Exceptional Performer…if the Stories Are True – The MiG-31 “Firefox”

April 1, 2022

When the Soviet Union revealed the MiG-25 interceptor in 1967, it sent a shock wave through Western Air Forces. For the first time since the beginning of the Cold War, it appeared that the Soviet Union had built a fighter vastly superior to Western contemporaries.


This triggered the United States to thoroughly review its current fighter aircraft requirements, which in turn led to the development and fielding of the F-15 Eagle, the most capable aircraft of its time, in in 1976.

The same year, a MiG-25 defected to Japan, allowing Western experts to examine the aircraft for the first time. They found that the MiG-25 was in fact a far more limited design than had been thought.


Ironically, that concern now left the Soviet Union at a disadvantage. Their existing aircraft were inferior to the American and projected European designs and they were the ones now needing to catch up.

They had begun aircraft projects that would ultimately lead to the MiG-29 and the Sukhoi Su-27, but these were broadly matches for the new Western fighters coming into service. What the Soviets wanted was to create an aircraft that firmly put all others in the shade as air superiority fighters.

They also wanted an aircraft that was capable of intercepting SR-71 Blackbird’s overflying the Soviet Union on reconnaissance missions.

This all led to the genesis of an aircraft that is somewhat mysterious and with which, if the legends are to be believed, the Soviets really pulled all the stops out on.

The MiG-31 Firefox.

Now it is important not to confuse this aircraft with the later MiG-31 Foxhound, an updated version of the MiG-25.

The Firefox was, if the rumours are even partially correct, a far more formidable aircraft.

I should point out that much of the data available on this aircraft is based on stories and unverifiable claims; the Soviet archives, in the short period they were open to western historians, have very limited available reference material.

Development began in the early 1970s with the intention of building an aircraft utterly superior to anything then flying or else projected to fly. And, if the information available is to be believed, they would have been.

The design was far from conventional. The Firefox had a cranked arrow delta design, with canards just aft of the cockpit for improved manoeuvrability.


Additional features were the distinctive downwards bent wing and unmistakable chisel nose which housed the radar. These apparently were measures to improve the aircraft’s stealth capabilities, alongside a reported coating on the outer skin of Radar Absorbent Material.

Further evidence for the aircraft being a stealth design is that the weapons were housed in internal bays that had to be opened to allow engagement of targets, similar to the later F-22 Raptor.

The radar itself is of unknown type, though the two prototypes were said to be fully operational preproduction aircraft. According to information from defectors after the Cold War ended, it was reported to be some form of Synthetic Aperture Array type, which if true would have been a remarkable development for a fighter aircraft of the period.

Actual weapon load is uncertain but is believed to have been made up of six missiles, which would have been R-73 “Archer and R-60 “Aphid” heat-seekers, as well as R-23 “Apex” semi-active radar guided missiles.


It seems likely that had the Firefox reached service, it would also have carried later Soviet missiles such as the R-27 “Alamo” and the R-77 “Adder” active radar homer. The missile component was backed up with a twin 23mm cannon.

The Firefox also had another remarkable development, one that all the available sources agree was a feature – rearward firing defence and countermeasure pods. Note the use of the term “defence”. These pods didn’t just dispense flares and chaff, they also discharged explosive charges.

The concept seems to have been an evolution of the AG-2 Aerial Grenades that were used on earlier Soviet ground attack aircraft, and which I covered as best I could in my previous video on the Il-20.

However, while AG-2s are credited with destroying some enemy fighter aircraft that were attacking Soviet aircraft, it seems vanishingly unlikely that such a weapon would be of any use against another fighter aircraft.

For starters, nothing but another Firefox would, apparently, have had the performance to pursue the aircraft in the first place. And second, in a twisting dogfight, the chances of the targeted pilot being able to gauge correctly when best to release the charge would be impossible.

It seems that the charges would have only been of any potential use in knocking out missiles homing in on the aircraft.

While the actual effectiveness of the Firefox’s stealth measures are subject to debate, the actual construction material is not. The MiG-31’s airframe was composed mostly of titanium, with some less critical components made of a steel/nickel alloy.


This was necessary as the aircraft could reportedly reach staggeringly high speeds.

Though it is unconfirmed, the best sources available state that the Firefox had a cruise speed of between Mach 3.8 and 5.2, with a top overall achievable speed of Mach 6! The aircraft could also achieve a maximum altitude of between 85-and-95,000 feet (c25,000m-27,000m).

To deal with the amounts of heat that this sort of flight profile would have generated required the afore mentioned materials used, which acted effectively as a heat sink; though how the Soviets developed an anti-radar coating that could withstand those sorts of temperatures is unknown.

To power such a monster to such speeds, it needed a truly exceptional powerplant. This was composed of two Tumansky RJ-15BD-600 high-bypass afterburning turbojets, which each produced an estimated 50,000lbf in afterburner.


Again, many of the engine components were made of titanium, including the compressor blades, the only substance available that could possibly stand the pressures involved in such exceptional operating levels.

So, in summary the Firefox was reportedly a stealth fighter capable of Mach 6.

But even THIS isn’t the most remarkable thing about the aircraft, as is apparently alleged.

While the Firefox reportedly had a cutting-edge fly-by-wire control system, which would almost certainly be true as such systems were being developed for other Soviet military aircraft, it is also reported to have had some sort of pilot thought interface. This saw the pilot’s helmet fitted with receptors that linked to the aircraft’s central computer system via a data-link.

This allowed the pilot to literally think about what weapon or system he wanted to engage and the aircraft, allegedly, would respond to his very thoughts.

I’ll admit, of all the myths surrounding the Firefox, this I find the hardest to believe.

But I digress.

Construction is believed to have started in the late 1970s and by 1982 it is thought two prototypes were completed for testing. And here things, in a story already full of practically mythical details, become even more fantastical.

Accounts of what occurred vary, depending on the source, but both aircraft were apparently lost during the testing phase and the MiG-31 Firefox was never to see service, instead the MiG-31 designation being assigned to the afore mentioned Foxhound interceptor.

From the best that I have been able to ascertain, it seems that one prototype was lost in a hanger fire, while the other suffered some sort of malfunction during flight testing and was lost. No doubt if the Firefox was as half as advanced an aircraft as is speculated these losses can be attributed to them testing technologies that were beyond the cutting edge.

After all, the reason why technology testbed aircraft exist and can be so dangerous to fly is because, by their very nature, they are pushing the bounds of possibility.

And Firefox certainly did that.

One can only assume that some fatal flaw in the aircraft came to light during testing, no doubt explaining the complete loss of both aircraft, and this loss, combined with the huge investment made in the program, made it an embarrassment – hence the secrecy around the Firefox and the almost complete purging of records on the project.

However, I’d be remiss if I didn’t at least cover some of the more…colourful conspiracy theories that are floating around concerning the Firefox.

For decades now, stories have been told that the Firefoxes were actually destroyed in an act of sabotage conducted by a Western intelligence service. Normally this is attributed to the CIA, but Mossad sometimes gets accused.

Personally, I think it unlikely.

How any Western intelligence agency could manage to infiltrate what must have been one of the most secret and secure installations on the planet of the time – well, that’s just the stuff of thriller fiction.

There is an even more ridiculous conspiracy on the internet that refuses to die that in fact one of the Firefoxes managed to defect to the United States. This is based on a few so-called “eyewitnesses”, and a single poor quality photograph of what is alleged to be a Firefox at an United States Air Force base.


Personally, I think it looks more like a prop from a movie set rather than an actual aircraft.

Regardless of the truth, the Firefox never saw service. But despite that, the legends and myths built up around the aircraft means that its memory is unlikely to die anytime soon.

Truly, it is an “Unforgotten Aircraft”.


Want to watch the movie?


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