|Last Updated: Fri Mar 29 10:48:39 UTC 2013|
Russia's Cold War Warriors
For much of the past two and one half decades the Foxbat family of interceptors have been the flagships of the Soviet Istrebitel'naya Aviatsia Protivo-Vozdushnoi Oborony Strany (IA PVOS). While the deployment of the newer Flanker has attracted much attention from Western observers, the Foxbat and Foxhound remain important types in Russia's air order of battle.
The Foxbat family of aircraft are by all means remarkable both technically and historically, and until the 1976 defection of Lt. Viktor Belenko, these large fighters commanded a respect which they hardly deserved in terms of real combat capability. The Foxbat is very much constrained in flight profile by its unique propulsion and is by all means a dedicated high altitude short range interceptor, its successor the Foxhound is a far more capable and flexible aircraft, but nevertheless still a dedicated air defence interceptor with no serious capability against existing teen series tactical fighters.
With the collapse of the USSR and the dissolution of Communism in Eastern Europe, arguably these aircraft are no longer major players. However, it is very likely that they will begin to appear in the Third World, in increasing numbers, as Third World governments take advantage of the financial crisis in the remnants of the Communist Empire. While both the Foxbat and the Foxhound are expensive to run and inflexible in role application, they are a high profile item and therefore likely to be attractive politically to Third World leaders with cash to squander. Therefore there is a strong case for examining these types in detail, if not for historical/technical interest alone.
The Foxbat was conceived during the height of the Cold War very much in response to the USAF's SR-71/A-11 and B-70 programs. The SR-71 and A-11 were the SAC and CIA versions of Lockheed's Mach-3 cruising strategic recce aircraft. The B-70 was to be SAC's supersonic cruising successor to the massive B-52, an aircraft designed to match the B-52's intercontinental range while cruising at speeds in excess of Mach 2.5 and altitudes of the order of 70,000 ft. The B-70 exploited compression lift, a phenomenon occurring at very high speeds, whereby large amounts of lift are generated by the trapping of the aircraft's supersonic shockwave under its wing and fuselage. With deployment schedules which called for the first operational wings by the mid sixties, these programs alarmed the Russians. Of particular concern was the SR-71/A-11, which had the potential to uncover much of the strategic deception via which the Communists maintained in the West an image of military and economic strength well beyond reality.
The IA PVO (Interceptor Aviation - National Air Defence Force) of the period relied heavily upon the MiG-21 Fishbed and the Su-11 Fishpot point defence interceptors, while ground based elements of the PVO depended very much upon the then new SA-2 Guideline Surface-Air Missile (SAM) system. Both the Fishbed and Fishpot were capable only of Mach 2 dash speeds and were armed with missiles capable only of engaging non-manoeuvring subsonic targets. The SA-2 had an effective ceiling of about 40,000 ft and rather inaccurate command link guidance. In the face of a Mach 3 platform penetrating at 70,000 ft, these weapons were as good as useless.
The Russians identified the SR-71 as the principal strategic air threat of the period and embarked upon a desperate crash development program to produce weapon systems capable of tackling the Blackbird. Not to do so would have allowed the West to unmask much of the illusion which the Communists had spent decades creating and could well have altered the course of modern history.
The Foxbat was to be the foremost of this generation of weapons.
The Mikoyan Ye-155/266
Confronted with the task of designing a fighter capable of climbing above 60,000 ft under 10 minutes, and capable of sustaining speeds approaching Mach 3, the Mikoyan bureau had to discard much of the established orthodoxy in Soviet fighter design. Initial studies on such a design commenced in the late fifties in response to intelligence reports on the Lockheed program, with official approval to proceed with the project granted in 1962.
The Mikoyan design team adopted a conventional layout, very similar to the NA A-5 Vigilante, but with two rather than a single vertical tail. This arrangement provided for unobstructed inlet tunnels to the engines, ramped variable geometry inlets and a capacious central fuselage cavity for fuel tanks, the latter an absolute necessity for a high energy expenditure mission.
Key problems encountered with design in this performance area are structural, finding materials capable of retaining strength at such high temperatures, and control related, ie the aft of the CoP with increasing Mach number resulting in turn in an ever increasing nose down pitching moment. The former problem was resolved by Lockheed in the US via the use of phenomenally expensive Titanium alloys, while North American used a mixture of steel and titanium. The latter problem was solved by Lockheed through the use of nose chines on the Blackbird, and North American via the use of canards.
The Mikoyan design bureau was constrained by the limits of Soviet metallurgical technology of the period and profligate use of Titanium was not an option, unlike during the eighties when whole submarines were built of it. Steel was selected as the principal structural material and welding as the technique to keep it all together. This capitalised on strengths in Soviet manufacturing capability. Steel was complemented by a D19 high temperature Aluminium alloy which comprised 11% of the emerging design, and Titanium was applied to critical areas, comprising 8% of the airframe weight. A side benefit of using welded steel is the inherent sealing of integral tank cavities.
Powerplant development proceeded in parallel, with the Tumansky and Mikulin bureaus focussing on low pressure ratio turbojets which would allow operation at high speeds without the internal temperatures exceeding the limits of the metallurgy of the day. An existing design, the R-15K, was used in a supersonic recce RPV designated the Yastreb (itself to later play a role in establishing the Foxbat myth), and this design was adapted for the project.
The first application of this family of engines to manned aircraft was in the Ye-150/152 series of the early sixties, these aircraft being conceptually similar to the MiG-21 but slightly larger and much more powerful. The 22,500 lbf R-15-300 was fitted to the Ye-150/152 airframes, soon followed by the 24,700 lbf R-15B-300 fitted to the Ye-152M/166 airframe. The engine soon proved its worth in the Ye-166 which was applied to breaking records, a favourite Communist pastime.
The R-15 is an unsophisticated single shaft design, with a five stage compressor with a pressure ratio (static/SL) of about 7, and a single stage uncooled turbine. The afterburner stage has three rings, and a variable area exhaust nozzle is employed. The engine burns a special T-6 high density fuel, with a freezing point of -62.2 deg C, a flash point of 54.4 deg C and a density of 0.83, which is slightly heavier than the USN JP-5 and USAF JP-6 high density fuels. At supersonic speeds water/methanol mixture is injected into the inlet to cool the compressor.
The R-15 is optimised for sustained supersonic flight, under which conditions it functions as a turboramjet, rather than turbojet. At high speeds, most of the intake air is compressed by the inlet, and therefore the low pressure ratio engine core adds little compression to it, essentially serving to feed the gargantuan afterburner with a flow of optimal temperature, density and oxygen content. Under these conditions most thrust is produced by the afterburner, and the SFC is as a result quite poor at 2.7. However, the engine can run under these conditions for as long as fuel and lubricant are available, unlike turbojets optimised for lower speeds which suffer excessive turbine inlet temperature rise resulting in hot end failures.
The penalty suffered by this powerplant configuration is abysmal subsonic and transonic SFC performance, resulting from the poor pressure ratio of the rudimentary compressor. An SFC of 1.25 in dry operation is 50% greater than it US contemporaries, such as the J79 at 1.9/0.84. An interesting comparison is the P&W J58 fitted to the SR-71A, which has an 8 stage compressor and 2 stage turbine, producing up to 34,000 lbf of thrust and exhibiting SFCs of 0.8 dry and 1.9 in reheat.
In hindsight it is clear that the principal limitations of the R-15 family stem from materials technology, which limited hot end temperatures and therefore forced the designers to adopt a low pressure ratio configuration. However, it was the best engine the Communists could produce and for its intended purpose of powering a point defence interceptor it was more than adequate.
Three prototypes of the MiG-25 were built, one designated the Ye-155P-1, an interceptor, and two as the Ye-155R-1 and R-3, the latter a theatre reconnaissance derivative of the basic design. All were powered by the 22,500 lbf R-15-300. Other than planned avionic fit, the principal difference in the airframes was in the use of additional integral tanks in the fins of the interceptor, which added 154 Gal to the 3,885 Gal of internal tankage. Filled with T-6 fuel, this yielded a max fuel weight of 32,350 lb and 33,640 lb respectively. For a TOW of the order of 80,000 lb, this yielded a respectable fuel fraction of about 40%.
The prototype aircraft were easily distinguished by smaller vertical tails and larger ventral aft stabilisers, in comparison with the production design. The recce model flew first, in March, 1964, soon followed by the interceptor in September that year. Intensive development testing followed, and concurrently, a number of speed and time to altitude records were cracked by these aircraft, designated for that purpose as the Ye-266 (a practice not unlike that of the RLM prior to WW II, creating fictitious designations for propaganda purposes). Fuel capacity was a major concern with the recce variant, with a jettisonable belly tank of almost 10,000 lb capacity adopted, while wingtip 264 Gal tanks were tested and rejected.
The aircraft's public debut occurred on the 9th July, 1967, at the Domodyedovo flypast, where two of the prototypes flew past the crowd and were extensively photographed. Foxbat hysteria ensued in Washington, as the type was erroneously identified as the MiG-23, which was known to be a low cost fighter in preparation for mass production.
The development process suffered from all the pains one would expect, the wing exhibited excessive dihedral effect in sideslip due sweepback, and this was initially dealt with by tip winglets, but subsequently fixed by a 5 degree anhedral. Aerolastic problems were experienced at high speeds due to the use of mid-span ailerons for roll control, it was believed that the application of aileron force away from the highly loaded wingtips would prevent this from happening, but the structural stiffness was still inadequate. The fix which was adopted was conventional, with roll control at high speeds provided by differential stabilator inputs.
The Ye-155P-1 (P=Perekhvatchik=interceptor) also experienced problems with asymmetrical missile launches at high speed, resulting in yawing and rolling moments due the sudden removal of the draggy underwing payload. This was rectified by adding in appropriate bias to the control system at launch to compensate the effect.
The MiG-25P interceptor entered series production in 1969, with an eventual IOC in 1972.
The MiG-25P Foxbat A
The production Foxbat A had a larger tail and smaller ventral fins than the prototype, while the nosecone was also larger to accommodate the large air intercept radar. A semiautomatic fire control system was fitted, coupled to a two way GCI datalink facility. While the prototype Ye-155P-1 initially carried only a pair of the massive AA-6 Acrid (R-40) AAMs, the production aircraft was equipped to carry four.
The core of the weapon system was a massive 1,100 lb I-band air intercept radar, the Smerch A, designated by NATO as the Foxfire. Designed for high peak power output to burn through jamming by a target's defensive ECM, the Foxfire was a pulse Doppler design with a limited look-down capability, and has been described as comparable in this respect to the AWG-10 carried by later USN F-4s. It is not unreasonable to assume that AWG-10 components retrieved from wreckage in North Vietnam would have been closely examined by the designers of the Foxfire. Western sources credit the Foxfire with a Search/track range of 55/40 NM.
The Communists built the Foxfire with the objective of engaging targets at all altitudes, including the standoff missiles of the period which were larger and flew higher than the later ALCM/GLCM. The Foxfire unlike its Western contemporaries, was built entirely with vacuum tubes, a technology which the Communist block developed to a fine art at a time when Western designers opted for semiconductors. While bulky, maintenance intensive and power hungry, vacuum tubes were relatively insensitive to ambient temperatures and EMP and thus were well matched to the environmental extremes of Siberian winters and central Asian summers.
The Foxfire was tightly integrated with a RSIU-5 VHF datalink, NATO designation Markham, reportedly a solid state design, this datalink carried radar video from a ground based GCI scope to the cockpit CRT display of the Foxbat, and also carried radar video from the Foxfire to the GCI station. During an intercept, the Foxbat pilot could approach his target silently on GCI video, and then light up his radar once in position to launch and guide his missiles. The GCI operator could simultaneously advise the pilot while observing a repeated image of the Foxfire's video.
The Foxfire/Markham system was complemented with, by Communist standards, a comprehensive nav/comm fit, including the RSBN-2 short range nav, the SP-50 Swift Rod ILS and MRP-56P beacon receivers, an R-831 UHF comm, a RSB-70/RPS HF comm with an antenna embedded in the leading edge of the left tail, and an ARK-5 DF set. The customary SRO-2 Odd Rods IFF was complemented by a SOD-57M Air Traffic Control/Selective Identification transponder. A Sirena 3 crystal video radar warning receiver was also fitted, it is considered comparable to the Vietnam era APR-25.
The sole weapon of the Foxbat A was the massive AA-6 missile, in its R-40R and R-40T CW SARH and IR Homing incarnations respectively. Comparable in size to the Raytheon Hawk SAM, the AA-6 was designed for maximum aerodynamic performance at high altitudes. Approximately 20 ft long, weighing in at about 1,500 lb with a 220 lb warhead, the SARH Acrid is credited with a range of about 25 NM, the IR version 15 NM. The SARH seeker will almost certainly employ a conically scanning mechanism due its age, while the heatseeking version will employ a rotating reticle seeker with most likely a PbS detector, typical for its generation. The SARH version relies on continuous wave illumination of the target by two wingtip mounted I/J band illuminators. In a typical engagement the IR round is salvoed shortly before the SARH round, to prevent fratricide.
The complexity of the Foxbat's integrated weapon system was considerable by Communist standards and its method of construction precluded the digital self test facilities then emerging in Western designs. Diagnostic tests were therefore carried out by plugging in an umbilical which fed a bank of diagnostic instruments installed in a 4WD van.
The Foxbat was redlined at 2.83 Mach and would experience airframe damage if higher speeds were sustained. This however was not known by the Americans, who were alarmed by the emergence of this type. They had mistakenly assumed the aircraft was built of Titanium, like the YF-12/SR-71 and the size of the engines implied a mass flow characteristic of an advance afterburning fan. The result was a Foxbat 25% lighter, with a combat radius in excess of 600 NM. The communists reinforced this mistaken perception by a clever and classical strategic deception, when they flew supersonic RPVs from a known Foxbat base in Poland over Western Europe. Assumed to be a Foxbat, the much longer ranging RPV was tracked on radar at radii which confirmed the wrong assumption, leading to eventual radius estimates of 1,000 NM at Mach 2.2.
The concern over the Foxbat escalated and had a major impact upon the design of the USAF's new FX (F-15), which grew from an F-18 sized aircraft to its present size to acquire the climb rate required to engage the supposedly long legged MiG. The reality of the Foxbat's radius was much less exciting, the massive SFC of the engines limiting the aircraft to a supersonic radius of about 300 NM and a subsonic radius of about 450 NM. Similarly its altitude and speed performance were inadequate to engage the SR-71, but this was not known at the time and hence the Foxbat fulfilled its principal function, ie keeping the SR-71s out of Soviet airspace.
Similarly the Foxbat's manoeuvre performance was mediocre, with a load factor at 50% fuel of about 5G, and much less at higher weights. The Foxbat was a single role interceptor with almost no capability to engage other fighters.
The myth of the Foxbat was shattered in 1976, when Lt. Viktor Belenko flew his aircraft from Sakharovka near Vladivostok to Hakodate in Japan. Distraught over the collapse of his marriage, the young PVO pilot feigned an engine failure and headed East, without suitable maps and with hardwired nav/comm equipment, to defect to the Americans. The Americans debriefed him for two weeks, continuously moving his location to prevent Communist agents from killing him.
Western analysts were given an unprecedented opportunity and the Foxbat soon sunk to its appropriate position in the threat equation. As a result, the Foxbat soon became a hot export item. Libya acquired 60 Foxbat As and 5 Foxbat B/Ds, while Syria acquired 30, supplemented by several recce versions, and Algeria acquired another 18, also supplemented by recce aircraft. India also bought the Foxbat, to the credit of the Indians they didn't bother with the A model and concentrated on the recce Foxbat B, acquiring a flight of eight for their recce 106 Sqn. Iraq later acquired 25 interceptors, but it is unclear how many where of the later E version, at least two were claimed by Sparrow firing F-15Cs of the USAF last year.
The MiG-25R/RD Foxbat B/D and MiG-25BM Foxbat F
The recce derivative of the Foxbat has proven to be a far more useful item than the interceptor. Production of this type also commenced in 1969, these aircraft being fitted with the more powerful R-15BD-300 engine. The principal avionic fit was a combination of optical cameras and a small SLAR (side looking airborne radar), the latter providing high resolution groundmapping of areas abeam the aircraft. Due the age of the Foxbat B, the SLAR most likely generated optical film strip outputs.
The MiG-25R was soon followed in production by a strike-recce derivative, the MiG-25RB, NATO designated the Foxbat D. The Foxbat D was to cruise at Mach 2.35 with external bombs, and deliver these under all weather conditions. All Foxbat Ds have provisions to carry two 1,000 lb bombs under the fuselage, and four such weapons under the wing pylons, with no defensive armament. Produced until 1982, the Foxbat D spawned a family of derivatives, the MiG-25RBK, RBS, RBV and RBT, which differed primarily in avionic and electronic combat systems. All Foxbat D derivatives are believed to carry a Doppler inertial nav attack system of unknown accuracy.
An offshoot of the Foxbat D was the Foxbat F, the FA VVS answer to the F-4G Wild Weasel. Using the airframe of the Foxbat D, the Foxbat F is fitted with a Radar Homing and Warning system (RHAW) in the nose and carries up to four AS-11 Kilter ARMs, a weapon not unlike the early Martel but somewhat larger. A ventral fuel tank of 12,000 lb capacity is carried under the rear fuselage. The AS-11 missile weighs in at 925 lb, with a 285 lb warhead, and ranges out to 26 NM.
The Foxbat B/D has been the most active subtype operationally, with many of these aircraft intruding into Iranian and Israeli airspace, prompting these nations to acquire the F-14 and F-15 respectively as counters. The Israelis are reported to have tried to engage Syrian Foxbats during the seventies with the F-4E/AIM-7E, and failed due to the AIM-7E proximity fuse being unable to trigger properly at the high closure rate. Subsequently, several Syrian Foxbats were killed by Israeli F-15As firing the newer AIM-7F missile.
The operational utility of the Foxbat D/F as a strike, recce or defence suppression aircraft must be questioned, as the aircraft's speed is of dubious value in airspace contested by teen series fighters firing missiles such as the AIM-7M or Amraam. Certainly the types track record is nothing to boast about.
The Foxbat D is important in having forced a requirement for better engine performance which led to the installation of 29,760 lbf R-15BF-2-300 engines, and later the afterburning derivatives of the Soloviev D-30, the D-30F (F=Forsazh=afterburning). Flight test platforms for this engine provided the basis for the Foxhound.
The MiG-25PD/PDS Foxbat E
By the late seventies it was clear that the Foxbat A had outlived it usefulness, and an improved version was sought. This was achieved by fitting the engines of the Foxbat D and a revised weapon system, built around the J-band RP-25 Safir-25 look-down radar, NATO code High Lark. The High Lark is used in the tactical Flogger, the most common strike fighter in the FA inventory, and later models have a facility to project radar video on the HUD, whether this model is used in the Foxbat is unclear. The High Lark is complemented by an InfraRed Search & Track Set (IRS&T), most likely the same equipment as carried by the Flogger B/G.
The MiG-25PD Foxbat E superceded the Foxbat A in production in 1978, with subsequent rebuilds of Foxbat A aircraft to Foxbat E standard receiving the designation MiG-25PDS.
The use of the Flogger's weapon system provides the Foxbat E with a capability comparable to or better than late model F-4E aircraft, and this is reinforced by the use of the same AAM fit as the Flogger. A typical load comprises a pair of SARH R-23 AA-7 Apex and two or four IRH R-20 AA-8 Aphid or AA-11 Archer, the latter a respectable dogfight missile. Later Aphids are all aspect capable, and can engage targets from 1,500 ft out to 3.7 NM. The Apex is considered comparable to the AIM-7 but is bigger and heavier at 705 lb, of which 88 lb is a warhead. The AA-7 comes in SARH and IRH versions, the SARH seeker is credited with a range of 20 NM against co-altitude targets and 12 NM against look-down targets, while the IRH seeker is limited to 8 NM.
The AA-11 is the latest IRH missile adopted by the FA, and is considered comparable to all aspect AIM-9.
The weapon system and weapon fit of the Foxbat E enables it to intercept low level targets and provides some measure of self defensive capability if engaged by other fighters. Other avionics were also improved, with ECM and expendables carried, and an ARK-15 DF set.
The aircraft is by current standards a useful air defence
interceptor with good supersonic dash performance, but its aerodynamic
limitations preclude its use outside of this role. Its weapon system is
inherently tied to a GCI environment and thus the Foxbat E is of
usefulness outside of its IADS.
The MiG-31B and MiG-31M Foxhound
The MiG-31 is the final and ultimate development of the Foxbat. The MiG-31 owes its origins to the upgrade program for the Foxbat D, which saw the D-30F fan installed in the Foxbat airframe. Derived from the D-30 used in the Tu-134 transport, the D-30F is a two shaft fan with a five stage LP compressor/fan with a pressure ratio of 3, and bypass ratio of 3, followed by a 10 stage HP compressor with a pressure ratio of 7.05. A can-annular combustor is used, followed by a HP turbine with two stages, and a LP turbine with another two stages. The afterburner uses four rings, and is fitted with a convergent/divergent nozzle with a substantial range of flow adjustment.
The D-30F has excellent SFC performance in dry setting at 0.72, and its afterburning SFC of 1.9 is also very good. These provide for excellent endurance in cruise and subject to fuel available, respectable endurance in afterburner.
Two Foxbats were fitted with the D-30F, and also fitted with larger fuel tanks, and these development aircraft achieved a range of 1,150 NM in supersonic cruise and 1,785 NM in subsonic dry cruise.
The first Foxhound prototype was initially designated the Ye-155MP (modified interceptor), but the scale of design change warranted a new name and the MiG-31 was adopted. The Foxhound was from the outset intended to be a long range look-down shoot-down interceptor, capable of engaging both low flying cruise missiles and penetrating bombers such as the B-1B, and to that effect was to carry a radar systems operator in a back seat position. The most visible differences between the types are the stretched forward fuselage, accommodating the new radar and additional crew station, and the extended tailpipes and reshaped vertical tails.
The internal changes are however quite substantial. Most of the structure is comprised of advanced Aluminium alloys, with titanium and steel used only in critical areas. The wing was stiffened with a third spar, the main undercarriage changed to tandem staggered arrangement to ease operation from soft or snow covered fields, the airbrakes were relocated, a LERX (leading edge root extension) was added to improve supersonic trim drag performance, a retractable refuelling probe was added and internal fuel capacity increased to 36,050 lb. A long spinal fairing contains a service duct and ends at the tail with a braking parachute container. The wing leading edges are divided into four flap sections, the trailing edges into outboard ailerons and inboard flaps. The wing pylons were changed and plumbed for 550 Gal drop tanks. Blow-in ports for cooling air are situated along the long inlet ducts, the inlets employ hinged lower lips and movable ramps to provide a optimal shock environment.
The area where the Foxhound is most exceptional is in its massive weapon system, built around the Zaslon, NATO code Flash Dance, phased array air intercept radar. The Flash Dance, developed in the seventies, was specifically designed to engage multiple low RCS targets in clutter, and uses an electronically steered phased array antenna, a first in a fighter aircraft. Using the same concept as the APQ-164 in the B-1B, the planar array is comprised of several hundred electronically controlled phase shifter elements. By selectively controlling the phase shifts of individual elements, the beam can be shaped and steered in fractions of a second, without any movement of the fixed antenna.
Technologically an equivalent to the Flash Dance could have been built in the West during the late sixties, but the weight and size penalties of this design technique outweighed its usefulness in fighter applications. Only the emergence of active phased arrays, using solid state transmitter/receiver/shifter elements, has led to the adoption of this technique for fighter design in the West, as the weight and reliability of the transmitter is vastly reduced by the removal of the heavy thermionic transmitter tube. Weight is however not an issue in the single role Foxhound, and the technology is therefore usable for the application.
The Flash Dance was designed with significant ECCM capability to counter jamming by the capable systems in the B-1B and B-52. The radar is described as substantially more capable than the F-14's AWG-9, in that it can engage multiple targets over a much wider azimuth and range of altitudes. Reports that the radar can see aft of the airframe are however not credible, unless a second antenna is fitted to the tail, as the fuselage aft of the antenna would severely interfere with the radiation pattern and produce unmanageable sidelobing. Regardless, the quality of the beam will begin to degrade significantly at larger angles off axis, producing a blind zone (torus) about the plane of the antenna.
The Flash Dance fire control system is coupled to a capable datalink allowing Foxhounds to exchange target data with each other and with ground stations, thus providing a good counter to jamming. Foxhound pilots claim the radar will reject chaff, and fire control algorithms in the software of the system can recover some target parameters denied by jamming using a range of techniques which were not elaborated upon.
The Flash Dance is complemented by an IRS&T set, in a retractable turret under the nose providing +/-60 degrees of horizontal and +6/-13 degrees of vertical field of view, to provide additional ECCM when confronted by heavy jamming. The fire control software can track a total of 10 targets in track-while-scan mode, select the four of highest priority and simultaneously engage these with AA-9 missiles, over an angular range of 70 degrees in azimuth and +70/-60 degrees in elevation. The system was observed during tests by a US recce satellite and can apparently kill cruise missile size targets at very low altitudes. Targets can be acquired at 110 NM and tracked at 65 NM, although no information is available on range against small targets at low level.
The Foxhound's weaponry is diverse and includes, strangely, a GSh-6-23 6 barrel 23 mm Gatling in a pod on the right hand side of the engine nacelle. While the gun has an impressive 8,000 rounds/min rate of fire, its utility on such a large and unmanoeuvrable aircraft must be questioned.
The primary armament is a quartet of large, active radar homing AA-9 Amos missiles, colloquially referred to by Soviet pilots as the 'Phoenix'. Similar is size and shape the the US AIM-54, the emergence of this missile only several years after the collapse of the Iranian government to the religious extremists, and the known sale of several F-14s to the USSR for testing purposes suggests the resemblance is more than coincidental. Until however an AA-9 is dismantled by Western analysts, we will not know exactly how much of its design originated in California. Carried in tandem pairs under the fuselage, like the Phoenix under the F-14, the AA-9 is credited with a range of 60 NM against closing targets. As an active homing missile, it will perform well in a jamming environment and against small targets.
The AA-9 is complemented by wing mounted AA-7, AA-8 and AA-11 missiles, providing a medium range and close in capability, although again the utility of the AA-8 and AA-11 must be questioned in view of the limited manoeuvre performance of the type.
The front cockpit is derived from that of the Foxbat, but includes additional displays for the weapon system, while the aft station has a large circular CRT not unlike that in the F-14.
Tactically the aircraft is often flown in sections of four, spread out to sweep a strip of 320 NM width, and using the datalink to coordinate operation. The philosophy of using autonomous fighters at extended radii is a radical departure form established PVO practice. The use of inflight refuelling allows for in excess of 6 hr of endurance on CAP. Deployed initially in 1983, by the time of writing over 200 were in service, deployed to sites about Murmansk, Archangelsk and Sakhalin, to cover key strategic targets.
With 33,750 lbf of afterburning thrust and 20,950 lbf of dry thrust per engine, the Foxhound is truly a supersonic interceptor, capable of sustained cruise at supersonic speeds. On a supersonic intercept cruising at 2.35 Mach it has a radius of 390 NM, on a subsonic cruise at 0.85 Mach with 2 tanks it has a radius of 755 NM increasing to 1,190 NM with inflight refuelling.
This is a capability with no equivalent in the West, the only aircraft in this class was the massive YF-12A which was cancelled in the late sixties due to its questionable usefulness in defending the continental US. However, the Foxhound is well matched to the uniquely Russian problem of covering vast areas with a limited number of aircraft.
The Foxhound is a good example of the Russian practice of wringing every bit of life out of an established design and will probably soldier on into the next century. In the changing world political environment it is however questionable whether the aircraft will be of use to its creators, given that its principal role, the hunting down of SAC's bombers and ALCMs, is now purely of historical interest. Expensive to maintain it is probably the least suitable type in the Russian inventory insofar as export goes, although unsuitability has seldom deterred the Third World from acquiring expensive toys.
Hopefully the Foxbats and Foxhounds will rust in peace.
First revealed in 1999, the MiG-31BM is a block upgrade to the
baseline Russian MiG-31B configuration. Initially Russian Air Force
planning envisaged the manufacture of new MiG-31M Foxhounds to replace
the legacy baseline variant, of which around 370 remained in service.
The MiG-31M was to carry the improved Tikhomirov NIIP Zaslon M air
intercept radar and
the R-37 / AA-13 Arrow Counter ISR missile, in addition to legacy
stores. Funding problems stalled this program.
A substitute effort launched in 1997 was a deep upgrade on the
MiG-31B configuration to the MiG-31BM, introducing most of the
technology developed for the MiG-31M but adding a robust multirole
The MiG-31BM is equipped with the Zaslon M phased array which
is claimed to
double the detection and engagement performance of the earlier radar
variant. Russian sources claim fighter sized targets can be engaged at
150 nautical miles, and detected at 170 nautical miles. Up to ten
targets may be engaged simultaneously. There are claims the Zaslon /
Arrow weapon system can be used to engage ballistic missiles in flight.
The MiG-31BM introduces a modern glass cockpit with AMLCD
panels similar to the MiG-29SMT, and an inertial / satellite navigation
package derived from the design in the MiG-29SMT variant.
The most prominent changes are in the weapon system. Russian
sources claim the MiG-31BM will be capable of carrying the the R-33 /
AA-9 Amos and new R-37 / AA-13
Arrow, the R-77 / AA-12 Adder or 'Amraam-ski'.
For strike roles the Kh-31A/P / AS-17 Krypton in
anti-radiation and anti-AWACS variants, Kh-25MP/MPU, Kh-29T and Kh-59 were
introduced, and up to three KAB-1500 or six KAB-500 smart bombs can be
carried, in television or laser guided variants.
The MiG-31F was a mid 1990s
proposal for a multirole variant, derived from the baseline MiG-31/31B
configurations, but equipped with a similar suite of air to surface
weapons as now seen in the MiG-31BM. The MiG-31FE configuration was an
export variant proposed for China, Saddam's Iraq, Libya and Algeria, or
other former Warpac client states. The strike capability enhancements
trialled in this demonstrator were later rolled in to the MiG-35BM
The mid 2007 announcement
that the "MiG-31E" would be exported to Syria, ex Russian Air Force
stock, with the R-37 Arrow, indicates that the export aircraft will be
based on the MiG-31BM and that the R-37 counter-ISR missile is in
MiG-31BM introduces a glass cockpit arrangement. Depicted WSO station and cockpit (Images via Testpilot.ru).
MiG-31F Foxhound demonstrator. The MiG-31BM exploits the weapon system designed for the MiG-31F, which was offered in MiG-31FE export configuration to the PLA-AF (Images via Testpilot.ru).
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