doubt it would win BVR either.

You've made me wonder if the F-4, with a similar avionics suite, wouldn't be as good as the Tornado in the mud-mover role.

 

[FLYBOYJ]

The F-4 wouldn't have gotten to altitude to counter the MiG-25 anywhere near as fast as the F-15 did, I believe the MiG-25 was a primary driver for the F-15 program - before they realised what a barge the MiG-25 was.

I vaguely remember reading an article about experienced Vietnam-blooded F-4 jocks tangling with the new-in-service F-14 in mock knife-fights and coming off second best but I wouldn't know if that were true or just sales talk. It doubt it would win BVR either.

Correct on all counts. My father in law had a chance to fly F-4s and F-15s and he said there was no comparison.

You've made me wonder if the F-4, with a similar avionics suite, wouldn't be as good as the Tornado in the mud-mover role.

It might be - the Rhino was able to carry a lot of weight - remember it made a good Wild Weasel aircraft.

BTW, CF-5As had F-18 avionic suites in their last years in service.

 

[DerAdlerIstGelandet]

Didnt the Germans upgrade their F4's to keep pace with modern designs?

Later German F-4s were mostly used in Recon roles and home defense as well as Wild Weasel. They were not used in that sense as a front line fighter.

Only a few years ago I had one buzz over us when flying around. He passed over our helicopter by maybe 1000 ft. Was pretty neat actually. I believe there believe there a still 60 or so in service with JG 71.

 

[Messy1]

I don't think other than avionics upgrades that there would be much you could do to make the F4 keep up with the current generation, or even the generation before's planes. Without it's big engines for it's speed, the F4 was not known for it's maneuverability I do not think.

 

[vanir]

My two cents,

we shouldn't be comparing the F-4 to the F-15 if you're talking about cancelling the F-15 project in favour of an updated F-4 to carry the USAF through the 1970's.

We should be comparing it to its overseas contemporaries. These would be the MiG-23 primarily. And it's about even on overall performance, the MiG is much faster and more nimble (the Flogger-G can out-accelerate an F-16 but that isn't available until the late 70's), but the Phantom is more robust and a better weapons platform. Also consider that by the mid-70's an F-4 fleet as the primary fighter type would have the ICE stats of an AN/APG-65 and by 1980 the early AMRAAMs.

But you couldn't cancell either the F-16 or F/A-18 and between them they'd replace Phantoms in front line service by 1980. Those two modern fighters are perfectly cost effective anyway.
It was really the F-15 that was a rushed development, hence ridiculously expensive and a little ahead of its time in terms of complexity. It cost just about as much to put in service as it did to develop and put into production, then as much again to maintain.

But it did deliver the goods, not really very cost effectively at all, but they were there. You can't compare an F-4 to an F-15 any sooner than you could a MiG-23M (Flogger-B), but you can compare an F-4 to a MiG-23 no prob.

 

[gjs238]

Question: Weren't both aircraft ~similiar empty weight?
(F-4 F-15 that is)

 

[Colin1]

Question: Weren't both aircraft ~similiar empty weight?
(F-4 F-15 that is)

Possibly
just not quite the same thrust being applied to both

late-mark J-79: approx 18,500lbf with afterburner (approx 12,000lbf dry)
early-mark TF-100: approx 29,000lbf with afterburner (approx 18,000lbf dry)

 

[vanir]

Plus engine dynamics are pretty different between the old turbojet and newer turbofan, specific thrust, frontal thrust, static thrust, the turbofan is much more fuel efficient and has several performance enhancing benefits, not the least being less tendency to overspeed.

The Brits put Rolls Royce turbofans in some of their Phantoms and whilst top speed wasn't improved because the intakes had to be widened, the overall mid range performance, fuel consumption and low speed handling were much improved.
One of the main restrictions of Phantom level speed is fuel consumption, in service conditions it was an impressive thing to manage 2 Mach in one, most wouldn't see more than 1.4-1.6 unless specially prepared for a speed run, as stated by pilots.
But this holds true for most jets, when they say "Mach 2.3 top speed" what they really mean is that it can carry a bigger load to about 1.5 Mach than other contemporaries which have a top speed listed as "Mach 1.8"
Maximum level speed with most supersonic fighters is really a measure of load bearing and altitude performance and not actual speeds ever achieved under service conditions.

There are some exceptions, notably the MiG-25 (it's Mach 2.8 is demonstrated with a 2 ton external load in a serially produced example right off the line, hella impressive).

With F-4 manoeuvrability, against the MiG-21 which was much, much lighter and had great thrust/weight and thrust/drag (meaning both excellent acceleration and top speed, as well as spritely manoeuvrability), well the F-4 was considered especially good in early Vietnam encounters with the Fishbed because it has plenty of excess thrust at subsonic speeds and that MiG didn't have boosted controls where the F-4 did. Also a help was the dedicated weapon systems operator (WSO), who acted as both an extra pair of eyes in an era of warplanes which have a poor field of view, and a dedicated brain to operate weapons systems in an era of warplanes where avionics were fairly rudimentary in terms of artificial intelligence.

The way it worked out was the Phantom had the advantage at low altitude where transonic performance, excess thrust and additional operating functions really came into play. But the MiG had the advantage at high altitudes where you could be more single minded, outright speed performance and supersonic acceleration was important, and high-g manoeuvres were prohibited by speed. At medium altitude they were about even.

The Flogger however introduced more performance to the MiG, it had comparable excess thrust in subsonic manoeuvres and boosted controls, but it still falls down on functionality and as a weapons platform. The radar on the Flogger for example is a very simple unit, barely capable of true lookdown/shootdown and it was the Soviet's first attempt at doppler so it was probably pretty easy to break a lock with, also of course analogue and not digital. Its display didn't even have a CRT screen, it just projected syntax on the HUD and all told is a very basic unit. By 1975 the Soviets installed an IRST under the nose as a more reliable option for close combat.

Really, get an F-4E and pop an AN/APG-65 in it and smack in the middle of 1976 it'll go toe to toe with Floggers and kick butt in altitude BVR. Get down low and hell, you've got F-16's by then and the Flogger doesn't have a chance (near the deck). You don't need an F-15, that's the argument. Just not needed.

 

[Glider]

The one plane that could be updated (in theory) is the Tornado. The original design of the Typhoon engine was such that they could be installed in the Tornado. Put that to the extended fusulage with the extra fuel tank as fitted in the Tornado fighter versions and that would be quite an improvement in range / payload. I don't know how the engines changed over the years but even if they did fit the airframe would not get the best of the old technology plus the aircraft are getting old and maintaining the Tornado must be a major problem.
Obviously I am talking about upgrading the Tornado in the strike role, it was never a dogfighter.

The F15 was needed and results have proven this. The F16 in its first few versions was a dogfighter pure and simple and it didn't carry Sparrow missiles, just sidewinder. Without the F15 the USSR would have the advantage in long range combat and wouldn't be nearly as worried as the West about shooting down some of their own aircraft by mistake. The F4 was better than the Mig 23 but would not dominate it in the manner of the F15 plus the F4 couldn't allow itself to get sucked into a dogfight with the later versions of the Mig 21. The much larger USSR airforces would soon overwhelm the few F4 available.

 

[gjs238]

Let's hotrod the F-4, just for fun.
Get F-15 engines avionics in there.
Replace components with carbon fiber where possible.
Streamlined gun/cannon installation.
Revised air intakes.
Etc, etc., etc.

Thrust vectoring (?!)

It may end up costing more than a F-15, but would be interesting.

 

[Colin1]

Thrust vectoring (?!)

I'm a bit off base with the modern stuff
but I don't think thrust vectoring is something you just tag on the end of the aircraft, I think there is significantly more of the airframe involved than meets the eye. Could be wrong on that.

I think the F-4 tail unit would interfere with the vectoring anyway.

 

[Messy1]

I do not think you would get much bang for your buck hot rodding the F4. I was always under hte impression that it was not known as a aerodynamic masterpiece, basically was a flying brick or sled with really big engines.

 

[vanir]

I don't think results have proven the F-15 was needed at all. It's only combat prior to the US entering the Gulf was in Israeli hands where its glaring fault, that its design technology was ahead of the weapons technology to support it was prevalent. The Israelis wound up using them just like the US used the F-4 in Vietnam because of the shocking poor performance of 70's gen sparrows and sidewinders (the reason the Israelis developed the Shafir which is a generation ahead of the Sidewinder like the Archer or that South African missile). Actual combat reports in encounters with MiGs involved firing off all your missiles at once trying to hit one target and frequently missing, then getting a gun kill on a Fishbed through sustained manoeuvres, in these cases the performance of an F-4E would be just about the same, the main factors here being excess thrust and boosted controls.
The Sidewinder of the period had only just overcome the tactic of using g-manoeuvres to break its lock, but it still liked clouds and random heat sources. Sparrows were still just about useless, scoring maybe 1 in 3 shots fired and half the time just plain going ballistic after launch.

The Israelis did like the Eagle because of its terrific all round performance, they were used to dogfighters like the Mirage and it still had the weapons and intercept qualities of a Phantom with a newer tech avionics fit and especially its powerful radar. But those crappy era weapons ca.1978 still meant basically you saw the enemy well far away but still had to close to the same type of combat you'd be in using a Phantom or a Mirage anyway, because the weapons tech couldn't keep up with the plane tech. The Israelis jokingly referred to it as "the flying SAM site" because you had this powerful radar, waited for the enemy to finally close to combat range, then fired a whole lot of missiles, nevertheless the name isn't all that affectionate since the Israelis respect gun kills and dogfighting over any other aerial combat (mostly because guns don't fail on you). Upon closing to combat range Israeli pilots say they routinely ignore everything going on inside the cockpit with the avionics anyway, which is understandable considering the poor reliability of pre-80's-digital era.

The Eagle was like a glimpse into the future, a very, very, very expensive one. One should recall it was a knee jerk reaction to unreasonable paranoia about the Foxbat. You could've put the Eagle in production five years later and saved a bundle, but my point is it was still not strictly needed at all. It didn't actually serve any physical purpose which couldn't have been handled just fine without it, at a savings of several thousand million dollars, quite simply the United States would've been a wealthier country without it, you might've had free universal healthcare in 1976.

The F-16A was placed in service in 1980 and if I'm reading my Janes right in 1981 (block 5) it had Sparrow capability and a couple of other improvements (databuses and the like). The AN/APG-66 was pretty good with digital multimode, pulse-doppler and angle track, it was well ahead of anything in the Soviet arsenal before the Foxhound.


There's a couple of things to consider with the "fantastic Eagle performance" in that some of it, a good part of it is illusory because we're incorrectly comparing a 4th warplane with 3rd gen warplanes on that score.

As mentioned firstly weapons tech wasn't really up to 4th gen standard in the 70's, 4th gen is an 80's thing. It's like having a great new assault rifle with only black powder and ball to load it with.

Its engineering requirements, whilst achieved under test conditions are only partly achieved in service trim. First point is the 1.8 Mach speed restriction under normal combat conditions. There's an engine management system override switch inside the cockpit which was used to achieve its design requirements of a 2.5 Mach top speed (clean and specially prepared), but if used once the engines require a full tear down maintenance immediately upon landing.
Its other requirements were based on Vietnam experience in Phantoms, where it was found they manoeuvred well compared to MiGs at low altitude because of excess thrust and twin engine reliability, so improving on this theme of dogfight capability was listed. Borrowing industrial technologies from the blown out Valkyrie project were used for this. And of course a gun was mandatory.
The other requirement was extended ferry range for European deployment, achieved by aerial refuelling, external tankage and stripping (combat fit is carried in an escorting KC tanker's cargo hold). Unrefuelled range in combat trim isn't all that spectacular.

So it has great 4th gen (ie. honeycomb, body lift, good avionics fit) performance both in dogfight at low alt and BVR or intercept performance. But we're still comparing it to 3rd gen warplanes which is all wrong.
The thing to keep in mind is in the common 4th gen combat environment the Eagle can't dogfight on equal terms with an F-16, Hornet or a Fulcrum at low altitude. No way. I mean you can still win and it comes down to pilot skill, but just on the face of it these lightweight, dogfight specialised 4th gens have the standing advantages of sheer thrust/weight, specific thrust/altitude ("spooling" if you like), nimbleness, very high g-capability (the F-16 and MiG-29 were both specifically designed for 12+g without breaking although a pilot isn't supposed to exceed 9g if he wants to stay conscious and external stores can restrict it further depending what is carried).

So take the Eagle into an environment of technological parity, which is to say the period where its vision is kept up with by industrial tech commonality, and it's just like the Phantom was for a 3rd gen fighter, a heavy weapons platform designed for medium altitude BVR and sustained air superiority rather than agile low alt dogfights against lightweight 4th gen contemporaries like the F-16 and Fulcrum. But even so it can do dogfights pretty damn well. This was the same story for the Phantom up against Fishbeds, can do it but if you had the chance a medium alt missile kill was a safer bet if the missiles actually tracked for a change, and sustained transonic manoeuvres were the preferred mode of close combat (avoiding the benefits of a lightweight fighter).

The Eagle was a step ahead only because it was rushing something everybody was headed towards, at terrific cost, for an advantage that was both unnecessary and short lived.
In 1975 a force of Phantoms and F-5's are going to be perfectly contemporary against any Soviet threat. The Eagle had no advantages over the Foxbat from the Phantom (another conversation but my sources are Israeli combat records of Eagles versus Foxbats, mostly they all fired off all their missiles at each other without hits and then the Foxbats disengaged at a whim and were uncatchable, and Israelis have been known to chase enemy MiGs all the way to Egypt and get turned back by AAA over their home bases, if they could any way have caught a Foxbat in an Eagle, they would've).

Then in 1981 a force of Block 5 F-16A's and F/A-18 Hornets are already replacing the Phantoms, which is timely and still gets 4th gen fighters on the front line a full five years ahead of the Russians.
The only thing you're missing is a parity with the Flanker entering service ca.1990 but you don't have that with the Eagle anyway (it's often referred to as a 4.5 gen even with analogue FBW). Flankers retain more of their design requirements in full service trim than Eagles do and have other benefits (STOL, low maintenance and rough field operation). But then again Flankers are made almost entirely out of titanium (brittle but very, very light for their size, fit and loadbearing).

The Eagle is supreme in 1970's air superiority, but the thing is it stands alone here. You could've done exactly the same thing with Phantoms with complete parity toward any potential aggressors. And the cost factor of achieving this, largely academic exercise simply cannot be understated. Seriously, the entire nation of the US would've noticed, really noticed the difference if projects like the Valkyrie, Blackbird and Eagle were never started. And the defence industry wouldn't have been any the worse for wear in terms of maintaining parity with national security threats.
It is after all, a "defence" force, is it not? Which is why many other nations would declare the US is just as bad as the Soviets in the Cold War role, and is more like Hitlerian/Stalinist rearmament planners than anything approaching a benevolent democracy. I mean what else if not an imperialist agenda? And this is being played out right now in the Middle East and central Asia at least to a foreign perspective, these oil wars and industrial imperialism (we want all the money, everywhere, and bow down dammit, etc.).

 

[FLYBOYJ]

The Eagle had no advantages over the Foxbat from the Phantom (another conversation but my sources are Israeli combat records of Eagles versus Foxbats, mostly they all fired off all their missiles at each other without hits and then the Foxbats disengaged at a whim and were uncatchable, and Israelis have been known to chase enemy MiGs all the way to Egypt and get turned back by AAA over their home bases, if they could any way have caught a Foxbat in an Eagle, they would've).

The IDF Killed MiG-25s on the following dates

31Aug82
31Feb81
29July81

All F-15, All Syrian AF

 

[vanir]

And yet the only combat report where the Foxbats actually engaged Israeli Eagles, a two for two confrontation over the Sinai and the longest combat recorded between Eagles and Foxbats all missiles of both groups were used up with no hits and then the Foxbats finally disengaged and fled, leaving the pursuing Eagles behind.
All other engagements with Foxbats involved them firing their missiles defensively and fleeing immediately, which is why this one encounter stood out to the IAF. Following this the IDF took the approach of destroying them on the ground wherever possible, one particular strike on airbases had the specific objective of destroying landed Foxbats.

The incident where an Iraqi Foxbat downed a Hornet too was despite an escort of Eagles and Vipers, according to reports the Foxbats sped past the escorts to attack the strike aircraft without fear of interdiction.

But certainly Foxbats have been downed, the individual reports should be closely examined for context and circumstances however, outside ground based directors (designed support infrastructure), tossed into a furbee at low-medium altitude as an independent fighter facing an organised and tasked enemy using AWACS they don't stand much of a chance. If they get a lucky setup though, they do have the speed performance to be effective (but unreliable weapons).

I'm not trying to blow a horn for the Foxbat, simply pointing out that in the examples I had in mind where Foxbats did very well in combat, it wouldn't have made any difference if you were in a Phantom or an Eagle assuming a common weapons package. The advantages a 4th gen has over a 3rd gen didn't come into play on at least those two occasions (there is another inconclusive combat with Eagles but that was again defensive fire/flee on the part of the Foxbats, two missiles fired by the Eagles which went ballistic).