Fighter Performance: F-4 vs MiG-21

[michael82 0]

It seems that nobody agrees on these a/c abilities, agencies, air forces...not even Israelis

Has anyone else had a look on it at eBay and would offer a comment ?

Fighter Performance in Practice: F-4 Phantom vs MIG-21 - eBay (item 290477872650 end time Oct-20-10 05:49:04 PDT)

Thanks !!!

[+aleks 9]

the usual story:soviet jets and missiles were underestimated by NATO.perhaps, because of the practice to export "lighter"versions with inferior electronics to airforces without high leveled trained pilots....thank God the US forces used special training schools like the tp gun, to evolve practices nd manoeuver profiles for contrasting better armed and more agile rivals....i read once an article about mig 23, one of the more undervalued soviet aircraft.

[macelena 1,070]

Well, i´m not sure what you mean exactly or how much do you know about those aircraft, so i´ll just add the bit i know while someone else does better.

 

There were many different versions of both types, so it would make a serious difference. Many other factors would influence the classic dogfight scenario appearing in this kind of comparison. In example, altitude and speed. Low altitude and speed gave the Phantom an edge, and prefered maneuvers in the vertical. ( basically, using the energy of the aircraft to bounce up and down like a yo-yo), on the other side, the Fishbed was in its element at high speeds, thin air, and turning on the horizontal. The climb rate and max speed were even.

 

The Phantoms could carry other munitions for air to ground, however, those would be jettisoned before engaging in air combat. The Phantom had advantages like having a two men crew, better range, better weapons system with BVR capability (often limited by fog of war and IFF difficulties, but still there) etc. If i was to choose, i would pick the Phantom.

[JediMaster 451]

Of course, there's no such thing as an absolute stat of "F-4 performance" or "MiG-21 performance." The model, the funding and logistics behind it, the training for the pilot, the environment they're kept in, etc. Unless plane A soundly beat B every time (rarely happens) you can always argue one way or the other.

 

I mean, on paper the Me-262 bested the P-51 in almost everything, yet many a 262 were shot down by P-51s, so...

[ezlead 42]

You learn the machine. It's good points and bad. You fly its good points and avoid its bad. I would imagine if Steve Ritchie,Duke Cunningham and Robin Olds flew the Mig-21,they would have shot down a lot of F-4's.

The F-4 drivers will say the F-4 was better. The Mig drivers will say it was better.

There is no definitive way to say which was better. It all depended on the flight parameters during the fight.

It's like arguing Ford versus Chevy.

What I'm saying is:It was the man,not the machine!

Edited October 13, 2010 by ezlead

[+Gepard 11,356]

The question is which MiG-21 version vs which F-4 version.

For example: The MiG-21 pilots descriped the MiG-21F13 as a high agile plane "which would go into a curve when the pilot only was thinking about it". The MiG-21PF was descriped as sportsplane or MiG-21 GTI. The MiG-21M was descriped as agil as a lorry or moving van. The MiG-21MF was a bit better, but only at the first 500 meters it could match the climbrate of the MiG-21F13. And so on and so on and so on ...

With the Phantom its the same.

Edited October 14, 2010 by Gepard

[Nixou 25]

Also don't forget to take the price of an aircraft into account. If two countries with the same budget align their airforces, one having a worse but 4 times cheaper aircraft, the fight will be (oversimplified for the example) 10 vs 40.

 

Should the cheaper variant be worse in 1v1, it will probably still win because of numbers.

[Capitaine Vengeur 263]

Considering the high kills-to-losses ratio of the Israeli Mirage III over the Arab MiG-21, I used to think that although these dogfight planes were roughly comparable, the Mirage held an edge of superiority over the MiG. But I've heard that many of the Israeli pilots that have tested the MiG delivered by an Iraqi defector would have preferred to fly it in dogfight rather than their own Mirage, and were happy that the Arab pilots were so poorly trained in cooperating with each other. At least, the Israeli made a good use of the Mirage as a fighter-bomber, a role unfit for the short-winged MiG-21.

 

Such vain comparisons remind me of the tests the Americans made in 1945 on captured Japanese fighters of the latest generation. During these tests, they found these heavy energy planes to be roughly comparable to their own best planes, and even superior on some points. But these tests had been made using US pilots with more than 3000 hours of flight, not conscripted Japanese students, and using rich US fuel, not the infamous washed blend the Japs used by the end of the war, which stole 300 to 500 hp to their engines.

[vanir 0]

It is said in fighter weapons training the F-5 is extremely similar to the MiG-21 at low altitude and makes a perfect Aggressor squadron model for this reason. And they do very well not only against the F-4 in its day, but against the F-15. Given that the purpose of fighter weapons training is not comparative performance of aircraft, but advanced pilot training which can be deceptive about comparative performance in dissimilar combat training. Nevertheless the F-5 is highly respected as a low alt dogfighter and similarly, the MiG-21 at any height.

What is noteworthy about the MiG-21 is the workmanlike structure and rough finishing. It's cheaply produced and yet returns contemporary maximum performance. The Israelis noted with a little awe when the first F-13 was examined by western friendlies after defecting, that many of the panels didn't even fit flushly and it used ugly pop rivets in non-essential areas, but that these were on sections of the airframe in which it didn't adversely affect performance. Not to mention its rough field handling was superb for its time, it was low maintenance among contemporaries, it had short turnaround times and was easily and cheaply produced, with truly impressive figures including the world airspeed record.

 

So it was and remains, a mass produced legend. Straight up though, an Su-15 is a much more refined version of the same thing and a lot nicer to fly. But these were intended only for the PVO who got a special budget and an entirely different doctrinal approach. No expense was spared, but for Frontal Aviation everything was about overwhelming the enemy with numbers without breaking the bank so if possible, having semi skilled labourers making everything from refrigerator and toaster factories...no exaggeration (the main Fulcrum production line was initially in a refrigerator factory which continued to produce refrigerators for example).

 

So to me the comparison is a lot like the postwar evaluation at Wright-Patterson of the Fw-190D compared to the P-51D. The Dora was very roughly finished and in the words of the test pilot he was surprised it was airworthy, it was like a patchwork hotrod but despite scaring the pants off you it returned about the same performance as the Mustang, which was tremendously impressive. But on refinement, pilot confidence and overall airworthiness the Mustang won out, despite some experimental and highly advanced technologies buried in the Focke Wulf (like the aeromechanical screw, electrical everything and a rudimentary flight computer). That part is obviously different, the Soviets didn't really have anything on American contemporaries in avionics or equipment. In any case the conclusion was that for something which basically looked like it was thrown together in someone's backyard upon close inspection, its performance achievement as a late war contemporary was absolutely phenomenal, mind blowing as it were.

That I think, is the kind of light the MiG-21 should be held up to. For a very roughly finished and extremely simple machine, it has some terrific qualities and simply amazing performance...with an examination of its structure and finishing detail in mind. And it achieved its design goals perfectly plus at one time was the most numerous jet fighter on the planet.

 

It's like buying an F-5 that can beat F-4s on even ground at half the cost...and are generally speaking going to outnumber them 2 to 1 in any case. Something like an Eagle changes the game though, I think it's an unfair tendency we think of aircraft performance on those terms. No way a Phantom can match an Eagle either, you're talking 3g sustained turns as opposed to 9g with ease.

[Lexx_Luthor 57]

Wow thanks vanir great stuff. Soviet designers were fantastic, doing miracles with what they had to work with.

 

 

Su-7 original (pre -B) was front line fighter, and only a few squads made it before the type was made as fighter bomber. I've always wondered what the universe would be like if the MiG-21 was dropped and replaced by Su-7 then Su-17 optimized fighter versions much like MiG-21F was developed later. However, I've been told the AL-7 engine was very expensive at the time so I dunno. But, pilots loved flying the Su, maybe more so than any plane since Fokker D~7.

Edited October 25, 2010 by Lexx_Luthor

[vanir 0]

The Su-7 is an interesting breed, most people are very surprised to find out just how high performing the later Su-17 is in the Russian version with AL21 engines, a lot of exports had the MiG-27 Soyuz-Kachaturov engine fitted which is low altitude optimised and made it a mud mover only. I think most western impressions its performance are from these exports. But people like Egypt and Syria used some early Su-20 exports with the Lyulka engines and claim casual top speeds of anything between 2.04 and 2.2 Mach, they actually used them as ad hoc interceptors their altitude performance was so good and it probably had the best engine in their fleets.

 

According to the Sukhoi company the original Su-7 arose from a design team that was set up to copy the F-86 Sabrejet. They had some new ideas like all-moving tail and the variable nose intake, Arkhip Lyulka was using some very experimental technologies with his engine which produced a massive ~64kN dry (~88kN with afterburning) approved for service in 1954 (the contemporary J57 was rated for service at 44kN dry), and he was developing an advanced management control system probably a generation ahead of its time. It was a very complicated engine designed for supersonic flow into the first two compressor stages, with two sections for the afterburner and it impressed Stavka when the prototype cracked 2000km/h during initial testing. It entered a service evaluation phase after official testing from 1956-58 which involved 12 small production batches with various refinements so that 132 fighter airframes were manufactured and delivered between 1957-60 and they remained in front line service from 1959-65. What killed the project was really engine reliability within the parameters for the production of general fighters for Frontal Aviation. In 1958-59 the two directions taken for the engine were a revised afterburner section for carrying heavy stores as Frontal Aviation desperately needed ground attack sturmovik (Su-7BM and MK), and a more refined version was developed on the PVO budget for a redesign of the Su-9/11 series as the excellent Su-15 interceptor.

 

As it was the MiG-21 was already being refined during limited production batches by 1959 and this aircraft series perfectly fit the bill for Frontal Aviation of a cheap, mass produced and extreme performing model usable for a wide series of adapted roles.

My personal opinion is that if the USSR production philosophies and doctrines were more like the USA then probably the Su-15 would've been the main front line type in place of the MiG like the way the F-4 is really an expensive aircraft but wound up in huge numbers to push cheaper models like the F-104 and a mixed force composition into the background. The MiG-21 is a bit more like an F-104 with different fits for day fighter, forward deployment and all weather interceptor roles and was part of a philosophy which depended on a mixed force composition to satisfy the needs of Soviet combined air defence doctrine. I think the USA had it a bit easier in this regard, affording terrific expenditure on projects which never saw service but developed advanced technologies.

 

Also worth considering is that although the USSR may have numbers in the region of 2000 contemporary Frontal Aviation general fighters on station in the late 60s say, its sheer size means that only about 350 serviceable are available in forward deployment at any given defence district the size of a large nation, at a given time. And the philosophy was that in extended conflict PVO would provide support with their more refined models and modifications, and infrastructure. Hence the need for a "buffer zone" of satellites so that defence in depth maybe employed against NATO.

[Lexx_Luthor 57]

Awsim stuff thanks. Al-7 has always fascinated me. Su-15 for VVS may require assuming that VVS removes the option of operating from primitive airfields, although we did, so....or it could have used a larger and swept wing and more Tire rubber. Suppose Su-15 was derived from Su-7, but with a bit larger wing perhaps.

 

Worse, I've read the Su-15's radar and missiles required an enormous cockpit workload, throwing dozens of switches in sequence, and were geared strictly to high level ground controlled intercept far more so than F-4 which at least had AIM-9s. I think the F-4 worked in this regard so early in tactical BVR mainly because it had two seats, unlike the -15.

 

Thanks!!

[+Gepard 11,356]

The Su-15 was a pure intercepter with no single kilogramm for air to ground action. It had not had a gun, only missiles. Later a gunpod was adopted. It was to difficult to operate under the conditions of semi prepared airstripes. In that point the MiG-21 was superior. It was able to take of from grass or sand stripes which were located only some kilometers behind the frontline.

[vanir 0]

Oh I totally agree. I only meant if the VVS was more like the USAF this might've been the road taken. This is kind of an example that superior avionics development for the most part resting with the USAF was largely by choices involving doctrinal approach rather than any inherent incapability on the part of the Russians.

The MiG-21 and Su-7BM were almost perfect choices for Frontal Aviation.

 

Certainly the Su-15 existed in a rudimentary era for radar/fire-control systems, the <10% success ratio of missiles in Vietnam can attest to their poor reliability even for the USAF. Solid state electronics were only just beginning to be developed and radar sets used valves, had virtually no data handling capacity and required dedicated operator workloads. The radar set in US single seat interceptors (F-102/106) had its own joystick and required the pilot to bury his face in a HDD shroud and that was pretty advanced, during this interception phase the aircraft was piloted remotely by a ground station (you wouldn't want enemy EW aircraft/ships in the vicinity). All the fighters back then, especially considering poor ECCM, newly discovered phenomenae involving signal interpretation, unreliable IFF within ECM environments, installing a radar for regular counter-air work was virtually token anyway, it was almost only usable against high flying large bombers. The Israelis virtually never used theirs (in Mirages and F4s) relying instead on SA outside the cockpit and CWC (guns, heatseekers), in fact the IAF prided gun kills above all other kinds right up until receiving Eagles and even then didn't consider the AIM-7F very reliable.

 

As it turned out one of the best features of the F4 in its era was having a second crew member not for operating the radar but for improved SA in close fighting, since typically all aircraft of the period had poor pilot cockpit view. The Su15 is an exception to this rule with quite good pilot view from its bubble type canopy. It had blown flaps introduced during production so its handling during take off/landing cycle was exceptional for the time, and it was perfectly capable of operating from the smaller, low maintenance fields typifying forward deployment models. This was necessary because of its poor range, but an F4 doesn't do much better without external tankage and aerial refuelling in this regard either.

Also the Su15 was later developed for a limited ground attack role at the request of the PVO (TM model produced alongside T 1970-76). One prototype was used to test a capability for operating on unpaved airstrips, another for in-flight refuelling and two others modified as buddy-tankers. Its role as an interceptor was one largely of fit, it was a fairly ubiquitous design. It was certainly more complex and expensive than a MiG-21 or an Su-7. It was less purpose built than a MiG-25 or a Tu-28.

 

I don't see any reason you couldn't operate an Su15 from the same fields as a MiG-21 and you could certainly operate it from shorter ones or higher altitude ones. Some of its northern district fields around Murmansk, or eastern ones were pretty rough. The major difference would be ground support, the MiG has lower maintenance and higher turnaround (plus being much cheaper/easier to produce), which is better for a forward deployment model. But going back to the USAF comparisons that simply makes the Flagon more like an F4 than an F5, the MiG is like an F5 that flies like an F104 and that's the thing which makes it so impressive. Hence my remark that if the VVS was more like the USAF probably the Su15 would've been the main front line type in the role of the F4, while the MiG-21was a completely different kind of thing much more like the role of the F5.

[Lexx_Luthor 57]

Okay then, how about a Yak-28P derivative instead? It had two seats, although it had its own issues I suppose.

 

Be careful with the bubble canopy. Soviet aircraft had a knack for burying pilots in a bathtub. MiG-15 was described that way -- bathtub -- and so had poor visibility downwards, contrasting with the F-86's high perch mount for the pilot. Anyways, I see Su-15 as absolutely the sharpest looking "everyday" tire kicking plane ever made, although it could have been made to look even better. And it was. The Camel cigarette corporation did just that in the 1980s. I'll explain.

 

I was in a 7-11 or something convenience store, about 1989 or so. There was a cardboard Camel cigarette display, and along with Joe Camel wearing shades, was the coolest plane I ever saw. It was, literally, an Su-15TM double delta, but with some clever Modding: First, it had circular/cone Mirage-3 style inlets, and as the French know, such inlets get the girls more often than rectangular inlets, and it may have had twin vertical stabilizers, but I don't recall that now. Most significantly for young American male smokers who couldn't fly Tomcats in the NAVY because they "messed up their knees in Hi~School football"©, the Ca-15TM, we can call it after the Camel design bureau, was taking off from a carrier, the twin engine double "swoosh" curving back down to the deck below. Smoothest plane I ever saw. I never smoked Camels though so even that didn't sell to me.

 

Thanks again!!

[+Gepard 11,356]

I don't see any reason you couldn't operate an Su15 from the same fields as a MiG-21

 

Its a question of the landing gear and the weight of a plane. The landing gear of the Su-15 was not really fitted for grass stripes. On the one hand the plane was to heavy for it and on the other hand the tail section of the Su-15 was to low over ground, so that it was always a risk to touch the ground while landing.

The same problems had had the MiG-23. Only the MiG-23ML seria was able to operate from grass stripes. For the MiG-21MF it was forbitten (following the LSK (east german Air Force) doctrin).

 

The MiG-21 in contrary had a max take of weight below 10 tons and had relativly big low pressure tires. Take off and landing operations from grass stripes were regulary trained.

 

And to Lexx idea with the Yak-28. I have read somewere an interview with a soviet fighter ace of the Korea War. If i remember right it way Mikhin or so, will try to find it. The guy said, that after his return to the USSR his unit was reequipped with Yak-25 and later Yak-28 and he disliked both planes. In contrary to the MiG-15 or 17 it were no planes of the pilots wishlist.

 

EDIT:

 

And here the link to Mikhins interview:

http://www.airforce.ru/history/cold_war/mihin/mihin_en.htm

Edited October 29, 2010 by Gepard

[Lexx_Luthor 57]

Thanks GR. Gotta love the short answers. But, this...

 

Next meeting did not take place – on 25.03.2007 Mikhail Ivanovich Mikhin passed away...

 

 

Yefim writes about MiG pilots thinking of Yak-25 as too heavy, but, that may be natural as other pilots from different backgrounds seemed to enjoy it, or so he wrote.

 

And, Mikhin is another who preferred -15bis over -17, although its possible he means dry -17. I recall another interviewed pilot (?) said MiG-17 too heavy, but -17F would have been nice to have.

[+Gepard 11,356]

For me it was also interessting to hear, that some east german pilots who migrated from the MiG-15bis to the MiG-17 had the same experience as Mikhin. It seems to be, that not only Mikhin was not a big fan of the MiG-17.

[vanir 0]

Its a question of the landing gear and the weight of a plane. The landing gear of the Su-15 was not really fitted for grass stripes. On the one hand the plane was to heavy for it and on the other hand the tail section of the Su-15 was to low over ground, so that it was always a risk to touch the ground while landing.

The same problems had had the MiG-23. Only the MiG-23ML seria was able to operate from grass stripes. For the MiG-21MF it was forbitten (following the LSK (east german Air Force) doctrin).

 

The MiG-21 in contrary had a max take of weight below 10 tons and had relativly big low pressure tires. Take off and landing operations from grass stripes were regulary trained.

 

And to Lexx idea with the Yak-28. I have read somewere an interview with a soviet fighter ace of the Korea War. If i remember right it way Mikhin or so, will try to find it. The guy said, that after his return to the USSR his unit was reequipped with Yak-25 and later Yak-28 and he disliked both planes. In contrary to the MiG-15 or 17 it were no planes of the pilots wishlist.

 

EDIT:

 

And here the link to Mikhins interview:

http://www.airforce....in/mihin_en.htm

 

Thank you, I enjoyed reading the interview.

 

I think you are right about the Su15, it certainly wouldn't make the better forward deployment/fast turnaround fighter than the MiG, the same way of why the USAF uses both F-15 and F-16 so they have a different model that can be used from forward strips for frequent missions. I did specify for its era it is more like an F4 than the MiG, which is more like an F5. But I was not thinking at all about operating from unpaved/grass strips which obviously the MiG can do which is a good point and a further bonus. The Soviet air forces would have to have been very much like the USAF to have operated the Su15 as the main front line type like the F4, restricted to the same kind of fields that the USAF uses (large paved ones with complex ground support services and close supply). I think they only would have done this if they were just a foreign version of American air forces instead of a completely different doctrine, and for these differences the MiG-21 and Su7BM were perfect choices.

 

Those early BVR radar sets were very big and heavy, around half a ton sitting in the nose. That alone generally means an airframe design that isn't going to have the best inherent field manners in a second gen supersonic. The MiG-23ML serie had two benefits over its predecessors being the much lightened radar/fire-control and I think it first received AoA sensor for inlet bypass doors, both things improving low speed handling and I guess making operation from grass strips more reliable (better approach speeds, more effective flare and go-around capability), although I thought Czech MF serie operated from grass.

 

Similar to you guys the only good reports I've read of the MiG-17 is with the F engine in the Middle East but by then it was up against the Mirage III which was of course quite superior (better than twice its initial climb rate for a start). The Yak-25 and 28 certainly don't look like models which would get a "seat of the pants" fighter pilot very excited. The -25 has a massive early radar and two low-power engines, from what I've read it seems to be an early attempt to deal with the long range northern defence district, protecting the arctic approach from bombers. I guess it's really along the Tu-28 line of development, it has a very good range for its time but nothing like the performance of small light fighters, much heavier and underpowered. The -28 is much faster with afterburning but 50% heavier again and initially developed for the multirole direction with an interceptor variant. By this time however the Tu-28 was in development for the northern district region and long range intercept role and had much better range and equipment for the long patrols needed. When the Tu-28 started entering service the Yak-25 was completely phased out at the same time, but it is remarkable some Yak-28 remained in service until the 1980s. Reportedly it had quite good low altitude characteristics.

 

It's important to note I think the very different roles for a PVO pilot to be assigned to the arctic patrol than it is point defence of the Moscow district. Totally different aircraft design requirements are necessary. I don't think you can fairly compare a MiG-15/17 with a Yak-25/28 or a MiG-25 with a Tu-28 for that matter. The PVO requests that multi-crew aircraft are used for these long range patrols because they believe there is a psychological element to patrolling the vast arctic wastes which is much better served by multi-crew interceptors, they believe morale is a problem for single seat solitary patrols and the pilots go a bit crazy after a while. True story, there is a bit of superstition about long range arctic patrols, the Inuit and Siberians have entire mythologies based on the psychological effects of "being alone among the ice expanse" for extended periods, believing such people become ghostlike demons that haunt the wastelands. I suppose on a pragmatic level these airfields are already relatively isolated, cut off for parts of the year and then their pilots going out for 3-4hr solitary patrols on rotating shifts and drinking vodka on down time aren't the best pastimes for their mental health.

 

There is a lot to consider in design requirements for the Northern or Eastern District arctic patrollers and point interceptors. They must operate in a low maintenance environment, carry a lot of survival equipment, must be all-weather and suited to cold operations, and the patrol-interceptors should be multi-engine and multi-crew for reliably sustained operations with long flight endurance. Nominal range should exceed 3000km although this wasn't a requirement for the point interceptors protecting major ports like Murmansk. Supersonic capability is of course preferred, point interceptors need good transonic acceleration but mostly the patrol-interceptors just need good range with a good dash capability when given a target direction.

But the point defence interceptors of PVO are meant for a dual role of defending major installations from nearby stations and a support role in counter-air during major conflicts where they will assist Frontal Aviation as necessary (the priorities in this case go defending high value Army sites near the conflict independently, then supporting Frontal Aviation, then finally defending Army troop concentrations). So the point interceptors of PVO need mostly climb rate and transonic acceleration capabilities, and good offensive armament and characteristics against both enemy bombers and tactical aircraft like escort fighters or strike models, a nominal range of only 1500km is typical.

 

Say for example you're going to compare a MiG-17 with a Yak-25, the MiG has a great climb, excellent counter-air performance, a high ceiling. It doesn't have anything like the all-weather capabilities of the Yak and would run dry halfway through one of its patrols, which are rated as more effective and sustainable in the two-crew configuration. The strategic threat at this time for the Yak to counter was the slow Convair B-36 whilst the MiG would be tasked probably against the B-47 Stratojet along western approaches across continental Europe and the Mediterranean, or against Vladivostok from Alaska. It was a much more dangerous type for its high speed (very difficult to intercept) but its short range meant it had to face the Soviet defence in depth strategy to attack targets, only the Convair could get across the arctic with a significant nuclear payload in the early 50s and Yaks could handle them. In a sense the Yak is really built more like a long range escort fighter than a traditional interceptor, which the MiG is much more like.

[+Gepard 11,356]

To come back to the Phantom, i want to tell you a little bit, what i have heared from west german F-4F pilots. They told, that in mock dogfights the F-4F had a fair chance against the mighty F-15A in the 70th and early 80th. The west german dogfight tactic against the Eagle was to dive down and to try to lure the Eagle in a low altitute engagement. At low altitudes the first F-15s in Europe were limited to 6.5g only, while the F-4F was able to pull 7.5g, what meant, that the F-4F was able to hold its own at low altitudes against the Eagle and with a little bit luck it was able to score.

Completly different was the outcome when dogfighting at middle or high altitudes. Here the Phantom was unable to beat the Eagle.

[vanir 0]

That is very interesting. What I've read and heard from USAF/MC pilots substitutes speed performance in that rendition for g-tolerances. In fact according to some Vietnam vets in the same kind of transonic manoeuvres where a Hornet can sustain 7g a Phantom can only manage 3g. Meanwhile the low altitude g-tolerances of the Eagle are infamous and it's widely celebrated as pretty much the strongest fighter airframe there is in this realm, the conclusion of dissimilar flight training against the West German MiGs through the 90s was that the Eagle should always dive to low altitude with them in close combat because it can far exceed the Fulcrum's airframe tolerances, where at medium and high altitude the Fulcrum is capable of bringing its nose around quicker. There is no way a Phantom would match a Fulcrum or a Viper down on the deck I should think, but an Eagle can and easily.

 

By contrast the Phantom has terrific speed performance at low altitude, a lot of the American fighters of that period do, for example the century fighters can all manage a good 1.2 Mach or so on the deck which few modern fighters can do, actually only models like the F-111, F-15 or a MiG-31 can do those sort of speeds in thick air (aircraft like the Mirage series are all subsonic at sea level). But the Phantom drops off on supersonic performance as altitudes rise compared to lighter or more modern types, specially prepared record attempts aside. Models like the MiG-21 have superior altitude performance and modern fighters like the Eagle far exceed those.

 

Are you sure those West German pilots were talking about high stress manoeuvres rather than low altitude speed related characteristics?

 

The Phantom has some real low altitude interceptor benefits, a lot of the dedicated strike aircraft like the Jaguar or MiG-27 and Su-24 have poor altitude performance but fantastic low altitude speed performance exceeding 1.12 Mach dash for strike missions, being optimised for this realm. Point interceptors like the Mirage can't catch them, but a Phantom can.

 

Plus I've never heard of a stress limitation less than 9g for an Eagle that wasn't directly related to the tracking ability of its sidewinder models. Some of them can't track targets during high g manoeuvres, the Vietnam era Sidewinder was restricted to 3g or it would go ballistic (MiG-17s soon found they could just stick to circle tactics against Phantoms in close combat to prevent Sidewinder locks and bring guns on anyone foolish enough to try attacking them without extending, more than one Phantom was shot down this way).

 

Also a MiG will only manage 7g on a good day and whilst the Phantom could far outdo one in the vertical, it was no match in a turn fight at any speed short of the transonic realm and even then only because the MiG lacked boosted controls. I'm kinda doubting sustained 7g capabilities of a Phantom on the deck, I think it's more like about 4-5g which is pretty reflective of its structure and era. Foxbats are constructed almost identically and have that rating, and as I mentioned US Vietnam vets say the limit was 3g in a complex CWC manoeuvre if you expected to keep the fight going.

 

I don't really know myself, do we have any sources to work with?

[Caesar 305]

I know I don't always agree with his conclusions, but I'd like to hear what Streak Eagle has to say about the Phantom's envelope - from what I understand, he's researched the hell out of it. For that matter, on the deck, you're going to have more "g" available with denser air moving over your control surfaces at any given speed. Your "g" authority, both sustained and instantaneous gets lower, or requires higher speed to reach, at higher altitudes. It follows that if an F-4 can perform a 7g+ turn at, say, 450KIAS at 20,000 feet, it can most definitely yank that same "g" at low altitude. As can a MiG-29 match an F-15C's 9g turn at low or high altitude.

 

Also, how are your aircraft loaded? "g" limits change for any number of reasons, not the least of which is loadout and weight. If your jet is flying with external tanks, or high internal fuel quantities, its placard limit is not going to be the same as the actual limit at that weight.

 

To make it easier, say we have aircraft X. Aircraft X's placard limit is 7.3g - say this is at a weight of 45,000 pounds. If aircraft X is loaded to 50,000 pounds, its "g" limit is 6.5g. At 55,000 pounds, its "g" limit is 5g. As weight burns off (either as fuel, or weaponry) the limit increases back to the structural placard limit at 7g. Every airframe, for the purposes of making it last for a long time, has this same "changing" g-limit due to weight/loadout. Also, if tanks are loaded, the limit can drop enormously. I recall reading an unclassified report from an exchange pilot on the MiG-29, indicating it only has a 4g limit while the centerline tank is installed and still carrying fuel. Good luck fighting an F-15A, C, E, or otherwise anywhere with a 4g limit, and an alpha limit as well in that configuration!

 

(EDIT): That limit is also a symmetric "g" limit. Rolling limits are slightly or sometimes significantly lower than the symmetric limit, because the aircraft has differential "g" being loaded on the airframe during rolling and pulling maneuvers.

 

Of course, in air combat, I can't think of any pilot who would follow "g" limits religiously if his/her own life, or that of the crew, were in peril. If you need to put on a 10g or 12g+ instantaneous turn to get out of the way of that missile, or to exchange energy for turn performance to kill that enemy who has been trying to kill you, you do it. Better to bring back an airframe with less available hours of flight remaining than to sacrifice the life of the aircrew because of some line on a chart, and I think every pilot I've spoken to who has been fired at has told me just that.

 

We must also remember that "g" and "g" limits aren't everything. I've been fortunate enough to talk to a good number of F-14 drivers and RIO's who were, or rode with, excellent sticks that mastered slow speed BFM/ACM. Constantly loaded up on alpha, and rarely getting up to or higher than 3g once the fight slowed down, they'd mercilessly beat smaller, more nimble aircraft that didn't handle as well at such slow speeds, due to their higher wing loading, or where their pilots were uncomfortable flying right at the edge of stalling. One of those pilots I had the pleasure of speaking with would do the same thing in the F-4D as a AF Reservist against F-15 drivers (A or C), and come out on top at high or low altitude.

 

But more than the plane, alpha or "g" limits is the pilot. The better pilot, who knows his/her own plane AND the enemy's, who understands the advantages and disadvantages of each airframe, is going to have the advantage in a dogfight. This was said earlier in the thread, I've said it before myself, and I will never be of an opinion otherwise. Pure fighter performance? I'd give it to the MiG-21 across the majority of low to mid-speeds in a turning fight, with the F-4 just catching up at higher subsonic speeds, but never really exceeding the MiG-21's turn performance. In the vertical, the F-4 seems to me the better candidate.

Edited October 31, 2010 by Caesar

[+Gepard 11,356]

It seems to be, that the g-limit of the F-15A was limited for the first time of their duty in Europe. Personally i think that it was only because of safty restrictions. Also today new introduced planes have a limited flight envelope in the first time. At Berlin ILA airshow i saw some years ago Mirage2000 or F-16 flying smaller circles than Eurofighter or Saab Gripen. Not because the later planes are unable to curve better, but because the pilots were still restricted not to overcome certain limits.

Same will be the reason for the F-4F "victories" over the Eagle.

[vanir 0]

Yeah this makes sense

(EDIT): That limit is also a symmetric "g" limit. Rolling limits are slightly or sometimes significantly lower than the symmetric limit, because the aircraft has differential "g" being loaded on the airframe during rolling and pulling maneuvers

 

I don't really know much about it myself. I only go by what I can figure out as a layman and what vets and the like say.

I did go back over some documentary footage I've got featuring some Vietnam vet Phantom pilots and two statements stood out. Firstly that under certain conditions a Phantom was capable of pulling 6.5g but also that statement I reiterated earlier, with a slight correction that in the same kind of turn that a Hornet can do 7.5g the Phantom can manage to do 2 to 2.5g (I incorrectly remembered it as 3g), the pilot here was trying to place in context the handling of the Phantom compared to modern fighters like the Hornet, Eagle and the like.

Essentially he's saying it's a whole different kettle of fish and doesn't handle anything like a modern composite/honeycomb supersonic turbofan.

 

Another vet (Robin Olds I think) said you don't get in a fight with a MiG-21 at altitude in a Phantom, you're going to lose. He was describing an encounter where he decided to bug out from a high altitude fight with two Fishbeds, and tackle them another time under more favourable circumstances. Yet in an F-15 you can easily, very easily out turn and out power any MiG-21 at any altitude, there's a nice description of some IAF Eagles tackling 5 or 6 Fishbeds and absolutely dominating them in close combat manoeuvres every which way from sunday. One simply must infer that no way a Phantom could keep up either.

 

Certainly I appreciate that new models will have conservative restrictions. Thus I don't challenge Gepard's relation in any way, but I can't help becoming very curious about the specific context involved and details. It's interesting.

 

 

 

[vanir 0]

I recall reading an unclassified report from an exchange pilot on the MiG-29, indicating it only has a 4g limit while the centerline tank is installed and still carrying fuel. Good luck fighting an F-15A, C, E, or otherwise anywhere with a 4g limit, and an alpha limit as well in that configuration!

 

I remember reading something similar, from the commander of JG73 iirc who said the Fulcrum was g-restricted with the centreline tank only if it had fuel in it, unrestricted if it was empty. It was the weight distribution but otherwise it was a conformal tank. It was also modified so that it didn't interfere with gun case ejection like other 9-12 centreline tanks (the 9-13 corrected this). The context he was discussing this was to say that the Viper (and Eagle or Hornet) was g-restricted even if it was carrying empty external tanks and had to jettison them for 9g manoeuvring. The Fulcrum could keep an empty centreline (conformal) tank if it was empty and use its maximum limit (but it was still speed restricted). So it was actually a bonus that a Fulcrum could keep its centreline tank after it was empty and it didn't interfere with manoeuvre performance, so you didn't have to keep replacing tanks back at base because they really needed to carry some external tankage due to very thirsty engines (they have a pretty insane afterburner setup, ergo the derating kit replacing the hot section with something stronger). I think you're right about the Alpha limit however with the centreline tank, but the Fulcrum safety system has an alpha limit within its specification anyway, you have to switch it off to do 30-degrees (which you can do safely flying clean because of its inherent stability). In any case the digital-FBW control system of the Viper has a more restrictive alpha limit than the Fulcrum in any configuration, you can't switch it off and just have to fight the stick.

 

But there were a few other points to add. The Luftwaffe found the Fulcrums cracked around the base of the fins from sustaining 9g manoeuvres with Vipers and this was an unrealistic limit (despite MAPO claims of an 11g absolute limit). According to the Germans the max Fulcrum limit is 8g under 0.8 Mach and 7g above that speed, where the Viper limit is 9g at any speed and Eagles have seen 12g before. The conclusion of dissimilar flight training with the German MiGs was that at low altitude the Fulcrum simply cannot stick with the best American models in high stress turns (Block 30 and 50/52 Viper or Eagle), and Vipers were much quicker on the deck without afterburners. At medium and high altitude however, only a Block 50/52 Viper is capable of bringing its nose around as quickly. The advisory was in close combat for Eagle pilots to draw Fulcrums to the deck and crush them with sheer airframe strength and avoid turn fights at altitude, or otherwise stick to BVR. A Block 50/52 Viper is considered worthy of dealing with a Fulcrum at any height but needs to look out for those Archers. The Germans also rated the Fulcrum as unsuitable for any NATO combat operations and only really good for dissimilar flight training, but it does have its strengths.

 

To make it easier, say we have aircraft X. Aircraft X's placard limit is 7.3g - say this is at a weight of 45,000 pounds. If aircraft X is loaded to 50,000 pounds, its "g" limit is 6.5g. At 55,000 pounds, its "g" limit is 5g. As weight burns off (either as fuel, or weaponry) the limit increases back to the structural placard limit at 7g. Every airframe, for the purposes of making it last for a long time, has this same "changing" g-limit due to weight/loadout.

 

This is very relevant to the Flanker. Nominal advisory is 7g with 9g allowed from what I've read. But that's without the long range internal tanks filled, when it has about the same internal fuel load as an Eagle (about 6 tons) with similar performance capability. With the "special long range tanks" filled which aren't normally for regular counter-air missions it carries over 9 tons of fuel and is restricted to about 5g. But Eagles almost always have external tankage so are restricted to 4-5g unless jettisoned, whilst Flankers with a full AA loadout (about 2 tons) I believe enjoys the nominal 7g rating if the long range tanks are left empty. The guage redline in the cockpit starts from 8g and goes to 9g iirc but this would undoubtedly be the relatively clean and light configuration (nominally 4-6 Archers and long range tanks empty).

 

I don't think the Fulcrum guage has a redline marking but MAPO claims it has a 9g nominal rating with 11g absolute, nobody else agrees with them though and the Luftwaffe has evidence it's an exaggeration.

 

 

Like you say though it isn't really indicative of actual manoeuvre performance, from what I've gathered there is a turn chart used to determine best corner speed and turn rates of various fighter types which is far more associative. On one of these charts aircraft like Phantoms are well below the turn capabilities by airspeed of modern fighters like Fulcrums and Eagles. An F-15 really can sustain 8g turns in the region of 0.75 Mach with phenomenal rates it takes something like a Fulcrum or a Flanker to beat which they do with a tighter circle and slightly less corner speed/loading, something like a Phantom is going be doing a couple of hundred miles an hour slower to even try to match the circle and won't get anywhere near the rates, whilst trying on an instantaneous 7g is just going to dump all your energy to keep the fight going if you miss the shot, if you can even get a shot.