Key Points and Summary – A triple MiG-31 incursion into Estonian airspace rattled NATO capitals and revived a key question: why is Russia’s 1980s Foxhound still frontline?
-Unlike the MiG-25 it replaced, the two-seat MiG-31 added efficient D-30F6 engines and the Zaslon PESA radar, enabling long-range R-33 intercepts and mini-AWACS control.
MiG-31 Fighter. Image Credit: Creative Commons.
-Modernized MiG-31Ks now launch Kh-47M2 Kinzhal missiles, extending standoff reach.
-But Ukraine’s growing success intercepting Kinzhals with Patriot batteries exposes limits to Russia’s “uninterceptable” hype and its reliance on aging airframes.
-The episode underscores a paradox: the MiG-31’s unique speed, sensor range, and weaponry keep it relevant—even as contemporary defenses erode its intimidation value.
The MiG-31 Foxhound Just Won’t Go Away: Here’s Why
The incursion into Estonian airspace by three Mikoyan MiG-31 Foxhound aircraft on September 20 has had repercussions within the individual capitals of the NATO member nations that do not stop reverberating.
Several heads of state of members, including United States President Donald Trump, and foreign ministers of the alliance have not openly called for Russian aircraft committing any such further violations to be shot down by NATO defenders.
However, within the aerospace and defense industrial community, a second-order inquiry is also being discussed.
Specifically, the question is how the MiG-31 remains in service with the Russian armed forces.
It entered service in 1981, preceding other aircraft of the same era, such as the MiG-29 and the Sukhoi Su-27.
MiG-29 Fighter. Image Credit: Creative Commons.
Those other models are almost all retired and have been replaced by other, more advanced derivatives.
Origin Story of MiG-31
The MiG-31 was also originally created for a special mission, specifically as a replacement for the MiG-25.
Both aircraft were developed for the Soviet Air Defense Forces (PVO) during the time that this service branch was separate from the Soviet Air Forces (VVS).
The two services were later merged during the post-Soviet era into what is today the Aerospace Forces (VKO) of the Russian Federation.
The differences between the two aircraft are pronounced.
The MiG-25 was a single-seat high-speed, high-altitude interceptor.
Two powerful Tumansky R-15B-300 turbojet engines powered the aircraft.
The aircraft was not much more than a flying rocket sled, and the pilot had such poor visibility out of the cockpit and such a crude radar that he had to be ground-controlled to intercept (GCI) within visual range of the target.
The Birth of a Modern Air Defense Platform
The MiG-31, every model of which is a two-seat aircraft, was built on the back of the experience of the MIG-25.
The designator for its prototype test bed aircraft was even MiG-25M, and the two airframes bear a resemblance to one another.
MiG-25 Foxbat. Image Credit: Creative Commons.
But they are two very different aircraft in more than one respect.
The MiG-25’s air frame was composed of 80 percent nickel-steel alloy, with 11 percent aluminum and 9 percent titanium.
It was a heavy aircraft that utilized a good deal of welding in its construction. The MiG-31 was far more advanced, as well as lighter—49 percent arc-welded nickel steel, 33 percent light metal alloy, 16 percent titanium, and 2 percent composites.
Two other aspects of the MiG-31 made it a generational leap above its predecessor.
One was the Soloviev D-30F6 turbofan engine, which was far more fuel-efficient.
The other, and most importantly, was the NIIP N007 Zaslon radar set. It was the first passive electronically scanning array (PESA) radar to be mounted in any aircraft.
The radar-equipped MiG-31 can shoot down targets from great distances using the Vympel R-33 long-range air-to-air missile (AAM).
The aircraft could also function as a forward airborne control platform—almost like a mini Airborne Warning and Control System (AWACS).
Breathing New Life Into an Old Platform
What has kept the MiG-31 still in service and still relevant is that the design team at Mikoyan has converted what used to be an aircraft designed to shoot down high-altitude Western strategic bombers into a long-range attack platform.
Some of the fleet have most recently been modified to the MiG-31K configuration.
With these modifications, the aircraft can launch the Kh-47M2 Kinzhal air-launched ballistic missile, which the Russians describe as a hypersonic weapon.
The impact of the aircraft in this configuration has been muted since the war with Ukraine began due to the increasing capability of Kyiv’s air defenses.
The US-made Patriot air and missile defense system has had notable success against the Kinzhal, having successfully intercepted dozens of them. “If the Russian military is relying on this weapon to be effective against its adversaries, then they need to make sure the country being fired on has a less-than robust air defense network,” said a former US Army air defense unit commander who spoke to National Security Journal.
The declining success of the Kinzhal in Ukraine demonstrates, reads a recent essay on the MiG-31, “highlights Russia’s dependence on aging platforms and underscores the limitations of so-called ‘uninterceptable’ systems in the face of modern, adapted, and responsive defenses.”
About the Author: Reuben F. Johnson
Reuben F. Johnson has thirty-six years of experience analyzing and reporting on foreign weapons systems, defense technologies, and international arms export policy. Johnson is the Director of Research at the Casimir Pulaski Foundation. He is also a survivor of the Russian invasion of Ukraine in February 2022. He worked for years in the American defense industry as a foreign technology analyst and later as a consultant for the U.S. Department of Defense, the Departments of the Navy and Air Force, and the governments of the United Kingdom and Australia. In 2022-2023, he won two awards in a row for his defense reporting. He holds a bachelor’s degree from DePauw University and a master’s degree from Miami University in Ohio, specializing in Soviet and Russian studies. He lives in Warsaw.
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John Slep
September 24, 2025 at 11:48 pm
What’s not being mentioned is that it takes a salvo from an entire Patriot battery to reliably shoot down one Kinzhal missile.. Hence when they squared the two off both sides claimed victory.. That’s because the Patriot did shoot down a Kinzhal, however they launched several, and so one penetrated and took out a Patriot battery, protecting Kiev.. All true!