During the Cold War, Mikoyan, a significant Soviet-era armaments company, created a great number of noteworthy fighter planes. The MiG-21, MiG-29, and MiG-31 are Mikoyan’s three most famous fighter aircraft.

The MiG-29 is a powerful multirole fighter in the air, but the MiG-31 is a heavy interceptor. The MiG-31 had its first flight in 1975 with a range of almost 3000km, a top speed of Mach 3, and a maximum takeoff weight of 46.2 tons. The fuselage has a length of 22.69 meters, a wingspan of 13.46 meters, and a height of 6.15 meters.

In comparison, the MiG-29 is a medium-sized fighter with a range of around 2,000 kilometers. The MiG-29 had a maximum takeoff weight of little over 20 tons, a length of 17.37 meters, a wingspan of 11.40 meters, and a height of 4.73 meters. The size difference between the two combatants is apparent at a look.

MiG-31’s conception has significant ties to Soviet Russian region. Due to the vast size of the nation during the Soviet period, the Soviet Union required a long-range, quick, and large-carrying interceptor to defend its borders. MiG-25 was the predecessor of the MiG-31.

The MiG-31 is one of the most commonly used fighters in the Russian military at now. Current MiG-31 upgrades include the D-30F6M engine, digital flight control, a cathode ray tube cockpit display with several functions, and other new Function. Russia is planning to deploy the MiG-31 into the 2030s. Russia is in the process of creating a supersonic interceptor to replace the MiG-31, also known as the MiG-41 or PAK DP.

MiG-31 Foxhound equipped with an R-37 AAM

According to current estimates, PAK DP will have a maximum speed between Mach 4 and Mach 4.3 and a cruising speed around Mach 3. How PAK-DP will use weapons in the future has also been a matter of discussion. Former commander of the Russian Aerospace Forces, Victor Bondarev, said that the MiG-41 would carry R-37 long-range air-to-air missiles “and fresh new Missiles.” The R-37 air-to-air missile has a range of 400 kilometers. In addition, the MiG-31 can carry air-to-air missiles with a modest range. The R-77 has a range of 110 kilometers, but the MiG-31 typically carries four passengers. The Zaslon-M radar can identify big and medium-sized aircraft at a range of 400 kilometers, enhancing the R-37’s launch capabilities in terms of speed and range.

Why does Russia favor MiG-31?

Russia has the world’s biggest landmass. To police its vast borders, Russia need powerful interceptors in terms of hardware. The majority of traditional “light” or even medium-sized fighters presently in service in Russia are incapable of performing this mission due to a lack of intercept range and speed. For instance, the MiG-29 has a range of fewer than 2,000 kilometers, making long-distance expulsion unfeasible. And interception missions, for which it is difficult to swiftly rise and intercept American supersonic bombers without sufficient power, but the MiG-31 is capable of doing so.

Russia is now experiencing a terrible foreign invasion. American strategic bombers often conduct transit surveillance over Russia. Mid-October of this year, American B-1B bombers breached the Russian naval training area, prompting the Russian troops to withdraw immediately. MiG-31 evicted the B-1B. It is evident that the MiG-31 has superior emergency reaction capabilities compared to other aircraft.

Due to its spacious fuselage, the MiG-31 is not only able to execute its customary duties well, but it can also incorporate new weaponry and release fresh vigor. Hypersonic weapon designed specifically for the MiG-31 by Russia is a striking example.

MiG-31k with hypersonic Kinzhal cruise missile

No replacement for the MiG-31

With the advent of multi-path fighter planes and aerial refueling, the worldwide market for heavy interceptors such as the MiG-31 has decreased. But Russia is different. Russia considers the danger posed by the United States to be the greatest, particularly the US strategic bomber and surface fleet. Therefore, for Russia, the MiG-31 is not an added bonus in the struggle against the United States, but rather an essential component.

Even if the Su-57 and Su-35S have started to be delivered and even placed into service in batches, the Russian Air Force still has a significant capability gap. In addition, Russia faces threats from numerous directions, including the north, south, west, and east. These multirole fighters of the newest generation are insufficient to handle the situation alone. The MiG-31 can accomplish Russia’s high-intensity cruise mission, especially along the northern frontier, where Russia faces increased threats.

The MiG-31 has its own distinctive qualities, and the Russian military recognizes its air dominance. Even though it is occasionally observed that Russia possesses both Su-35S and Tu-22M3 supersonic bombers, the MiG-31 is still a “mystery killer” that may be deployed at any moment, instilling dread in the adversary.

Why doesn’t the United States produce a MiG-31-like interceptor?

When the Soviet Union designed the MiG-31, it confronted a danger that the United States did not face. In the mid-1970s, the Soviet Union faced three enormous threats: the SR-71 Blackbird, cruise missiles, and low-flying aircraft, particularly in reaction to the SR-71. Therefore, the Soviet Union has always maintained a high-speed interceptor presence. As a result, the United States does not have a fixed requirement for MiG-31 aircraft.

Russia has a far larger geographical area than the United States. Soviet Russia cannot satisfy its air defense requirements with standard fighter aircraft. And there are insufficient air bases for standard aircraft to cover all of its boundaries. The MiG-31 can cruise at Mach 2.3 for an extended period of time, allowing four aircraft to patrol and defend a vast region against bombers and cruise missiles. The United States, on the other hand, has completed border defense via the building of more military facilities and the deployment of additional fighter planes.

Why does Russia not construct new air bases? This also relates to Russia’s geographical environment. Numerous locations in the north are very frigid and unsuitable for the building of airbases.

The United States argues that the MiG-31 is not a high-performance fighter and that its role is too specific. It is only logical that the United States does not produce heavy interceptors, given that this is inconsistent with the American equipment development philosophy.

Then why isn’t the MiG-31 for sale?

This has to be separated into internal and external causes.

It is feasible for a supersonic interceptor such as the MiG-31 to be labeled as a non-sale product and to have a significant impact from inside Russia.

Internationally, not all nations are as huge as Russia, and their topography and climate are not as complex as Russia’s, thus the need for purchasing is low.

Mikoyan, as an important arms manufacturer during the Soviet era, produced a large number of world-renowned fighter jets during the Cold War. The MiG-21, MiG-29 and MiG-31 can be said to be the three most well-known fighters of Mikoyan.

Specifically, the MiG-29 is an air superior multi-role fighter, while the MiG-31 is a heavy interceptor. The MiG-31 first flew in 1975, with a range of more than 3000km, a maximum speed of Mach 3, and a maximum take-off weight of 46.2 tons. The size of the fuselage is 22.69 meters in length, 13.46 meters in wingspan and 6.15 meters in height.
In contrast, the MiG-29 fighter is a medium-sized fighter with a range of only about 2000km. The MiG-29 has a maximum take-off weight of only more than 20 tons, a length of 17.37 meters, a wingspan of 11.4 meters, and a height of 4.73 meters. The two fighters are placed together, and the size is clear at a glance.
The birth of MiG-31 has a lot to do with Soviet Russian territory. Because of the large area of ​​the country during the Soviet era, the Soviet Union needed a long-range, fast, and large-carrying interceptor to protect the borders of the Soviet Union. The MiG-31 was developed from the MiG-25.
The MiG-31 is currently one of the most widely deployed fighters in the Russian army. The current upgraded version of the MiG-31 uses the new D-30F6M engine, digital flight control and multi-function cathode ray tube cockpit display and other new Function. Russia is preparing to put the MiG-31 into service until the 2030s. Russia is currently developing a supersonic interceptor to replace the MiG-31, also known as the MiG-41 or PAK DP.
MiG-31 Foxhound with R-37 AAM
According to current guessed data, PAK DP will have a maximum speed of Mach 4 to 4.3, and a cruising speed of approximately Mach 3. What kind of weapon PAK-DP will use in the future has also become a topic of interest. Victor Bondarev, former commander of the Russian Aerospace Forces, said that MiG-41 will carry R-37 long-range air-to-air missiles “and brand new Missiles”. The range of the R-37 air-to-air missile can reach 400km. In addition, the MiG-31 can also carry medium-range air-to-air missiles. The R-77 has a range of 110 kilometers, and the MiG-31 can usually carry four. The R-37’s launch capability in terms of speed and range benefits from the Zaslon-M radar, which can detect large and medium-sized aircraft over 400 kilometers.
Why does Russia like MiG-31?
Russia has the largest land area in the world. In terms of hardware, Russia needs heavy interceptors to patrol its huge borders. Most of the conventional “light” or even medium fighters currently in service in Russia are unable to perform this task because they lack the range and speed to intercept. For example, the MiG-29 has a range of only 2,000 kilometers or less, and it is impossible to complete a long-distance expulsion. And interception missions, and if the power is not enough, it is impossible to quickly climb and intercept American supersonic bombers, and the MiG-31 can do it.
At present, Russia is still facing severe foreign invasion. American strategic bombers often approach Russia for transit reconnaissance. In mid-October this year, American B-1B bombers broke into the vicinity of the Russian naval exercise area, and the Russian army did not hesitate to move out. The MiG-31 expelled B-1B. It can be seen that in an emergency, the MiG-31 has an emergency response capability that other fighters cannot match.
The MiG-31 can not only perform its traditional tasks efficiently, but also because of its large fuselage, it can also integrate new weapons and burst out new vitality. Russia’s tailor-made dagger hypersonic weapon for the MiG-31 is a stark example.
MiG-31k with Kinzhal hypersonic cruise missile
No fighter to replace the MiG-31

With the multi-path design of fighter jets and the development of aerial refueling, in fact, the international demand for heavy interceptors such as MiG-31 is not so strong. But Russia is different. Russia regards the threat from the United States as the most significant threat, especially the US strategic bomber and surface fleet. Therefore, for Russia, the MiG-31 is not an icing on the cake, but an indispensable part of the fight against the United States.
Although the Su-57 and Su-35S have begun to be delivered and even put into service in batches, there is still a big gap in the Russian Air Force. In addition, the challenges facing Russia come from multiple directions in the north, south, west, and east. These new-generation multi-role fighters alone cannot cope with it. Especially at the northern border, Russia is facing increasing threats, and the MiG-31 can complete Russia’s high-intensity cruise mission.
The MiG-31 has its own unique characteristics, and the air superiority formed is widely recognized by the Russian army. Therefore, although sometimes it is seen that Russia not only has Su-35S but also Tu-22M3 supersonic bombers, but MiG-31 is still like a “mysterious killer” dispatched at any time, making the enemy fearful.
Why doesn’t the United States build an interceptor similar to the MiG-31?
When the Soviet Union made the MiG-31, it faced a threat that did not exist in the United States. In the mid-1970s, there were three huge threats to the Soviet Union: the SR-71 Blackbird, cruise missiles, and low-flying aircraft, especially in response to the SR-71. Therefore, the Soviet Union has always maintained the presence of high-speed interceptors. This pressure is much smaller, so the United States has no rigid demand for MiG-31 aircraft.
The United States has a much smaller land area than Russia. Soviet Russia cannot meet its air defense needs by relying on normal fighter jets. And there are not enough air bases to fully cover its borders with ordinary aircraft. The MiG-31 can cruise for a long time at Mach 2.3 (cruising speed), which allows four aircraft to patrol and protect a really wide area from bombers and cruise missiles. The United States, on the other hand, has used the construction of more military bases and the deployment of more fighter jets to complete the protection of the border.
Why doesn’t Russia build more air bases? This is also related to the geographical environment of Russia. Many places in the north are freezing cold, and it is not suitable for the construction of airbases.

The United States believes that the MiG-31 is not a high-performance fighter, and its mission is relatively too single. This is not consistent with the development concept of American equipment, so it is only natural that the United States does not manufacture heavy interceptors.
So why is the MiG-31 not for sale?
This should be divided into internal and external reasons.
From within Russia, a supersonic interceptor such as the MiG-31 has a huge effect, and even has a certain strategic role, and it is possible to be designated as a non-sale product.
Internationally, not all countries are as large as Russia, and they are not as complicated as Russia’s geography and climate.
In summary, the MiG-31 is indeed a very good weapon for Russia to deal with US air and sea targets.