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MiG-31 Firefox
A model of the fictional MiG-31 "Firefox" from the film starring Clint Eastwood, based on the novel by Craig Thomas.
About this creation
Technical Specifications:

Designation: MiG-31
NATO Codename: Firefox
Nation of Origin: USSR
Manufacturer: Mikoyan-Gurevich
Type: Advanced Interceptor
Power-plant: 2 Tumansky RJ-15BD-600 Turbine-Based Combined Cycle (TBCC) engine (low-bypass/high-bypass) afterburning turbojets/ramjets each producing in excess of 22,700 kg (50,000+ lbs.) of thrust at reheat; 6 Soyuz/Komarov hybrid rocket boosters producing an additional 7,218.6 kg (15,900 lbs.) of thrust combined or 6 High-Test Peroxide (HTP) “Thermal” Ignition System Kerosene-burning rockets producing 4,000 lbs. of thrust each (24,000 lbs. combined)
Span: 13.34 m (43 ft 9 in)
Length: 19.25 m (63 ft 2 in)
Height: 4.97 m (16 ft 4 in)
Empty Weight: 24,569.12 kg (54,117 lb)
Loaded Weight: (wing hardpoints free) 37,103.15 kg (81,725 lb)
Max Speed: 5,741.98 kmph (3,568 mph) (Mach 5+)
Max Ceiling: 36,728.40 m (120,500 ft)
Range: approximately 4,828 km (3,000 miles)
Crew: 1
Armament: 4 modified R-98 MT (AA-3-A) Advanced Anab air-to-air IR/thought-guided missiles housed in two internal weapons bays; twin cannon with 250 rounds of 23x115mm ammunition per gun; two additional hardpoints on each wing for unspecified ordinance
Defense: 4 rearward pods (on each wing and vertical stabilizer) armed with
anti-missile flare dispensers; 2 rearward pods (at rear of fuselage) armed with
anti-missile chaff dispensers; 100 23 mm flare and chaff rounds supplied to cannon
via a dual feed system; electronic countermeasures (ECM) to jam enemy radar
Airframe: angular titanium/stainless steel/nickel alloy; "Cranked Arrow" wing platform
Special Features: Radar Absorbent Material (RAM); thought controlled weapons management system; fly-by-wire control system; Terrain Following Radar (TFR); variable-geometry wing tips; variable-cycle engines; fuel-cooled airframe; cryogenic heat exchanger system for maintaining a low fuel temperature and for the pre-cooling of engine intake air
Year of Manufacture: 1982
Production: two prototypes; one destroyed in a mid-air explosion.
The fate of the remaining airframe remains unknown.

The MiG-31 was designed to be the fastest interceptor in the world and be itself uninterceptable. Its super-stealth technology would allow it to be able to get within visual range of its prey with little threat to itself. The “Firefox” could therefore attack with impunity in a fashion like the German night fighters of WWII; an invisible harbinger of destruction on the Soviet Union’s capitalist enemies. By getting in close, there would be the element of surprise with little chance to evade the MiG’s short-range missiles and cannon.

An auto-destruct mechanism is activated when the airframe becomes submerged in water. A small red placecard measuring no more than 5 mm long appears at eye-level in a perspex window in the lower forward section of the fuselage below the cockpit. Below the window it reads "In the event of red placecard, cordon off airframe and advise Senior Armaments Officer", indicating small explosive charges have been armed. On drying out, a small cylindrical detonation device trips two solenoids, setting off charges designed to destroy the top secret electronics on board, so preventing them falling into enemy hands.

The weapons system is thought activated and controlled utilizing an EEG feedback system. Electrodes in the fight helmet detect brain impulses and, through the weapons control computer, allow the selection and firing of weapons without the time delay involved in manually flicking switches and depressing a firing button. This gives the pilot a decisive advantage over an opponent. The only disadvantage is that you must think in Russian. Specially adapted missiles can also be thought-guided to their targets using the onboard radar to track their progress. The USAF experimented with such a system in the 1980s, but the complexities encountered resulted in the concept being abandoned. In the novels, it was Dr. Pyotr Vassilyevich Baranovich who was the creator of the thought controlled guidance system, though he had originally intended it to be used more benignly; for wheelchair operation by the totally disabled. After eighteen months of development on the prototype, the project was acquired by the Ministry of Defence for the "Firefox" project.

In the US, the “Advanced Tactical Fighter“ (ATF) programme resulted from 1970s studies on the changing face of air warfare in Eastern Europe and the Middle East. By the 1980s, the programme’s emphasis had focused on producing a warplane with short take-off and landing (STOL) and supercruise abilities (achieved through the new advances in alloys). It would possess supermaneuverability, utilize composite materials and advanced avionics and fly-by-wire flight control systems. Higher power propulsion systems would produce greater speeds and low-observable technologies reduce its radar signature. The result was the YF-22 and YF-23. Anticipating this threat, the Soviet Union initiated its own fifth-generation jet fighter programme. Officially, Mikoyan proceeded with two concurrent projects, a heavy multi-role design "Multifunctional Frontline Fighter" (MFI), and a light tactical fighter named "Light Frontline Fighter" (LFI ). Two aerodynamic test airframes were designated 1.44 (NATO nomenclature “Flatpack"). The 1.42 incorporated further improvements (NATO nomenclature "Foxglove"). In 1983 the Soviet government amalgamated the two projects into the “Combined Task Programme” (CTP) with the aim of reducing the escalating development costs involved in developing two entirely separate aircraft. It is speculated that these two fighters were actually preceded by a third, earlier, even more ambitious project: that of the MiG-31 Firefox Advanced Interceptor, intended to bring down the likes of the SR-71, cruise missiles and bombers and eliminate AEW&C aircraft without detection. The CTP arose from the need to undertake drastic cost-saving following the loss of the Firefox prototypes and the unsustainable drain in resources that would be required to continue the MiG-31 project.

Some similarities between the MiG-1.42 and the MiG-31 aircraft are striking. The MiG-1.42 had all-moving canard wings affixed to the forward fuselage to aid in low-level/low-speed characteristics for a statically unstable design. The delta wing had a wing leading edge sweep of 40–45° and the vertical fins were widely spaced. The undercarriage comprised a conventional tricycle arrangement. Stealth was a significant part of the exterior design of the 1.42. Mikoyan’s engineers undertook extensive wind tunnel testing to hone the 1.42’s aerodynamics and reduce the radar cross-section (RCS). Stealth was enhanced through stowing weapons in internal bays. Range was reportedly 2,500 miles, essential for long-range patrol and interception. Without thrust vectoring, however, the Mig-31 lacked the MiG 1.42’s high manoeuvrability and STOL capabilities, it instead focusing on hypersonic speeds and new advanced electronic stealth technologies.

The MiG-31 Firefox's development would have likely benefited enormously from the SUKHOI T-4 Mach 3 (3,200 km/h) reconnaissance/anti-ship/strategic bomber project. Canceled in December 1975, it had made a multitude of engineering advances including the extensive use of titanium and stainless steel as well as the incorporation of a fly-by-wire control system.

The Firefox cockpit features a centre stick and left hand throttle controls. The pilot sits in a KM-1M ejection seat. The cockpit has both conventional dials and CRT screens. No HUD display is seen in the cockpit; instead, a Shchel helmet mounted projection system is used.

The pilot who steals the "Firefox", Mitchell Gant. The figure separates to allow the torso to be seated in the cockpit. The flight pressure-suit holds a Personal Survival Beacon. On immersion, it transmits a frequency-agile SOS signal. This multi-band transmission is more likely to be picked up by search parties, improving the chances of rescue.

Two cannon barrels are housed beneath the fuselage in the fuel cooling system air- intake. This position ensures that the oxygen-starved gun exhaust gases are not drawn into the engines, thus avoiding the risk of a flame-out. Like in the early MiG-25s, they may belong to a Gryozev-Shipunov 23 mm Gast Gsh-23L cannon, the streamlined "belly-pack" GP-9 gun pod being housed within the ventral cowling. If equipped with the SPPU-22 pod’s traversable ability, the cannon could be angled up to −30° from their normal 0° position, allowing it to strafe large targets such as bombers and E-3 AWACS. It is a highly reliable weapon with a rate of fire of 3,000 or 3,600 rounds per minute with a muzzle velocity of 700 m/s, but the GP-9 pod would have to be modified to have chute-fed ammunition which could return spent shells to the magazine as the standard case-ejection ports would spill spent shells into the huge engines. According to "Firefox Down", however, standard NATO ammunition was substituted for the usual Soviet rounds in a large drum. As 23 mm ammunition is not a NATO standard calibre, this leaves 30 mm ammunition as the only one common to both forces. The guns could instead be a pair of 30 mm Gryazev-Shipunov GSh-30-1 cannon (also known by the GRAU index designation 9A-4071K) which entered service at the same time as the manufacture of the MiG-31 prototypes. It is the lightest Soviet gun of 30 mm calibre and has a rate of fire of 1,800 rounds per minute (normally limited to 1,500 rounds per minute to reduce barrel wear). A large drum would indeed be necessary to carry a sufficient number of these bulkier rounds for a sustained dogfight. Its maximum effective range against aerial targets is 1,200 to 1,800 m (3,900 to 5,900 ft). It is reported to be extremely accurate and powerful, capable of destroying a target with as few as three to five rounds.

Despite the excellence of the GSh-30-1 and its timely introduction, it is an unlikely choice for the “Firefox”. Firstly, it has never been seen mounted in pairs on any Soviet/Russian fighter. The combined weight of two GSh-30-1 cannon is 92 kg vs. the 50 kg of the twin-barrelled GSh-23L, creating an additional burden when excess weight needs to be kept to a minimum. The big sister of the GSh-23L is the GSh-30-2. There is little possibility that this ground-attack weapon would be used on a high-performance fighter though, being nearly half a meter longer and 64.5 kg heavier. Secondly, despite the commonality in calibre, NATO rounds are of different lengths compared to Soviet rounds and so are unlike to fit. A more probable scenario is the use of 23 mm ammunition claimed from a downed Soviet-built fighter. Thirdly, the “Foxhound” carries a fixed six-barrelled GSh-6-23 cannon fed by a 260 round magazine. Thus, it would seem logical that the “Firefox” could possess a similar larger magazine of 23 mm shells. More ammunition would need to be carried by the "Firefox" due to the emphasis the Soviet Air Defense Force placed on the interceptor's foreseen tactical advantage in close-range combat engagements. 23 mm ammunition, in addition to the usual high-explosive incendiary (OF2) and high-explosive incendiary tracer (OF2T) rounds, also comes in chaff (PRL, with base expelled chaff particles) and flare (IK) varieties (as used by the tail turrets of Russian bombers like the TU-22M3) so allowing the guns to lay a form of missile countermeasures ahead of the aircraft. A burst of 50 flare rounds with the traversable barrels set to −30° (fired in an arc to distract away from the aircraft and prevent impact with its own shells) would create an IR signature akin to that of a fighter more rapidly than many dedicated flare launchers. By including a similar number of chaff rounds to produce a radar return, a more realistic decoy can be produced. A limited number of these special rounds could be kept in reserve and fed through a dual feed system allowing them to be employed when the need arose. They certainly would be a useful addition to the “Firefox” armoury!

By placing the missile armament in internal bays, the radar signature of the aircraft is significantly reduced. Combined with the MiG's other super-stealth technology, this allows the warplane to be undetectable by radar systems. The substantial reduction in drag also reduces fuel consumption and enables hypersonic speeds to be achieved without the weaponry being literally ripped off the wings.

Boeing's X-32A Joint Strike Fighter concept demonstrator was also designed with side-mounted weapons bays for both operational and supportability reasons: it gave ground crews eye-level access for maintenance and weapons loading. This feature benefited the US Navy armourers that were tasked with re-equipping the “Firefox” on the ice flow. The MiG-31, however, differs from the X-32A in mounting its missiles on the doors themselves. This unfortunately has the draw-back of temporarily exposing the weaponry to enemy radar and so detection. The doors would, therefore, be opened at the last possible moment and closed after firing.

The "Firefox", had it entered production, may have been followed by a reconnaissance variant similar to the MiG-25R "Foxbat B". By replacing the missiles in the weapons bays with pallets containing Side-Looking Airborne Radar (SLAR) and/or Synthetic Aperture Radar (SAR) and cameras (side-looking and vertical), an unrivalled and uninterceptable surveillance platform would have been produced.

As in the MiG-25, the flat linear surfaces of the engine cowlings and the thin cross-section of the wings offer lower air resistance at high speeds.

Small extendable boarding steps are carried internally below the cockpit and are used to aid the embarking and alighting of the aircraft.

The Ye-155-R1, the original MiG-25 prototype, like the Ye-152P, had the provision for the installation of moveable canards to improve pitch control. The "Firefox" also has control canards, their limited angle of movement can be inferred from the flattened oval area along the forward fuselage flanks. High aspect ratio foreplanes improve handling at low speeds and when undertaking high angles of attack e.g. when landing and taking off. The canards also give lift to counteract the weight of the advanced avionics in the nose section. Ailerons on a delta wing increase lift, but pitch the nose downward. The canards also counteract this and reduce the landing speed. Like the moustache canards of the Tu-144, they swing back when supersonic speeds are obtained in order to avoid wave drag. By adding a small inward movement as the canards retract into the aeroplane, gaps that would otherwise form between them and the forward fuselage are avoided. The canards are unable to pivot in this retracted position and must be extended again if manoeuvrability is required.

Note also the air-to-air refuelling receptacle behind the cockpit for use with flying-boom type tanker aircraft. It is likely to be a boom operating Tu-16Z tanker prototype or the prototype Il-38MZ tanker from the air-to-air refuelling trials of the 1960s and '70s that was refurbished and put back into operational service for use on the "Firefox" programme. The USSR normally employs the simple probe-and-drogue means of refueling rather than the more complex flying-boom, but the large fuel capacity of the MiG-31, and the fast changing environment in which it was envisaged it would operate, made the high flow rates of the more elaborate system necessary. The sole tanker prototype fitted with a flying boom was used to refuel the second "Firefox" prototype when it was sent to intercept and destroy the MiG-31 stolen by Mitchell Gant.

In Craig Thomas' novel, the Firefox carried four Advanced Anab missiles. The film version of the interceptor, however, required the missiles to be carried internally as
the air resistance produced would prohibit hyper-sonic flight. Anabs are too sizable to be housed inside even a large fighter. The problem was solved by miniaturising them to a size small enough to be carried by a man unaided.

Pictured are (from left to right) the 'Mini Anab' missile, an Aphid Missile (the smallest air-to-air missile the Soviets had in 1982) and an Advanced Anab. (Please see "Russian Missiles in Lego" for the latest improved versions of the latter two missiles). I placed four hardpoints on the wings as the large wing area begs for armament and the larger missiles provide a greater interception range. Internal 'Mini Anabs' would be the only armament carried when hyper-sonic flight was required.

Missile Specifications:

NATO Code Name: Ahid B AA-8
Soviet Designation: R-60M
Length: 2.09 m (6' 10.2 ")
Diameter: 0.12 m (4.72")
Range: 4 km (2.5 miles)

NATO Code Name: Advanced Anab AA-3-A (AA-6 Acrid)
Soviet Designation: R-98MT
Length: 4 m (13 ' 1")
Diameter: 0.28 m (11")
Range: 23 km (14.4 miles)

Note: the Aphid B also had a laser proximity fuse and could be fitted with a warhead laced with 1.6 kg (3.51 lbs) of depleted uranium to increase the impact of its small fragmentation warhead. The 'Mini Anab', being even smaller than an Aphid, would also require such a warhead to be effective.

(Please see "Final Alterations..." page for images of widened wing with leading edge flaps.)

Like the “Foxhound”, the “Firefox” had the ability to engage multiple targets and a look-down, shoot-down capability. It is likely an experimental scaled-down version of the N007 Zaslon electronically scanned phased array radar was fitted with its multi-target tracking ability. The antenna is fixed, the radar beam being moved electronically. This allows faster beam steering and the operating range is extended by using the full fuselage diameter to act as the antenna. The terrain following radar (TFR) is of an advanced, fully digital type. It is difficult to jam and avoids detection through intermittently switching off when not generating a terrain profile. The TFR is also capable of generating throttle commands so reducing the pilot's workload when flying at low level.

Two air brakes are housed in the upper fuselage spine allowing rapid deceleration.

A panel opens to reveal two fuelling points. Like the “Foxhound”, there may have been plans to plumb the outboard pylons to accommodate two 2,500 liter underwing fuel tanks in order to extend its range even further. Thermally stable Soviet T-6 fuel is used, mixed with an oxidizing agent for more efficient combustion, together with a caesium containing compound (equivalent to the SR-71's A-50), which helps disguise the radar signature of the exhaust plume.

The friction produced at high Mach speeds as a result of air flowing over the airframe requires that the fuel be cooled. The large air scoop under the fuselage channels a flow of air through the heat sink of a cryogenic fuel-cooled heat-exchanger system designed to keep the fuel at a safe temperature. This warmed air is then fed to the engines to be added to the by-passed air while the fuel, after gaining heat and vapourising in the heat exchanger system, is burnt by the combustor. This therefore makes a water and methanol injection engine cooling system, as used in the MiG-25, unnecessary. Special very low volatility JP-7 fuel (which necessitates the use of a Triethylborane ignition system), as utilised by the SR-71, is therefore not required. In order to combat kinetic heating of the airframe itself, onboard fuel is circulated beneath the surfaces experiencing the greatest heat fluxes.

Cooling the jet fuel down to -3.8° C increases its energy density, enabling an aircraft to fly further on the equivalent volume of fuel. Refrigeration also has the added benefit of preventing fuel vapour from building up in the plane's tanks which reduces the threat of an explosion should the vapour be exposed to a spark. Injecting nitrogen gas into the fuel tanks while the chilled fuel is being loaded replaces oxygen in the tanks, further eliminating the possibility of accidental combustion. The nitrogen is ultimately vented out of the tanks to be replaced by air.

It is speculated that the support struts/vanes at the mouth of the air intakes may hold a series of tubes through which coolant from the heat-exchanger flows. These would pre-cool the air passing between them before entering the first-stage compressor. Pre-cooled jet engines have much higher thrust and efficiency at speeds up to the “Firefox”’s maximum of Mach 5.5. In 1955, Robert P. Carmichael determined that pre-cooled jet engines, for a given overall pressure ratio, have a significantly reduced compressor delivery temperature (T3), delaying the point when the T3 limit is reached as the aircraft accelerates. Corrected flow conditions (as those encountered at sea-level) can therefore be maintained after the precooler over a very wide range of flight speeds, maximizing net thrust. Pre-cooling the intake air subjects the compressor and ducting to much lower and more uniform temperatures, allowing greater utilisation of light alloys, thus greatly reducing the weight of the engine, further adding to the thrust/weight ratio.

The landing gear can be deployed in flight to act as a further airbrake. It is likely the synthetic rubber tyres are impregnated with aluminium powder in order to reflect back some of the heat generated by the airframe through kinetic heating.

Every effort was been made to maximise the fuel capacity to feed the massive thirsty engines. As in the Su-35, fuel tanks have even been included in the bases of the vertical tailplanes. The fuel load is sufficient to achieve a phenomenal ferry range of nearly 3,000 miles at sub-Mach velocities (~600 knots) at high altitude. This maximum figure is significantly curtailed if super-sonic velocities are reached, though super-cruise is possible at Mach 1.5 so conserving some fuel. Energy consumption increases exponentially at increasing hyper-sonic speeds, but the six rocket motors which aid initial acceleration use different fuels. Note the rear-facing drone launchers on the tailfins.

There is an abrupt transition between the sculpted faceting of the nose, ventral air intake and engine nacelles and the smoothly curved mid-fuselage and spine. Such contradictions are seen in Sukhoi’s PAK-FA prototype. The angular fuselage and cowlings disperse incoming radar waves and so reduce the overall signature of the aircraft. The special black paint also has an absorptive/deflective property. The latter seems to be an active system, coupled with the interceptor's advanced ECM electronics. This was proven to be the case when, in "Firefox Down", the fighter became submerged in a frozen lake and, after recovery, then failed to be immune from radar detection.

The single weakness dispayed by the MiG-31 is the massive heat signature produced by the two Tumansky RJ-15BD-600 high-bypass afterburning turbojets. The only defenses the warplane has against Infra-Red homing missiles are the four detachable drone units and, of course, its great speed which can allow the interceptor to literally outrun them.

The fuselage tail fairing, like in the Su-35, houses an aft-facing radar (possibly the SPO-15M, serving to give early warning of a rear attack and forms part of the thought-controlled weapons system) and, uniquely, a rear-view camera, a useful combat feature. To make room for this equipment, the brake parachute that is normally fitted to fighters like the MiG-25, has been dispensed with, the engines instead providing a degree of reverse thrust for additional braking with cold by-passed air from the engines being diverted forward, passing through the ventral duct. This nearly proved disastrous for Mitchell Gant's daring ice floe landing; unable to use the disc brakes for fear that his high speed would shear off the landing gear, he relied on the snow covering the ice and a combination of his engines' reverse thrust and air brakes to slow him down. He managed to stop the aircraft just a few meters short of the edge of the ice flow. Clearly, the addition of a parachute would have given him a much greater margin of safety.

The "Drone Tail Unit" in the novel became four separate rearward flare dispensers; one on each wing and one on each tail fin. A similar housing is seen near each corner of the engine cowlings. Are these for ECM? The wing drone-pods serve the secondary function of helping to optimise air flow and maintain the area ruling for best supersonic performance.

The exact nature of the "Done Tail Unit(s)" remains uncertain. The novels state there are four "rear-defense pods" which detach from the aircraft and ignite. In the film, however, the pods seem to remain intact and, indeed, the same one (intentionally or unintentionally) appears to fire twice. The tear-drop shaped pods possess four holes and when seen from the rear, superficially resemble wing-mounted rocket launchers. The projectile nature of the flares is indicated by Mitchell Gant's command "Fire rearward missile" and they do indeed leave the aircraft at considerable speed. In the film, Dr.Baranovich informs Gant that the rearward defense pod fired explosives aft. I conjecture that the pods are intended to be launchers for flare rockets (possibly a truncated form of the 55 mm diameter S-5-O type flare rockets which did have the option of being mounted in quadruple launchers when first introduced), their motors ensuring that distance is rapidly put between the decoy and the aircraft with a small warhead detonating at the end of the burn. They appear to emerge lit, with the fold-out fins deploying to allow the flare to turn into the wind. Like Orbital ATK’s HAPS system, the flare rocket could act as a kill vehicle, guided by a fast-sync wireless command guidance link, using its fins to perform pitch manoeuvres in order to intercept the threat.

The propellant would be a Mg/Teflon mix or similar, producing an I.R. signature akin to that of the flare itself. The rocket propulsion would aid the rapid deceleration of the decoy when travelling at very high speeds rather than accelerate it away from the aircraft as its forward momentum must first be countered; this is the fundamental drawback of an aft-firing weapons system on a fighter jet. If each pod dispenses four flare rockets, the total number of drones increases four-fold to sixteen.

The novels state the flares burn for four seconds with a combined temperature exceeding that of both of Tumanski engines combined, short of full power. I speculate that, as the flares do not leave a smoke trail, they could be of the pyrotechnic MTV variety, electrically ignited, with a double-base propellant. Alternatively, alkylaluminium pyrophoric flares produce bright emissions similar to that of jet fuel and form large flames, so this type could also have been used. As for the similarly shaped pods in the corner of the engine cowlings, they could possibly hold a modified form of the S-5P/1 chaff rocket. The debate continues...

Three rockets beneath each engine nozzle aid rapid acceleration to hyper-sonic speeds (Mach 5+) or can assist take-off when under full-load. The rocket boosters use solid propellant with a special smokeless formulation and a rod-and-tube grain configuration to produce near constant thrust. They are hybrid rocket motors which can be ignited, throttled up and shut off at will. They can also be employed as an emergency measure at extreme altitude where the thin air can cause 'flame-outs' of the main engines. The rockets would likely be a development of the Kartukov Bureau's SPRD-99 RATO bottles as used on the MiG-21 and the Yak-28, but with much longer burn duration. The slower burn rate does, however, significantly lower the thrust rating (2,650 lbs. vs 5,508 lbs.), hence the need to use six rocket bottles to accelerate this heavy fighter rather than the usual two. Burn duration is well in excess of the six seconds of the standard SPRD-99 RATO bottles (possibly even up to several minutes) by virtue of the fact that the oxidiser is held in a separate tank, extending the life of the bottles. If the oxidiser was nitrogen tetroxide, no separate ignition system would be required as combustion occurs on contact between the liquid and solid fuels. Nitrogen tetroxide is also safer than other oxidisers as there is no chance of blow-back and is relatively more thermally stable. Unlike standard SPRD-99 bottles, they cannot be jettisoned when their fuel is exhausted, but must be retained within the engine cowlings.

On the other hand, the Firefox may actually employ an altogether different form of rocket propulsion; the same system as was used by the 1957 altitude world-record achieving B.2 WK163 Canberra bomber. The catalytic decomposition of High-Test Peroxide would provide sufficient thermal energy (700+ degrees Celsius at concentrations above 90%) to spontaneously ignite kerosene from the main fuel tanks. This would reduce the types of fuel carried to two and make the rocket engines entirely reusable. The thrust produced by each triple mounting would be in excess of 12,000 lbs. thus making it an attractive power plant to exploit for the controlled, rapid bursts of power observed in the MiG-31.

The panel gaps on the wings and fuselage are designed to accommodate the thermal expansion experienced as a result of kinetic heating when moving through the air at high Mach speeds. The airframe has significant structural improvements over the MiG-25 with a much greater use of titanium alloys and aluminium as well as composites such as carbon fibre.

The variable-geometry wing tips have 65º leading edges and are similar in appearance and function to those seen on the XB-70 supersonic bomber. They serve to increase directional stability during high-speed flight, creating less drag than would result from having to enlarge the vertical stabilizers further to create the same effect. The 20º up position is used for take-off, landing, and subsonic flight up to speeds just below Mach 1. The droop increases to its maximum anhedral position as speed increases up to Mach 3 and above. The wing-tips create 'compression lift' by funneling and compressing the air between them and the ventral air-scoop, keeping the air beneath the wings, producing extra lift and increasing the supersonic lift:drag ratio.

The wing leading-edge notches serve to reduce vortex disturbance.

The wings have a compound sweep, with 65º and 55º leading edges. The forward wings’ high sweep angle allows for a thick wing section to be used so increasing fuel capacity while still providing limited transonic drag. The rear wing sections are thinner and produce less air resistance at supersonic speeds.

The only modification made to pieces was the 'sizing-down' of parts 53983pb01 (Engine, Very Large Turbine), i.e. the removal of the outer rim in order to fit the turbines into their cowlings. Although they give a very realistic look, they proved very problematic as they restricted the size of the internal weapons bay. In the end I resorted to further cutting (this time of the inner rim) to allow the required degree of recessing of the missiles. Alternatives that perhaps could have been used are the Duplo Airplane Large Engine Fan, part 52923 (but attachment would prove difficult), or Propeller 7 Blade 6 Diameter, part 87751.

Four MegaBloks 2x2 45 degree slopes were used in favour of Lego parts 3043 purely because they provided a shinier surface.

Insulation tape was used on the canopy to black out areas that should in 'reality' be frames or fuselage. Tape was also used to provide the missiles with further detail.

Additional photographs of a slightly earlier version can be seen at

Sources of information:
Kurt Beswick's;;; http://;;;;


 I made it 
  March 19, 2014
Quoting david drake Love the MOC and the extensive write-up. Also just noticed that the view from above makes the Firefox look a bit similar to a Klingon Bird of Prey...
Thanks for praise. Yes, I suppose it does a bit! I tried to explain every detail possible, but no doubt I missed something...
 I like it 
  March 19, 2014
Love the MOC and the extensive write-up. Also just noticed that the view from above makes the Firefox look a bit similar to a Klingon Bird of Prey...
 I like it 
  February 17, 2014
Looks great. Your missiles look good and I like your engine details.
 I like it 
  January 3, 2014
Awesome! I'll have to check that out!
 I made it 
  January 3, 2014
Quoting clayton Marchetti I loved the Firefox movie I even read the book and the sequel Firefox down. This is just fantastic! Where did you find all that info about the aircraft? The missiles look perfect. I love the air intakes and the shape of the wings! Great work on the landing gear. Excellent!
Thanks, glad you like it! You may also like EXEPLARINC's larger version (a long-distance collaborative effort). I grew up in the '80s and became obsessed with weapons systems and the Cold War. "Firefox" fitted into my interests very well! Kurt Beswick's website and e-mails were an invaluable reference as were the details in the books. I did a lot of searching and reading around the internet about hypersonic flight and used these concepts to explain some of the design features seen on the aircraft model. Eastwood and his model-builders did some fantastic work theorizing how a hypersonic stealth plane would look and came up with a brilliant fusion of theoretical and known concepts. The Firefox's faceted nose ended up being remarkably similar to the "Skunk Works"'s still secret F117A's!
 I like it 
  January 2, 2014
I loved the Firefox movie I even read the book and the sequel Firefox down. This is just fantastic! Where did you find all that info about the aircraft? The missiles look perfect. I love the air intakes and the shape of the wings! Great work on the landing gear. Excellent!
 I like it 
  December 5, 2013
Very cool!
 I like it 
  November 29, 2012
Awesome planes! I love the playable creatures such as the rockets!
 I like it 
  November 29, 2012
now this is cooL!
 I like it 
  July 18, 2012
Love the movie, love this creation. Eastwood is such a legend, your version is quirky and I like him. As you say below minifigs are completely out of scale. The Firefox is Awesome, I can’t believe you have crammed in so many details. I love the rear end/engine area especially the air intake (with the turbine behind). Thanks for your kind comment by the way :D
 I like it 
  July 16, 2012
Great MOC, but my scoring still stands.
 I made it 
  July 7, 2012
Quoting Zach Jones that thing just looks scary, and its not even real! It kind of looks like the nightraven from G.I.Joe. do you see it. . . .?
Yes, I am sure that the Firefox was the inspiration behind Cobra's Night Raven. The nose design was uncannily close to the (then yet to be unveiled) F-117A. The prototype MiG-7.01, MiG-1.42 and China's J-20 all seem to have elements of this fictitious 1980's plane. Funny how fiction has become reality!
 I like it 
  July 7, 2012
that thing just looks scary, and its not even real! It kind of looks like the nightraven from G.I.Joe. do you see it. . . .?
 I like it 
  July 2, 2012
WOW Im speechless at the detail...
 I made it 
  March 30, 2012
Quoting John Stahlman Love this! Firefox was my favorite movie as a kid. "Think in Russian!"
Thanks for all the kind comments!
 I like it 
  March 30, 2012
Love this! Firefox was my favorite movie as a kid. "Think in Russian!"
 I like it 
  March 27, 2012
Man! I've been missin out on this! I love your plane! I love the missiles! The overall shape of is superb! I also love the half exposed intake fans! Great plane! 5/5
 I made it 
  January 23, 2012
Quoting Lego 4 Life It's just.....Awesome!
You are very kind. If you like this, wait until you see EXEPLAR INC.s 1:24 version!
 I like it 
  January 23, 2012
It's just.....Awesome!
 I made it 
  January 19, 2012
Quoting The Lego Animal (Jay Rhum) How come you've got so few votes for that beautiful awesome plane!
Thank you for the kind remark. There are a lot of very good MOCs out there so I am not going to take it too much to heart!
 I like it 
  January 18, 2012
How come you've got so few votes for that beautiful awesome plane!
Marty Fields
 I like it 
Chris Melby
  January 8, 2012
I remember those mini-fig's from way back. Nice build!
 I made it 
  January 8, 2012
Quoting Chris Melby I remember those mini-fig's from way back. Nice build!
Thanks. Those original minifigures are actually shorter than the current ones. They are useful still as without arms (or at least without ones that stick out) they can fit into tight spaces like a cockpit!
 I made it 
  June 11, 2011
Quoting EXEMPLAR INC Some constructive criticism: the wing profiles need reshaping to look more authentic... a relatively easy modification I suspect, and lose the fire and external missiles. My version is bang-on in terms of proportions
Thanks for the critique. The wings were a pain. I was aiming for a trailing edge that had the correct angle. I think I achieved that, though no working flaps. The change in angle of the cranked wing should occur in line with the drone pods, but the plate angles available do not create quite the right point of intersection-sorry! The landing gear is correctly positioned; close to the intakes. What might look a bit out is the length of the engines projecting beyond the wing root. This is a result of my unusual choice of parts for the engine cowlings. The wing tips align with the exhaust nozzels as they should and are able to change angle (as seen in the XB-70). The forward fuselage is a bit narrow, I admit, but there seems to be no way around this without sacrificing its overall look. I have spent over 18 months tinkering with aspects of this model (and about £100!) trying to match the plans as closely as possible-even my wing panel junctions match many of those marked. The flames were just to emulate the scene where the engines were given full-throttle when the MiG was being quickly taxied out of the hanger before the doors shut. The external missiles were a nod to their being mounted on the wings in the novels. I tried my best-I can do no more...
  June 11, 2011
Hey Marty: great build and attention to details. Love the swivel missiles, full-size turbines, and tilt front fins. Some constructive criticism: the wing profiles need reshaping to look more authentic... a relatively easy modification I suspect, and lose the fire and external missiles. My version is bang-on in terms of proportions, but it looks like I'm going to have to build another larger version that accommodates full-size turbines like yours... Dare I say I need your help with the cockpit glass, the stars, the... I can't bear to think of the cost... well you get the idea. Contact me at
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  May 26, 2011
Probably the MOC I prefer in your ones! Hey, Marty, Titan is finished now, with my 2 last updates...(V5.2) Please come and see the new pics: dual propeller system and redesigned rudders! Thank you for the suggestion! :-)
 I made it 
  April 29, 2011
Quoting Jay Rhum I love the futuristic design! :-)
Thanks! The design credits, however, must go to Clint Eastwood and his production team. They looked at the most advanced planes of the time such as the SR-71 (with its black anti-radar "iron-ball" paint) as well as experimental designs such as the F-16XL (with its cranked-arrow wing) and XB-70 (with its canards and variable angle wing-tips). They also looked at Pyotr Ufimtsev's work on irregular angular surfaces and their affect on reflecting radar beams. While at college in 1986, I remember being told by a physics colleague that the large flat sufaces on the fictional MiG-31 would not be at all stealthy and would produce a large radar signature. Well, the F-117A, revealed to the public in 1988, proved how clever the production team were in producing a fictional plane whose design concepts were both realistic and so ahead of its time. Well done to them for creating the best fictional plane on film!
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  April 22, 2011
What a plane! It was making me dreaming when I was a child! very well done! I love the futuristic design! :-) Could you please come and check my sub too?
 I made it 
  April 13, 2011
Quoting De Tomaso Pantera This is incredible! I love the film, mix it with the love of lego and the results are staggering. I love everything about this model, congratulations on a superb build. The minifig i so cool!
Thank you for the compliments (blush)! I have yet to attempt automobiles. Your creations are equally impressive.
 I like it 
  April 13, 2011
This is incredible! I love the film, mix it with the love of lego and the results are staggering. I love everything about this model, congratulations on a superb build. The minifig i so cool!
 I made it 
  December 26, 2010
Quoting Joshua Ciesielski This is one of the most perfect rendering of a plane, fictonal or otherwise, I have ever seen. Nice work , sir! And thank for the comment on my F-35B. Yes the weapon bays are a pain in the keister.
Thank you for the very kind comments. All your models are also exceptionally detailed and you did not have to resort to cutting like I did! Those double clips I used for the weapons bay launch rails have a tendency to break, so if you ever consider using them, do take care...
 I like it 
  December 25, 2010
Marty, Marty, Marty. This is one of the most perfect rendering of a plane, fictonal or otherwise, I have ever seen. Nice work , sir! And thank for the comment on my F-35B. Yes the weapon bays are a pain in the keister.
 I like it 
  December 5, 2010
I like "Firefox" too and you build it really outstanding. I like all the detail you give to it. I also build an aircraft "FFR-41MR/FRX-00 Mave" : Please have a visit if possile.
 I made it 
  November 24, 2010
Quoting john lamarck :-)
Thank you very much for reviewing my "Firefox". It was your effort that inspired me to build my version. I had never been motivated to build anything of my own creation when I was young. You showed me what could be achieved, and having always been a fan of the fictional MiG-31, I thought building an accurate scale model would allow me to explore and challenge my building skills to the limit. I will never build anything like it again, but it was an enjoyable project and I am flattered that you like the result.
 I like it 
  November 24, 2010
Marty Fields
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Bob Cleaner
  October 28, 2010
good but whats with the weird guy?
 I made it 
  October 28, 2010
Quoting Bob Cleaner good but whats with the weird guy?
The proportions of minifigures are more akin to that of someone afflicted with dwarfism i.e. head large for body, short legs, compact torso. As Mitchell Gant was portrayed by a 6'4" tall Clint Eastwood, to have him represented by a normal Minifigure would seem silly and, more importantly, would not accurately scale with the aircraft. The old-style figure has, therefore, been stretched my 2 1/3 brick heights (2 2/3 if you include the base plate). The hinge brick allows the figure to sit comfortably in the seat, minus his very long legs of course!
 I like it 
  September 27, 2010
Awesome! I really liked the movie and this impressive fighter. You did a really good job on reproduceing the Firefox and loaded it full of details. Very well done!
 I like it 
  September 21, 2010
A really convincing rendition of the plane. Good sense of humor too. The duct, cowling and intersection with the wing is really impressive.
By Marty Fields
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