SOURCE: THE DRIVE
Recent videos from Russia indicate that the country may be on the verge of introducing significant new air-to-air missile capabilities to its most advanced combat jets. One clip shows a Su-57 Felon advanced combat jet carrying one, or perhaps two, new variants of the R-77 medium-range air-to-air missile family, while another shows a Su-35S fighter jet, the latest variant of the Flanker series, test-firing a very-long-range R-37M long-range air-to-air missile.
The footage of the Su-57 with the K-77s was contained within a recently released official documentary commemorating the 100-year anniversary of the founding of the 929th Chkalov State Flight-Test Center at Akhtubinsk. The video of the Su-35S firing the R-37M emerged in an official Russian Ministry of Defense video marking the same occasion late last week. This center is responsible for the state evaluation of military aircraft, including determining which air-launched weapons are cleared for frontline service.
In the first documentary, seen below in full, four Su-57 fighters are seen flying in formation at one point. One of the jets is carrying external weapons, including what may be two new versions of the medium-range R-77, which has the NATO reporting name AA-12 Adder. The second aircraft in the formation appears to be carrying an improved version of the R-77, the K-77M, also known as Izdeliye 180, under its left wing, while under the right wing it may carry an example of the ramjet-powered Izdeliye 180-PD.
The lack of the basic R-77’s characteristic “lattice” fins at the rear of both the missiles indicates that they are different versions of the weapon, but exactly which models the Su-57 is carrying is not entirely clear.
Russia first began the development of the original active-radar-guided R-77, also known as the Izdeliye 170, back in the early 1980s as a counterpart to the U.S. AIM-120 AMRAAM. It did not enter service before the collapse of that Soviet Union, only becoming part of Russia’s arsenal in 1994.
An improved R-77-1, Izdeliye 170-1, was subsequently introduced on Russian Flanker fighters and has been noted on combat operations during the air force’s operations in Syria. This weapon offers improved resistance to countermeasures, a more sensitive seeker, and aerodynamic refinements — the lattice fins at the rear are retained.
While the R-77-1 was viewed as an interim upgrade, the K-77M is the next stage in the development of the missile, with conventional control fins allowing internal carriage in the Su-57’s weapons bay. Doing away with the old grid fins not only permits internal carriage but also reduces the missile’s aerodynamic drag and radar cross-section.
Other changes include a new dual-pulse rocket motor and a further enhanced radar seeker. The dual-pulse engine ensures that thrust output is maintained throughout the missile’s flight profile, allowing improved high-altitude maneuvering, extended range, and enhanced endgame performance. Unconfirmed reports suggest that the K-77M offers double the range of the R-77; that would imply a range of up to 100 miles for the new weapon.
Vympel has claimed the K-77M will be superior to the AIM-120C-7 AMRAAM and equal to subsequent AMRAAM developments — presumably, the AIM-120D. The manufacturer has also claimed the new weapon is capable of engaging anti-aircraft missiles fired at the launch aircraft, even missiles approaching from the rear.
It’s important to note that although the K-77M was designed for the outset to be carried inside the Su-57’s internal weapons bay, Russian doctrine evidently sees a requirement for external stores in at least some situations. In a high-threat environment, fighting against a peer foe, it would be expected that the Felon carries its weapons internally, to reduce its radar cross-section. However, in less-contested environments, or in the latter stages of a conflict, after enemy air defenses have been suppressed, additional stores could be carried underwing. These might include external fuel tanks and other stores that might not fit in the weapons bays.
Russia is developing other air-to-air missiles that the Su-57 could carry internally, as well. This includes the Vympel K-74M2, or Izdeliye 760, intended for deployment from the aircraft’s internal “quick launch” weapons bays. This may, or may not be, the previously unseen compact weapon, pictures of which first emerged in November 2019. You can read more about these developments in these past War Zone stories, respectively.
For external carriage on the Su-57, and offering yet greater range than the K-77M, there is the secretive Izdeliye 180-PD, in which the suffix stands for Priamotochnyi Dvigatel, or ramjet engine in Russian. This is pitched as a Russian counterpart to the pan-European MBDA Meteor air-to-air missile and utilizes a combined rocket-ramjet powerplant. Reportedly developed as a private venture by Vympel, it’s unclear if the weapon has been ordered by the Russian Aerospace Forces.
Deployment of a rocket-ramjet air-to-air missile would be a significant boost for the Russian Aerospace Forces. In contrast to a normal rocket motor, this type of propulsion allows the missile’s engine to be throttled during different phases of flight, ensuring a high-energy state during the terminal attack phase. You can read more about the specific advantages of ramjet missiles in this War Zone article.
Previous images of the ramjet-powered Adder have been limited to mock-ups at arms exhibitions and unofficial artist’s impressions. As such, the available video evidence is insufficient to determine whether the Su-57 is carrying an example of the Izdeliye 180-PD and one K-77M, or two K-77Ms, or potentially other derivatives of the weapon.
Evidence in favor of the Izdeliye 180-PD includes what appears to be a ramjet air intake under the weapon furthest from the camera. However, the quality of the video is such that this could be a distorted view of one of the stabilizing fins on the missile’s center section.
The other video footage that emerged recently, seen below, shows apparent trials of the very-long-range R-37M launched from a Russian Aerospace Forces Su-35S fighter, with the bort number “52 Red.” Previously, the R-37M was only known to be carried operationally by the MiG-31 Foxhound heavy interceptor and the weapon itself was very rarely seen.
The missile is seen launched from a mid-wing pylon under the right wing of the Flanker, apparently using a trapeze-type ejector. According to Russian accounts, the Su-35S can carry a maximum of four R-37Ms: two under the wings and another pair below the fuselage.
The heavyweight R-37M — known to NATO as the AA-13 Axehead — has a long and protracted history. A product of the prolific Vympel design house, which is responsible for all current Russian air-to-air missile (AAM) families — the program dates back to the early 1990s when it began life as the R-37, intended to arm the Foxhound in its much-improved MiG-31M version.
An example of the original K-37, also known by the in-house designation izdeliye 610, was first launched from a MiG-31M in 1993, destroying an aerial target at a range of 142 miles. While K-37 tests were successfully completed early the following year, the demise of the Soviet Union meant the improved MiG-31M was canceled as a cost-saving measure, together with its planned armament.
However, with subsequent plans to upgrade in-service Foxhounds to MiG-31BM standard, the K-37 program was revisited at the beginning of the 2000s.
Development now focused on the enhanced K-37M/R-37M, or Izdeliye 610M. The revised missile was first launched from a MiG-31 in 2011 and completed its service trials in early 2014 before entering production.
As well as the MiG-31BM that is its primary launch platform, the 13-foot-long R-37M has long been associated with the Su-35, but it seems it was first launched from a Flanker variant this year. In April 2020, a report from the Russian newspaper Izvestia stated that Su-35S fighters had begun captive-carry flights with the R-37M, with test launches to begin later this year. The weapon has also been marketed as an option for the MiG-35 Fulcrum fighter, although this aircraft has yet to enter frontline service in Russia or anywhere else, as you can read about more in this past War Zone piece.
Clearly, the R-37M is intended to engage targets at a prodigious range and, in the past, Western analysts have suspected the weapon was tailored to defeat airborne early warning and control (AEW&C) aircraft and other high-value assets. However, since the R-37M was developed to serve as the primary armament of the MiG-31 interceptor, it should be capable of engaging a wide range of targets, including low-flying cruise missiles.
By way of comparison, the MiG-31’s original R-33 AAM can destroy targets out to a range of 68 miles. The furthest-flying version of the U.S. AMRAAM, the AIM-120D, is thought to have a range of up to 100 miles, although official performance numbers are classified.
In the past, Western observers have suggested that an ultra-long-range version of the R-37M would be developed, with a jettisonable rocket booster increasing the range up to almost 250 miles, although there’s no evidence of this, and it may result from confusion with the rival Novator K-100 missile, or Izdeliye 172S. Nearly 20 feet long, this weapon attracted no little interest when shown in public in the early 1990s and ultimately lost out to the K-37.
According to data from the manufacturer, the R-37M, at least in its RVV-BD export form, can defeat “some types” of aerial targets at a range of up to 124 miles. The qualification here suggests that only larger, and probably less agile, aircraft can be engaged at the outer edges of the missile’s flight envelope. As ever, with such “sales brochure figures,” it should be remembered that these likely reflect missile performance in the optimum conditions, and in reality, they will vary greatly depending on the type of engagement and the energy and altitude state of the launching aircraft.
The missile is powered by a dual-pulse solid-propellant rocket motor. It flies toward its target guided by an onboard dual-band active radar seeker, while an inertial navigation system receives mid-course updates from the launch aircraft. During the terminal phase of the engagement, the seeker can lock on to a target with a 54-square-foot radar cross-section at 25 miles or more, the manufacturer claims.
Like the R-33 that preceded it, the R-37M is said to be capable of being armed with a nuclear warhead for destroying larger formations of aircraft or missiles.
Exactly why the Russian Aerospace Forces are choosing to integrate the R-37M with the Su-35S at this point is unclear. It could be that with the MiG-31 increasingly taking on new roles — including air-to-ground missile strike and anti-satellite — the Flanker is expected to play a greater role in long-range air defense. It’s also possible that the work is being driven by hopes of securing export orders of the R-37M to new or existing Flanker operators. In the future, it’s expected that the R-37M will arm the Su-57, too.
Taken together, the videos do demonstrate that Russia is currently working hard to expand the armories of both its current and future fighters, including air-to-air missiles that should be able to out-range current Western counterparts.