Key Points and Summary: The MiG-31 Foxhound is a long-range interceptor that replaced the Soviet-era MiG-25, featuring advanced radar and high-speed capabilities. Originally designed for air defense, the MiG-31 has evolved into a formidable missile carrier.
-The MiG-31K variant now carries the Kh-47M2 Kinzhal, a hypersonic air-launched ballistic missile derived from the Iskander-M. More than 30 MiG-31Ks are in service, with reports suggesting future integration of the Zircon hypersonic cruise missile.
MiG-31. Image Credit: Creative Commons.
-While powerful, these upgrades reflect Russia’s shifting air defense priorities, repurposing Cold War-era aircraft to meet modern warfare needs, particularly in Ukraine and potential future conflicts with NATO.
Can the MiG-31K’s Kinzhal Missile Change the Battlefield?
In the Soviet era, the Air Defense Forces (PVO) were a separate branch of the USSR Armed Forces and operated their own air bases on the periphery of the nation. Their function was to be able to shoot down any aircraft that might threaten Soviet air space, which sometimes resulted in catastrophic mistakes. The most famous of these was the 1983 KAL 007 shootdown of a Boeing 747 commercial airliner near Sakhalin Island in the Russian Far East by a PVO Sukhoi Su-15.
Seven years before, a young PVO pilot named Viktor Belenko sent shockwaves through the military aviation and national security communities by defecting from the USSR in his single-seat Mikoyan MiG-25 interceptor and landing at a commercial airport on the island of Hokkaido in Japan.
Teams of specialists from the United States and elsewhere dashed to Japan to examine the aircraft and its on-board systems. Some of these specialists came away more than slightly underwhelmed.
The MiG-25 had been hyped in US Congressional testimony and elsewhere by intelligence officials as the greatest fighter in the world. It was even described as more than a match for the F-15—the most significant and fastest US combat aircraft in inventory.
Reality proved to be starkly different. The MiG-25 had gas-guzzling turbojet engines that were highly fuel-inefficient and had a short service life. The radar was crude and dangerous to anyone close by if turned on while on the ground. Its missiles were short-range, and most of the avionics were vacuum tube-era designs. Due to the terrible visibility out of the cockpit, the pilot had to be guided into the target by radar operators on the ground.
“This cannot be the best they have,” said one of the USAF engineers sent to inspect the aircraft. “There has to be something else.”
There was.
Enter The Foxhound
The MiG-25 was a program put together somewhat in haste for the PVO to have a counter against the USAF SR-71 Blackbird. The aircraft was pushed into service and was not an elegant product. At the same time, Mikoyan was working on a highly improved aircraft based on the MiG-25 design.
Some of the senior Mikoyan Design Bureau leadership had close relations with the PVO at the time. And, as one of the bureau’s engineers explained to me more than three decades ago, the PVO also wanted an aircraft designed primarily for them.
MiG-31
“Just as your US Navy does not want to buy a fighter designed initially for the USAF, the Soviet PVO did not want to buy only the Su-27, which was built for the Soviet Air Force (VVS),” he said during one of the Moscow Air Show expos.
The MiG-31 was definitely a leap of several levels of capability in more than one aspect. The aircraft had the most sophisticated radar set of its kind in the world. The NIIP Passive Electronically Scanning Array (PESA) N007 Zaslon was the first electronic scanning model flown in a fighter and, in some ways, was more sophisticated than the F-14’s Hughes AWG-9.
Like the F-14, probably its closest US analog, the MiG-31 was a two-seat aircraft with a Radar Intercept Officer in the back seat. The missile it guided was the Vympel R-33 (AA-9), which was to be a mainstay of Russian long-range AAMs for decades as well.
Russian designers I knew at MKB Vympel who designed the missile contrasted the two aircraft’s radar and missile mix combinations—AWG-9 + the AIM-54 and Zaslon + R-33 in the following manner:
“In designing the Zaslon we had essentially come up with the world’s most expensive pistol and then used it to shoot average-priced bullets. The US took an opposite approach. They designed the world’s most expensive bullet – the AIM-54 Phoenix – and then built an average-priced bullet to shoot it with. A real example of two disctincly different approaches to solve the same problem.”
In addition to being built out of far more sophisticated metal alloys, which made it lighter, the MiG-31 also ended up being powered with the best aero-engine that Russian industry had ever designed and one of best fighter engines in the world in its day. The Soloviev D-30F6 engine was not a fuel-hungry turbojet but the first experimental domestic turbofan engine with a mixing-type afterburner.
MiG-31K: TBM Carrier
For more than 40 years, the MiG-31 continued to be improved with more advanced versions of the Zaslon radar, improved R-33 designs, and later the R-37, a generational leap above its predecessor model.
However, the most revolutionary step for the MiG-31 was turning it into a delivery platform for the Kh-47M2 Kinzhal Air-Launched Theatre Ballistic Missile (TBM). This missile is believed to have been derived from the 9K720 Iskander-M ballistic missile design and is launched from a modified MiG-31K. Its original concept was to be a missile that non-360-degree radars would be unable to detect.
MiG-31. Image: Russian state media.
At the end of the Cold War, a considerable number of MiG-31s were put into storage due to the end of the need for intense air defense coverage by interceptor aircraft and the nation’s inability to incur operational costs. These aircraft are now being brought out of storage and modified into the MiG-31K configuration. This change prevents the aircraft from carrying out the air defense mission and turns into this dedicated missile carrier.
More than 30 of these types are now in service with the Russian Aerospace Forces (VKS). There are plans in the works for the MiG-31 to receive new classes of air-to-surface missiles to complement the Kinzhal. This is reported to include an air-launched variant of the Zircon hypersonic cruise missile—the original which began to be fielded by the Russian Navy in 2019.
About the Author: Reuben F. Johnson
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is now an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
