I just wanted to complete my series of posts regarding my assertions of the MiG 25 and F 15. Being the third time I feel I've been dismissively treated and countered at every turn when posting perfectly well reseached and as far as any credible sources attest, perfectly accurate information and personal appraisals, I'm not really interested in the forum any longer after only a short stay. I have other aviation forums where I dunno, the management and membership is just nicer, the atmosphere is far less competitive for every breath of even footing and just plain more intelligent, productive and accurate in a fair and reasoning manner.
In short, you're wack. In the academic sense.
As if I hadn't already displayed an extensive research of the Foxbats/Foxhounds...
To recorrect you FlyboyJ, deliveries of the Foxhound-A began in 1983. First Foxhound-B, MiG-31M pre-production development prototype was built in 1985 and was lost in 1991. 6 more were built from 1992.
Why are your responses consistently and offensively dismissive as opposed to simply posting clarifying facts from which your draw your impressions? Or perhaps you don't. And perhaps you just don't like environments of common learning.
Air doesn't enter Foxbat inlets supersonically to cause overspeeding. You can tell when entry air has gone supersonic, because on any engine other than a scramjet it causes immediate flamout, not overspeeding. You've obviously tried to apply Blackbird operational principles to MiGs.
Runaway engine rpm in the Foxbat was caused primarily lack of an air bypass in the single shaft Tumansky turbojets and a largely steel construction.
Due to the "bypass compression" facility of its J58 powerplants, Blackbirds had rather outboard engine mountings and this gave rise to the rather unique initial problem of engine inlets being outside the shockwave and splitter effect of a big cylindrical nose and thus readily subject to the entry of supersonic air at increasing mach speeds. Supersonically induced flameout was a problem which plagued the series. An ingenious system of retractable inlet cones was devised to control airspeed entering the compressor and in part serves to control engine performance at varying speeds and altitudes. Essentially, when one of the variable cone-geometry systems failed, Blackbird crews had an immediate flamout and unrecoverable loss of control was usually the result.
With inlets close to the airframe and set at a good angle, exposure to supersonic air entry is minimised, with the aircraft's nose acting to control shockwave position in relation to the inlets, however supersonic air entry is a constant concern in engineering high mach vehicles.
Throttle is an engineering term which describes the operation of any valve which controls fuel delivery to an engine (whether gaseous like air or liquid like aviation fuels). In effect the Blackbirds air inlet design acted as a secondary throttle control. The pilot's engine management control lever is used to control compressor and turbine rpm by means of an engine management system. Moving that could be termed as "manual throttle control."
Controlling the effects of engine overspeed at high mach with any kind of turbojet comes through controlling air bypass at the compressor. As operational temperatures increase, pressures between the compressor and the turbine try to get out of engineering specifications. The burny part gets so hot it starts to burn air without needing increased fuel flow to do so, and it no longer wants to stay where it was designed to be anymore, but tries to move to the front of the engine and use the compressor as another exhaust turbine. It's like shoving the throttle open much wider than it's supposed to go. You get turbine/compressor overspeeding. As you can imagine, extreme cases burn out the engines.
This is a rough description, but it'll do. Bypass turbojets such as the Aviadvigatel solve the problem by introducing cooling ducts just ahead of the turbines. The earlier Tumanskys sprayed water-methanol onto the compressor vanes.
Foxbat pilots with non-bypass Tumanskys experienced the tendancy towards "runaway rpm" at speeds exceeding 2.6 mach and according to my research were instructed to use very precise throttle control at those speeds. That is, they had to be very gradual and very gentle with the engine management control (throttle lever, engine rpm lever, turbine and compressor speed control lever or whatever you or a pilot feels like calling the manual throttle control), in order to keep turbine/combustion temperatures and pressures within specification. Mess about with a simplistic engine management at those speeds and you're just opening the door for temperatures and pressures to do something dramatic.
The reconnaissance-bomber and late interceptor BD series Tumanskys were never designed to go faster than 2.83 mach, they were merely designed to take a heavier load there. Primarily the Tumaskys had been designed to sustain 2.35 mach and dash to around 2.8 when needed. Later Aviadvigatels were designed to sustain 2.83 mach cruise.
The Blackbird dealt with bypass to reduce compressor overspeeding and took it to the next level, again with an ingenious inlet and engine casing design. It's variable geometry cone system also controlled a series of air bleed hatches in the outer casing and bypass doors directly to the afterburner; which were located ahead of the compressor. Combined with the J58's turbojet engine, it all gave rise to the technical specification of the J58 application as "high bypass air bleed turbojet engine" sometimes referred to as a "turbo-ramjet." Roughly speaking it functioned like an afterburning turbojet at low speeds, and a ramjet at higher ones, with air entry and compression controlled by the variable inlet cones, air bleed hatches and bypass doors to the afterburner, which virtually seals of its turbojet from the air stream. 80% of thrust is supplied by bypass air in J58 engines at 3.2 mach.
The two shaft Aviadvigatel engines of the Foxhound dealt with the issue by combining a turbojet bypass ratio of some .54 and a proportionately high functioning aspect and pressure ratios that was designed specifically to allow the overspeeding of normal turbojet operation by up to 140% with complete safety. This is adequate for a sustained cruising ability of 2.83 mach and simply translates "runaway rpm" into increased thrust or more controlled overspeeding. Put simply, the burny bit is contained where it's supposed to be, the compressor vanes are better heat tempered just in case, but it still tends to start burning air (best as I can figure based on my research). However, at speeds less than 3 mach turbofan engines are still more efficient than ramjet operation. As mentioned, these engines have sustained several hundred thousand flying hours of operational bench testing without incident (please research the nature of aircraft engine bench testing to give an idea of the particularly heavy stringency of this process).
The single and only reason cited by aviation reference sources as to the Foxhound-B not entering production was a lack of funding related to the economic collapse of the Soviet Union. No mention at any credible aviation site or reference source I can find suggests in any way this aircraft or the Foxhound-A is anything other than an excellently performing warplane. No experienced combat pilot with which I have spoken that has any familiarity with Foxbat/Foxhound warplanes has ever suggested they are anything but a genuine threat to front line US fighters and a perfectly capable, if highly specialised warplane.
The advertised g' ratings of air-superiority warplanes is quite subsonic in nature according to any research I've managed and is designed to reflect a combat aerobatic capability of those types. I in no way intended to suggest the MiG strategic interceptors could out manoeuvre air superiority fighters at dogfighting speeds and typical air combat altitudes. No supersonic g' rating is given for air superiority fighters, they do not dogfight at high mach nor attempt complicated aerobatics. The g' ratings given for MiG strategic interceptors is at high mach speeds, an appropriate comparison and the only one available would be the Blackbird series, which is most definitely not describable as a manoeuvrable warbird. It is the only other jet powered craft however geared to sustain high mach speeds over distances exceeding 500km, speeds which are roughly comparable and an aircraft which was investigated for strategic interception duties. The Foxbat/Foxhound series is more than 3 times its manoeuvrabilty at any high mach speeds.
It is unclear as to the manoeuvrability of composite/honeycomb warplanes at high mach and altitudes exceeding 40,000 feet (I've asked a pilot of these aircraft and am still waiting to hear back on this, but I've no intentions of returning to this forum). It is unlikely an Eagle will be pulling +9/-3 g's at Mach 2.5 and that height. My guestimate is half that would be lucky, composite skinning was postulated for the original MiG-25 but found inadequate for high mach operation, however these are not the conditions under which an F-15 is designed to combat aerobatically, this is the realm of BVR in standard US tactical doctrine.
My point was, at the extreme conditions for which these MiGs were designed they are quite manoeuvrable indeed, it is a lack of objectivity, deriving from an inaccurate generalisation which would claim they are totally hopeless warplanes. Theirs is outside the performance envelope the Eagle or any composite/honeycomb warplanes were designed to dominate, if you can maintain that envelope under air combat conditions they are themselves a more dominant warplane. With a roughly equivalent avionics/weapons technology it is a matter of tit for tat, not complete failure as you suggest.
Consider the intended application of strategic interception, specifically the Foxhound on the battlefield, with its phase array and "flight director" facility to shepherd dedicated counter-air fighters like the Flogger, Fulcrum or Flanker (a job taken up by the Su-30 variant in squadron service). It is not like the US air combat doctrine which stresses individuality and intiative over GCI and data linking. The Foxhounds hover up high over home territory, the Floggers/Fulcrums counter-air at combat altitudes with F-16s and F-15s. If the Eagles try to gain altitude and high mach for boom and zoom or BVR, the Foxhounds descend at much higher speeds, select individual targets and rely on solid construction and some 80,000lbs of thrust to evade and escape with a far greater rate of regaining altitude and a limited over the shoulder fire capability. The Eagles would be crazy to try following.
I've already considered the application by comparison, of US doctrine. Foxhounds come down from up high and Eagles select individual targets and engage at altitudes and speeds where their engineering specifications dominate the strategic interceptors, well outside their element. The Foxhounds would be crazy to come down and fight an Eagle.
It's not that one military is so much better than another, it's that either equipment reflect a different military doctrine, which in turn reflects different politics and domestic sociology.
This whole "the Foxhound is a pig" thing smacks firstly of ignorance, or otherwise mindless patriotism and little else. You have not flown a Foxbat and a Foxhound nor an F-15, your appraisal is not based on clear and well researched specific famliarity, at best you base your comments on limited hearsay and you are just not speaking authoritively.
You have displayed no significant knowledge whatsoever in any reasonable or detailed sense of these particular aircraft, especially in relation to their development backgrounds, detailed technological analysis and any objective appraisal of their capabilities, and I suspect your second rate aeronautics career has left you with a bit of a chip no subject-specific interested academic really wants to deal with. You're just not prepared to admit all it takes is research for person A to know more about something than person B, a failing I do not have. And I'm entirely too matured to bother with banging my head against anything so ridiculous and childish among other adults. Enjoy. I have no intentions of returning to these forums, being the second time desperately dismissive arguments have been put forth without so much as the slightest example of genuine research and based upon a sense of authority which simply does not exist. The problem is compounded by the formal support of site moderation to such ridiculous posts. I cannot think of any reason I should therefore find any interest here.
My own, final post to finish an earlier thought, for the benefit of browsers to the thread:
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Was the F-15 designed directly to counter the MiG-25 threat?
Two main points are:
First MiG-25 flight 1964.
FX programmed which resulted in the F-15 called for in 1965.
An additional point:
YF-12A and SR-71 programmes contracted 1962 after successful A12 trials. A12 and YF-12A programmes earmarked for cancellation by mid-1968, in 1966.
So far I've been able to come up with the original FX programme specifications of stressing high transonic and air combat (dogfighting) performance, twin engines with high thrust excess and an internal gun. High ferry range to deploy in Europe. Speed requirements to be in the Mach 2.5 class, Mach 3 was deemed too complicated and unrealistic for a front line fighter. It was specified the design must be able to overcome all potential current Soviet threats under typical air combat conditions. As at 1965. Gaining detailed information has proved difficult.
The YF-12 extension of the A-12 programme, in 1963 set its world straightline speed record of 2,070 mph (Mach 3.134) and altitude record of 80,258 feet. However it was already clear this aircraft was entirely too expensive and complicated to put into front line service as an interceptor. The YF-12 programme was therefore officially shut down by the Air Force by 1968 although it was taken up by NASA for technology development in 1969 (who maintained the prototypes until 1979).
Two specialised Ye-266 Foxbat variants set official world absolute speed and altitude records of an average Mach 2.806 over 1000km and 118,898 feet in 1967.
Development of the F-15 design began in 1967. I've no doubts the MiG-19 and MiG-21 being encountered at that time played more than a small role in its design considerations. I find it a little ignorant to think the MiG-25, so public at that time, didn't. However my assertion was, based on the claims of an ex-A12/SR-71 pilot's book which struck a logical chord, the F-15 was designed specifically to counter the MiG-25 outside of the realm of its performance envelope as part of a different air combat strategy to matching like for like.
First flight of the F-15 was in 1972.
In 1973 Israelis monitored an Egyptian MiG-25 Foxbat-B reputedly doing Mach 3.2 between two ground stations, whilst evading an F-4 interceptor, the news reaching US intelligence. The high speed was caused by its engines experiencing "runaway rpm" overspeeding and upon landing they had to be replaced. The canopy had blistered during the flight.
That year US Air Force Secretary Robert C. Seamans deemed the Mig-25 as, "Probably the best interceptor in production in the world today."
The same year the F-15 entered production.
In 1976 the SR71 (originally proposed by Kelly Johnson as a reconnaissance-bomber), broke the world absolute speed record doing Mach 3.204 over 1000km, snatching this back from the Russians in a rather public fashion.
The F-15 had entered combat service. US Air Force official release was that it had been designed to replace the F-4 Phantom II.
Before having posted all this I've waited to hear back from a combat pilot with over ten years experience flying various F-15 models, including 1 air-to-air kill (he now flies airliners). I figured he may have had some inside track from the briefing rooms and officers messes of operational Eagle squadron bases with the USAF. Here's what he had to say:
"Yes, the F-15 was built to counter the Mig-25. Intel blew its capabilities wayyy up and scared everyone.
The foxfire radar was supposed to be jam proof and the aircraft was supposed to be able to outmanuever anything we had.
The USAF/DOD had a blank check to develop the best air-to-air fighter possible to counter the threat. The F-15 was the result."
Link to the thread is here:
http://www.aviationforum.org/forums/showthread.php?s=&threadid=5429
At the very least this suggests some popular hearsay on the matter among experienced F-15 squadron pilots.
I'll leave it for individual browsers to draw their own conclusions and invite detailed research of what can only be described as perhaps the most fascinating era of warplane development, responsible for many of the air combat and strategic technologies in the world today.