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Threat Analysis: Su-35S

Discussion in 'Modern Warfare' started by layman, Apr 20, 2017.

  1. layman

    layman Aurignacian STAR MEMBER

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    Threat Analysis: Su-35S

    Part - I

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    Image 1: Su-35S

    Author’s Note
    : I had originally planned to release an article detailing a hypothetical engagement between 12 F-22As and 48 Su-35s this week, but decided I needed more time to thoroughly research basic fighter maneuvering and variables associated with within visual range engagements. In the meantime, I will publish a two part series on the Su-35.

    Introduction – Divergent Fighter Generational Definitions & Implications

    Russian publications consistently refer to the Su-35 as a “4++ or 4.75 generation” fighter, rather than a 4+ generation fighter like the Su-30SM, to underscore the additional fifth generation qualities of the Su-35.[1] This assertion is largely reflective of Russia’s divergent conceptualization of fifth generation qualities when compared to the U.S. The U.S. has largely de-emphasized superior maneuverability performance above the fourth generation series as a core component of fifth generation aircraft. The two central qualities which define fifth generation capabilities in the U.S. context are low observability and enhanced situational awareness (SA).[2] In contrast, Sukhoi patent documents detailing the PAK FA’s design trade-offs indicate the Russian Aerospace Forces–the Russian Air Force was reorganized as of August 2015 and is abbreviated as the VKS for Vozdushno-Kosmicheskiye Sily–considers superior maneuverability above the fourth generation series as the dominant fifth generation trait with low observability being an important, but secondary, objective influencing the design.

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    Image 2: Fighter generations. Image Credit: USAF General Hawk Carlisle.[3]

    This conceptual divergence with the U.S. regarding fifth generation fighter characteristics likely reflects the limitations of the Russian defense industrial base as well as historical-institutional preferences among the Russian defense establishment. While the PAK FA and the Su-35 are distinct designs, the Su-35 mirrors the PAK FA in that they both share the same design philosophy of maximizing maneuverability performance. While the Su-35 incorporates a host of additional improvements detailed below, the divergent Russian design philosophy will substantially influence how Russian pilots conceptualize engagements and create new techniques, tactics, and procedures (TTP).

    History

    The Su-35 originated from the rivalry between the Irkutsk and Komsomolsk-on-Amur production plants during the 1990s. Sukhoi’s component companies struggled to survive in the absence of exorbitant Soviet-era defense expenditures and heavily relied upon foreign exports to sustain their industrial base and fund new research and development projects. The leadership of the Komsomolsk-on-Amur Plant decided it needed a design to compete with Irkutsk’s Su-30MKI in the international fighter market; the Russian Ministry of Defense (MOD) did not play an active role in the development of the Su-35.[4]

    The Komsomolsk-on-Amur plant largely failed in its bid to compete with Irkutsk among foreign customers; the Su-30MKI and its derivatives became the most widely exported Russian fighter in the post-Soviet period.[ii] In August 2009, the Russian Air Force ordered an initial batch of 48 Su-35S aircraft for $2.51 billion (the deal also included 12 Su-27SM, 4 Su-30M2 aircraft, spares, maintenance, and $100 million for additional investments in the Su-35’s development); the S denotes the domestic Russian variant of the Su-35.[5] Two factors led to the adoption of the Su-35: (1) the Russian Air Force urgently needed new airframes to replace its aging Soviet-era equipmentand (2) the fifth generation PAK FA faced significant technical and financial difficulties. In December 2015, the VKS placed a follow-on order for 50 Su-35S aircraft worth at least $778 million; deliveries of all aircraft are scheduled to be completed by 2020.[6] While the Su-35S was intended to serve as a gap filler and lower-end complement to the PAK FA–which is also produced by the Komsomolsk-on-Amur Plant–Russia’s ongoing financial difficulties and continued PAK FA program delays ensure the Su-35S will remain the VKS’ high-end air superiority fighter in the short to medium term.

    The current version of the State Armaments Program or GPV-2020 plans for the procurement of 52 PAK FA aircraft by 2020.[7] However, in April 2015, Russian Deputy Defense Minister Yuri Borisov announced the MOD was considering curtailing PAK FA procurement to a single squadron of 12 production aircraft between 2016 and 2020. After the 12 aircraft are inducted into service, the MOD may consider pausing further production of the PAK FA until “until such time as the initial batch of aircraft prove their advertised performance during operational trials”; orders of the Su-35S would be increased between 2016 and 2020.[8][9] Delayed PAK FA production is highly likely as Russia’s defense budget is expected to fall 12% in nominal terms between 2016 and 2018; the actual cut is even larger given the current 6.4% inflation rate in Russia.[10] The Su-35S will be complemented the more numerous multi-role Su-30M2 and Su-30SM which will serve as the air-to-air backbone for both the VKS and Russian Navy into the 2020s and 2030s.[11]

    Airframe Design

    The Su-27’s robust and adaptable airframe provided the basis for development of the Su-35 which features minor airframe modifications such as: thorough use of composite materials to reduce radar cross section (RCS) and weight, inclusion of an electroconductive canopy for further RCS reductions, greater reliance on titanium rather than aluminum alloys compared to the Su-27 (to strengthen the fuselage), removal of the dorsal speedbrake (braking is achieved through differential actuation of the rudders), and improved flight control surfaces.[12][13][14] The use of composite materials, radar absorbent material (RAM) coatings, and an electroconductive canopy reduce the Su-35’s frontal RCS to between 1m^2 and 3m^2 in a clean configuration compared to the Su-27’s 15m^2.[15][16] Aside from the airframe, the most notable distinguishing traits of the Su-35 compared to other Flanker derivatives are its thoroughly modernized avionics and electronic warfare (EW) suite as well as its 3D thrust vectoring NPO Saturn 117S (AL-41F1S) turbofan engines.

    Avionics

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    Image 3: Detection range of N135 in peak power mode against select aircraft. The detection range is significantly reduced when operating in the search mode which would detect an F-35 at 15.6 nautical miles (29 km) and an F-22 at 10 nm (18 km). Image Credit: Colin Throm, AW&ST.

    The Su-35S features the most powerful passive electronically scanned array (PESA) radar of any Flanker variant in service, the N135 Irbis radar (Irbis-E is the export version).[17] The N135 in an evolution of the N011M Bars and features a greater search azimuth of +/-125°, higher resolution, wider variety of frequencies, and greater resistance to jamming.[18] The N135 can detect an approaching 3m^2 target at 199 to 216 nm (350 to 400 km) or a tail aspect target at 108 nm (200 km) while operating in its peak power mode. However, operating in peak power mode would focus radar energy on a single narrow point in space thereby diminishing the radar’s search capabilities. Furthermore, the use of peak power mode would betray the N135’s position to emission locator systems. In effect, using peak power mode to generate target quality track data against a low RCS target at maximum range requires queuing from other sensors or platforms to narrow the N135’s search area. Without input from other sensors or platforms, Su-35S pilots are likely to operate their radars in either the search or track-while-scan modes; the search mode provides detection against 3m^2 approaching targets at 108 nm or 200 km.[19] The OLS-35 infrared search and track (IRST) system could potentially act as the queuing source to narrow the N135’s search radius to gain target quality track information on low RCS targets.
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    Image 4: Sukhoi clearly markets the OLS-35 as a means to defeat stealth aircraft, note the YF-22 (instead of F-22) graphic. Image Credit: Sukhoi.
    The OLS-35 is mounted near the canopy and provides IRST, target designation, and laser rangefinding capabilities. The OLS-35’s can track up to four targets simultaneously across +/-90° azimuth and -15/+60° elevation; the detection range against of tail aspect aircraft is at 30 nm (56 km) and is 19 nm (35 km) against forward aspect aircraft.[20] It is highly like the OLS-35 possesses a mode in which it is slaved to the N135 radar to improve detection against stealthy targets similar to the Su-27’s OLS-27.[21] While the OLS-35 provides greater flexibility to Russian pilots when engaging low observable aircraft, the OLS-35 does not represent a panacea solution against stealth aircraft. Like all IRST systems, the OLS-35 does not provide target quality track data for weapons employment. For example, if a Russian pilot detected an approaching forward aspect F-35 at 15 nm, the Russian pilot could not directly utilize the IRST data to direct semi-active, active, or passive homing missiles; laser illumination capabilities are generally a means to guide air-to-ground munitions rather than air-to-air missiles.[iii] Therefore, the main benefit the OLS-35 provides is enhanced SA at short to intermediate ranges.

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    Image 5: The Su-35 cockpit features two 15 inch multi-functional displays.

    Despite possessing powerful sensors, the extent in which the Su-35’s sensor inputs are fused to provide SA is unclear. The Su-35S’ development process was reportedly delayed as a result of difficulties integrating the Su-35’s avionics.[22] This would be consistent with ongoing difficulties with the PAK FA program which has also struggled to fuse the aircraft’s multiple sensor inputs to generate a coherent view of the battlespace.[23] As with the F-35, modern fighter aircraft provide enormous quantities of raw data, but pilots need actionable information. That is, pilots need to be able to quickly discern information such that they can build a mental picture of the environment which informs there decision making. The faster an avionics suite is able to assist the pilot in building a mental image of the battlespace, the quicker the pilot’s decision making cycle. The software involved in facilitating SA is among the most difficult aspects of designing a fifth generation aircraft. English open source literature on the Su-35’s SA and software is very limited as is literature describing Russian military datalinks.

    cont...
     
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  2. layman

    layman Aurignacian STAR MEMBER

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    Part II - Armament R-27 & R-73


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    Image 1: The Su-35 can accommodate a maximum of 17,637 pounds (8,000 kg) of ordinance mounted on 12 external hardpoints. The Su-35 will be armed with three principal air-to-air missiles (AAMs): the R-27, R-73, and R-77. Note: various Russian sources claim the long-range R-37 will be integrated with the Su-35, but no live fire tests of the R-37 from the Su-35 have been documented at this time. Image Credit: Sukhoi.

    R-27/AA-10 Alamo


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    Image 2: R-27 variants. Image Credit: Artem Company.

    The R-27 is a highly modular beyond visual range (BVR) missile family designed by Vympel–now the Tactical Missiles Corporation–during the late 1970s for use on the Mig-29 and Su-27 fighters; the missile is currently produced by the Artem Company, a subsidiary to the state-owned Ukrainian export firm Ukroboronprom.[1] The R-27 series of missiles can generally be categorized by their diameter, 230 mm for the baseline variant and 260 mm for the “energeticheskaya” or energetic variants which feature a larger warhead, rocket motor, and extended range.[2] All variants have an 8g maneuverability limit and utilize an active radar proximity fuse to activate the missile’s 73/86 pound (33 kg/39 kg) continuous rod warhead. The R-27 is comparatively larger than most medium range BVR AAMs; the “energetic variants” of the R-27 have launch weights between 343 kg to 350 kg which is more than twice the weight of the 161 kg AIM-120D. The weight, wingspan of the “butterfly” control surfaces, and 4.5+ meter length of the extended range series of R-27 limit external carriage to a maximum of six missiles for the baseline Su-27 Flanker and eight missiles for the Su-35.[3][4] Across both the 230 mm and 260 mm variants, there are four principal guidance types: semi-active radar homing (SARH), infrared (IR), passive radio frequency homing (PRFH), and active radar homing (ARH). Detailed descriptions of each method of guidance are described in the notes section at the end of the article.

    The R-27R/RE is the most numerous BVR missile in the VKS inventory and is roughly equivalent to the U.S. AIM-7 Sparrow.[5] The R-27R/RE utilizes an inertial midcourse guidance with radio command updates and a terminal SARH seeker to locate targets. The N135 Irbis is able to illuminate up to two separate targets simultaneously to guide SARH missiles.[6]
    The baseline R-27R variant has a range of 38 nautical miles (70 km) against approaching non-maneuvering targets compared to the R-27RE’s 70 nautical miles (130 km) range.[7] The only confirmed instance in which the R-27R was used in combat was the Ethiopian-Eritrean War in 1998-2000 which will be discussed after the R-73.

    The R-27T/ET series is visually distinct from all other R-27 variants as a result of its IR seeker in the nose section of the missile. While the R-27T/ET is technically a BVR missile from a maximum kinematic range perspective, in practical terms it is limited to within visual range (WVR) engagements. The missile’s 36T seeker must be locked-on to a target before launch as the R-27T/ET does not feature inertial guidance and cannot receive radio command midcourse updates.[8] The R-27ET features an upgraded seeker which provides greater IR countermeasure discrimination performance and has a maximum acquisition range of approximately eight nautical miles or 15 km.[9]

    The R-27P/EP is among the few PRFH AAMs in service. The missile utilizes a passive X-band PRGS-27 (9B-1032) seeker to detect emitting targets from distances up to 108 nm (200 km) away. However, the missile is still constrained by its limited power supply and propellant. Thus, the effective maximum kinematic range against approaching targets is 60 nautical miles or 110 km.[10]Vympel has marketed the R-27P/EP as capable of engaging airborne early warning and control (AWACS) aircraft, stand-off jammers, and fighter aircraft. The R-27P/EP is theoretically able to provide BVR capabilities without alerting adversary radar waring receivers (RWR). However, the missile is constrained in that it requires a cooperative constantly emitting target. The first live fire tests of the R-27P occurred in 1984 and the R-27P entered Soviet Air Force service in 1987. A limited number of missiles were produced prior to the collapse of the Soviet Union by the Artem plant in Ukraine.

    R-27A/AE is an ARH variant of the R-27 family which did not enter production as a result of the development of the more advanced R-77.

    R-73/AA-11 Archer

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    Image 3: R-60 (left most) and R-73 missiles on display at the National Air and Space Intelligence Center, Wright-Patterson Air Force Base, Ohio. Through the “Foreign Materiel Acquisition and Exploitation Program”, the U.S. Government has acquired everything from Russian MANPADS tocomplete S-300V and S-300PMU systems. Image Credit: USAF.

    The primary IR guided missile of the VKS is the R-73 which is fulfills a similar role to the American AIM-9 Sidewinder. The R-73 is slightly larger than the AIM-9X, the R-73M2 has a diameter of 170 mm, a launch weight of 110 kg, a 8 kg warhead, and a length of 2.9 meters. Like the Sidewinder, the R-73 family of missiles contains more than half a dozen variants which vary in terms of seeker type, fuse, off-boresight capability, and rocket motor. The Molniya OKB (design bureau) began work on the R-73 during the 1970s in Ukraine with the intent of developing a more maneuverable successor to the R-60/AA-8 Aphid. Responsibility for designing the new missile was transferred to Vympel in 1979 and the R-73 was first operationally deployed in 1984.[11] The R-73’s capabilities were greatly enhanced as a result of the Shchel-3UM helmet mounted sight which enabled off-boresight shots. U.S. pilots were able to thoroughly examine the capabilities of the R-73 and Shchel-3UM through a series of exchanges with the German Air Force in the 1990s. Lt. Col. Fred "Spanky" Clifton (Ret.), an F-16 pilot who was able to fly the Mig-29 in Germany, explains the Archer and HMS was much more effective than expected:

    The Archer and the helmet-mounted sight (HMS) brought a real big stick to the playground. First, the HMS was really easy to use. Every pilot was issued his own HMS…Being on the shooting end of the equation, I saw shot opportunities I would've never dreamed of with the AIM-9L/M...In the WVR (within visual range) arena, a skilled MiG-29 pilot can give and Eagle or Viper driver all he/she wants.[12]

    Despite the effectiveness of the R-73 and HMS, U.S. pilots generally judged the R-27 was significantly inferior to the AIM-7 and AIM-120. This conclusion was largely made evident a few years later in the Eritrean-Ethiopian War between 1998 and 2000 described later in the article.

    The next major evolution in the R-73’s design is the R-74M which features an improved range of 21.5 nm or 40 km, 60°+ off-boresight capability as well as improved dual-band Impuls IR seeker with extended detection range and countermeasure discrimination capabilities. There are two variants of the R-74M, the R-74ML laser proximity fuse variant and the R-74MK with an active radar fuse.[13] The R-74M entered service in 2012, but the Impuls seeker is manufactured by the Arsenal company in Ukraine meaning Russia’s continued access to new R-74M seekers remains in doubt post-Crimea. Russia has had to launch numerous domestic industry programs to mitigate the loss of Ukrainian defense imports.

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    Image 4: Russia recently undertook a domestic development program to replace the Ukrainian produced Sura-M helmet mounted display for the Mig-29SMT, Su-30SM, and Su-35S.[14]

    The latest variant of the R-73 is the R-74M2 which is analogous to the AIM-9X Block II. The R-74M2 features a Karfagen-760 IR seeker, more accurate internal guidance, datalink, and an improved rocket motor.[15]

    Combat Record R-27 & R-73

    In 1998, the Eritrean Air Force (ERAF) was supplied with an initial batch of six Mig-29s and at least 36 R-27 and 72 R-73 missiles; Eritrean pilots were trained by Ukrainian mercenaries.[16] The Ethiopian Air Force (EtAF) received at least eight Su-27S aircraft, including two Su-27UBK trainers, as well as 80 R-27 and 96 R-73 missiles from Russia between 1998 and 1999. In contrast with the ERAF, the EtAF Su-27s were often flown by Russian pilots.[17][18] Detailed accounts of aerial engagements during the Eritrean-Ethiopian War are sparse. Tom Cooper and Jonathan Kyzer’s article, “Ethiopian Eritrean War, 1998 – 2000”, originally printed in AFM Magazine’s August 2000 edition, is one of the few works to provide detained information regarding the combat performance of the R-27; an expanded version of the article is available courtesy of the Air Combat Information Group. Cooper and Kyzer describe two major engagements during the Eritrean-Ethiopian War in February 1999 and in May 2000 which feature the use of the R-27 and R-73.

    February 1999 Engagement:

    …on the morning of 25 February four MiG-29s were sent to intercept two Su-27s which were patrolling along the front-lines at Badme. Both Sukhois, flown by Ethiopian pilots, detected the appearance of their opponents in time and attempted to disengage, when - all of a sudden - they came under an attack by several R-27/AA-10 missiles. None of the weapons fired by the Eritreans – which were meanwhile inside the Ethiopian airspace – hit, but after evading them, the Ethiopians decided to turn back and fight. The lead, Maj. Workneh, acquired the enemy and fired what was reported as a "salvo" of R-27s, targeting one MiG-29 after the other. However, all the missiles missed and the only result was that the Eritreans were forced to break their attack - only to be pounced by the faster Su-27s. The result of following dog-fight was one Eritrean MiG-29 shot down, probably by an R-73/AA-11 IR-homing, short range air-to-air missile (fired again by Maj. Workneh).[19] [emphasis added]

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    Image 5: Russian Su-27 intercepted by the RAAF, this aircraft is armed with a typical mix of R-73, R-27T, and R-73ER missiles. Image credit: RAF.

    May 2000 Engagement:

    On 16 May 2000 Eritrean Air Force flew couple of counterattacks against the Ethiopian “left hook”, advancing against the western flank of Eritrean positions....at least one MiG-29 was damaged sufficiently to crash-landed at Asmara, obviously after being damaged by R-27. The ERAF remained stubborn: only two days later, two MiG-29s were scrambled to intercept an incoming formation of EtAF MiG-21s. The leading Eritrean pilot missed with his R-27s, but then shot down at least one of Ethiopian fighters, using the 30mm gun during a short dogfight. Nevertheless, only minutes later, the same MiG-29 was in turn intercepted by a pair of EtAF Su-27s. As the Sukhois engaged, one of them collided with an Africa Buzzard (a very large bird), and had to return to base after sustaining heavy damage. The other Sukhoi – flown by one of former Derg-pilots – continued, engaging the MiG and shooting it down by a single R-73.[20] [emphasis added]

    Cooper and Kyzer conclude the R-27 likely had a probability kill (PK) less than that of the AIM-7E and AIM-7F Sparrow variants utilized in Vietnam which had a PK of between 8-10%.[21] A maximum of 24 R-27 missiles were fired throughout the war–which were likely the R-27R variant, but only one R-27 managed to maneuver close enough to its intended target such that its radar proximity fuse to activated. In contrast, the R-73 proved itself as a lethal WVR missile; a total of nine missiles were launched resulting in five aerial victories or a PK of 55%.[22] As Cooper and Kyzer explain, the majority of engagements between EtAF Su-27s and ERAF Mig-29s occurred within visual range. Curiously, the Mig-29 – which is often regarded as having superb maneuverability characteristics – performed poorly against the larger Su-27. It’s possible the disparity in aerial victories between the ERAF and EtAF is attributable more towards training and personnel quality issues rather than hardware. It is unclear to the extent, if at all, the engagements between the ERAF and EtAF influenced Russian defense developments in the late 1990s to early 2000s.

    After the poor performance of the AIM-7 in Vietnam, the U.S. made significant investments in upgrading the AIM-7 between 1970 into the 1980s such as greater jam resistance, look-down shoot-down capability, improved rocket motor, etc.[23] However, it is generally understood that the Russian defense industry received little in terms of research and development funding during the 1990s and early 2000s as a result of Russia’s financial difficulties; many new projects had to be sustained by export orders. Therefore, it is unclear to the extent in which Vympel tried to rectify the R-27’s shortcomings through upgrades or design changes to new missile orders. It is also unclear if the engagements during the Eritrean-Ethiopian War had impact on Russian conceptions of ideal fighter characteristics, e.g. such as emphasis on WVR maneuvering. The combination of continued investments in the R-73 while the development of the R-27’s successor, the R-77, lagged suggests the Russian Air Force weighed WVR capabilities as a higher priority.



    AAM Guidance Notes


    • SARH guidance is the process in which the launch platform illuminates a target with its radar and the missile’s onboard receiver detects the reflected radar energy. By comparing the reflected beam’s characteristics to its source, the missile is able to determine the targets position and speed.[24] In order to properly function, SARH guidance requires the launch platform’s radar to continuously track and illuminate the target–which imposes limitations on the launch platform’s freedom to maneuver–and missile’s receiver must continuously detect the reflected radar energy. Furthermore, SARH requires the launch platform’s radar to continuously emit signals thereby exposing the launch platform to radar warning receivers (RWR) and other emission location systems.[25] However, SARH provides substantial BVR capabilities when compared to IR guided missiles.
    • IR guided missiles do not emit signals, rather they home in on heat sources (infrared radiation) such as jet engines. In order to successfully intercept the target, IR seekers must discriminate against background IR radiation sources and IR countermeasures. The first IR guided missiles could only be fired against tail-aspect targets as a result of seeker limitations. Subsequent generations of IR guided missiles such as the AIM-9L are all-aspect capable. The principal limitation of IR guided missiles is the limited detection range of their seekers. The latest generation of IR guided missiles such as the AIM-9X Block II feature lock-on after launch (LOAL) capability.
    • PRFH missiles similarly do not emit signals, but home in on RF emitting targets.
    • ARH missiles have their own radar seekers which activate during the terminal stage of flight. ARH guided missiles enable “fire and forget” capability i.e. the pilot has freedom to maneuver after initially designated the target with the plane’s radar. By having its own seeker (often a monopulse X-band seeker), ARH missiles are inherently less susceptible to certain forms of jamming.

    Author’s Note
    : I’m still planning on writing that article with 12 Raptors vs 48 Su-35s. There are far more variables than I had anticipated so I’m still researching a couple of topics like Russian air defense doctrines, electronic warfare, “jointness” between the various armed services, battle management networks, datalinks (which are very hard to research) as well as basic fighter maneuvering tactics. As such I’ll probably write an article or two on the topics above for my own edification. Below is a teaser to show some of the assets which will show up in the backstory and simulation:


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    Note that the 790th fighter regiments do not operate the Su-35S at this time. Only the 22nd and 23rdfighter regiments operate the Su-35S in large numbers (the 159th just received there first four aircraft in November 2016), but more deliveries will take place between 2016 and 2020. A typical squadron of fighter aircraft in the VKS consists of at least 12 aircraft.

    Cont...
     
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  3. layman

    layman Aurignacian STAR MEMBER

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    Part - III


    R-77/AA-12 Adder

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    Image 1: R-77-1 mounted on the inner most wing pylon of an Su-35S deployed to Syria. Note the supplemental Khibiny-M EW/ECM pods on the wingtips.

    The most advanced medium-range BVR ARH missile in the VKS inventory is the R-77-1; the missile is also referred to as the RVV-SD and Izdeliye 170-1 in Russian language sources. The R-77-1 is a modernized variant of the original R-77 (Izdeliye 170) AAM developed during the early to mid-1980s. The baseline R-77 was produced by the Molniya OKB in Ukraine in limited quantities solely for testing purposes until 1994. In 1993, the Russian Air Force ordered the R-77 production line and all further developmental activities be transferred to Vympel NPO in Moscow.[1] As a result of financial difficulties during the 1990s, the Russian Air Force did not adopt the R-77 into service. Vympel relied upon sales of the export variant of the R-77, the RVV-AE, to sustain the R-77 production line. As of August 2011, at least 1,500 RVV-AEs have been sold to the PRC and at least 800 RVV-AEs were sold to India; Malaysia, Indonesia, Sudan, Syria, and Peru also have stocks of RVV-AE missiles for use on their MiG-29 and Flanker fleets.[2]

    The Russian Air Force ordered its first batch of improved R-77-1 missiles in 2009 in tandem with its initial Su-35S purchase, deliveries of R-77-1 missiles began in 2011. According to editor-in-chief of the Moscow Defense Brief, Mikhail Barabanov, the VKS ordered two additional batches of R-77-1 missiles in 2012 and 2015 which are expected for delivery between 2016 and 2017; the 2015 contract is worth 13.175 billion rubles ($226 million) which roughly equates to more than 220 missiles. Barabanov further notes that the VKS is unlikely to have “sufficient” stocks of R-77-1 missiles until the latest batches are fully delivered.[3] However, it is unclear if the contracted R-77-1 purchases will prioritized for the Su-35S fleet or will be evenly distributed amongst the VKS’ fighter forces such as the Su-30M2 and Su-30SM regiments.

    In February 2016, operationally deployed R-77-1 missiles were observed for the first time on the Su-35S. However, as of April 2017, the vast majority of Russian fighter aircraft photographed in Syria and those conducting aerial intercepts over Europe continue to be predominately armed with R-27 AAM.

    Design and Performance

    The R-77 is 3.6 meters long, has a diameter of 200 mm, and a launch weight of 175 kg. The baseline variant has a maximum kinematic range of 40.5 nm or 75 km. The missile’s most distinguishing trait is its use of lattice fins which provide excellent subsonic and supersonic maneuverability performance. However, lattice fins tend to generate greater drag than conventional control surfaces at transonic speeds and generate larger radar returns.[4] The R-77’s guidance system comprises of an inertial midcourse system with radio updates as well as an Agat 9B-1348 X-band monopulse active radar terminal seeker which has a home-in-on-jam capability. The slightly modified 9B-1348E in the RVV-AE can detect a 5m^2 target at a range of 16 km or a 0.0002m^2 target, F-22’s frontal RCS, at 1.27 km.[5] Unlike the R-27, the R-77 utilizes a laser proximity fuse to activate the missile’s 22.5 kg blast fragmentation warhead. In principle, a laser proximity fuse equipped AAM should be more effective detecting low observable targets and successfully cueing the warhead when compared to a radar proximity fuse equipped AAM.

    The R-77-1 is an evolution of the original design and features a more streamlined nosecone, software updates, and enlarged fuselage which is 17 centimeters longer and 15 kg heavier than the baseline R-77. In terms of performance, the R-77-1 has an extended kinematic range of 60 nm (110 km) and incorporates the improved 9B-1348-1 seeker which features a more powerful transmitter and receiver over the baseline 9B-1348.[6][7]

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    Image 2: PAK FA captive carry tests with R-77-1 and R-73 missiles. Image Credit: Anatoly Burtsev

    The R-77M (Izdeliye 180) is a “deep modernization” of the original R-77 design which replaces the lattice fins with conventional tail control surfaces for RCS reductions and improved transonic drag performance, incorporates a modernized active terminal seeker produced by Istok (possibly an AESA), and an improved dual-pulse rocket motor which will more than double the range of the original R-77 missile to roughly 81 nm + (150 km+).[8][9] In 2007, the Russian Air Force planned to field the R-77M by 2010, but the absence of operationally deployed R-77M missiles in 2017 suggests either budgetary or technical issues have impaired the R-77M program.[10] Russian defense publications often report the R-77M is the principal BVR weapon of the PAK FA which would suggest an entry date around 2020. However, As of February 2017, all R-77 external captive carry tests with the PAK FA feature the R-77-1 not the R-77M. Therefore, Russia’s fighter forces will likely continue to rely upon the R-77-1 until at least the mid-2020s as its primary AAM. Similarly, the ramjet powered R-77ME has been proposed since at least 1999 when a mockup was presented at that year’s Farnborough airshow, but little credible evidence within the public domain suggests that the R-77MD’s development has progressed.

    Su-35S Electronic Warfare & Self Protection Systems

    The Su-35S features a robust ECM suite designed to defeat and delay detection across the electromagnetic spectrum including the CKBA L150-35 Pastel RWR, KNIRTI L265M10R Khibiny-M ECM suite, NPK SSP ultraviolet missile approach warning system (MAWS), and six 14-round UV-50 decoy dispensers.[11] These systems complement one another to significantly enhance the Su-35S’ survivability against radar and IR guided AAMs.

    Beyond Visual Range

    The internally stored components of the Khibiny-M system cover the H-J (X to Ku) bands while the optional wingtip mounted pods cover the E-G bands (S to X). The Khibiny-M is likely linked to the L150-35 RWR to enable several common ECM and EW techniques such as noise jamming, repeater jamming, and deceptive electronic counter measures (DECM).[12] The basis for all ECM systems is for the jamming signal to exceed the skin return of the aircraft from the perspective of the adversary radar.[13] For example, when an adversary radar is within range of a repeater ECM equipped aircraft, the ECM suite detects the radar pulse against the skin of the aircraft (skin return), amplifies the skin return, and repeats the false signal at random intervals back toward the adversary radar. This technique effectively masks the location of the aircraft by generating false targets on the adversary’s radar.[14]

    Surviving until the merge will be critical for Su-35S pilots engaging fifth generation aircraft because their adversary’s use of stealth will both severely diminish BVR opportunities and degrade radar guided AAM PK performance in terms of terminal seeker sensitivity and radar fuse failures. Under ideal conditions for VKS pilots, Su-35S’ would be directed toward stealthy aircraft via external long-range sensors such as VHF radars or extremely sensitive emissions detection systems. Compared to fifth generation aircraft, the Su-35S is more reliant on its ECM/EW suite to protect the aircraft until the merge at WVR given its much larger RCS. All of these techniques require knowledge of the adversary radar’s location identified by the RWR. However, U.S. AESA equipped aircraft operating in low probability of intercept (LPI) mode will prove significantly more difficult for the Su-35S to detect, track, and jam.

    A major determinant of the Su-35S’ effectiveness against Western militaries will be the ability of the Khibiny-M to degrade the probability of kill (PK) of the AIM-120D AAM. The AIM-120D features an X-band monopulse terminal seeker with a diameter of approximately 178 mm and a home-in-on-jam capability against noise jamming emitters.[15] Furthermore, monopulse radars are inherently immune to signal amplitude modulation jamming because they generate an error signal based upon each pulse.[16] Arguably, the greatest deficiency of the AIM-120D is its limited sustained kinetic performance compared to emerging ramjet powered AAMs such as the MBDA Meteor. The AIM-120 has a historical PK of 0.46 against Iraqi and Serbian Air Force aircraft, but both EW and missile guidance technology have significantly progressed since the 1990s such that the historical PK is likely no longer informative of the current PK. Because both the AIM-120D and Khibiny-M’s most sensitive specifications are not likely to be released, I believe there is significant uncertainty regarding the ability of the Su-35S to close to WVR of fifth generation aircraft without sustaining substantial casualties.

    Within Visual Range

    The Su-35S’ MAWS can detect the launch of a man-portable air-defense system (MANPADS) from 10 km away (6.2 miles) as well as SAM and AAM launches at 30 km (19 miles).[17] Very little information on the Su-35S’ MAWS exists among English language sources, but the system should in principle give VKS pilots greater reaction against missile threats. MAWS are particularly useful in defending against IR and other types of passive guided AAMs which will avoid detection on the aircraft’s RWR.

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