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Monday, November 14, 2016

Threat Analysis: Su-35S Part II - Armament R-27 & R-73

Threat Analysis: Su-35S Part I



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




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
  

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 to complete 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.


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]

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.  

Author’s Note: Part III will discuss the R-77 family of BVR ARH missiles as well as probable TTP of Su-35 pilots.

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:



Note that the 790th fighter regiments do not operate the Su-35S at this time. Only the 22nd and 23rd fighter 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.

Works Consulted

George M. Siouris, Missile Guidance and Control Systems, Springer-Verlag New York, 2004. 

Jeffrey T Richelson, The U.S. Intelligence Community, Westview Press, Jul 14, 2015.

Piotr Butowski, “Russian Air Power Almanac 2015”, Air Force Magazine, 2015. http://www.airforcemag.com/MagazineArchive/Magazine%20Documents/2015/July%202015/0715russia.pdf

Sebastien Roblin, "Russia's MiG-29 Fulcrum: A Super Fighter or Super Failure?", July 2016. http://nationalinterest.org/feature/russias-mig-29-fulcrum-super-fighter-or-super-failure-17054 

Tactical Missile Corporation, “Products”, last accessed November 2016. http://eng.ktrv.ru/production_eng/




[1] Artem Company, “R-27 missiles”, last accessed November 2016.
[2] Vympel offers R-27EP anti-radar air-to-air missile Piotr Butowski
[3] Artem Company, “R-27 missiles”, last accessed November 2016.
[4] Piotr Butowski, “The Flanker Family Part Two: Upgrades, Su-33 and Su-35”, Combat Aircraft September 2016 Issue, pgs. 61-66.
[5] Sukhoi Products: Su-35 multi-role fighter, last access October 2016. http://www.sukhoi.org/eng/planes/military/Su-35/
[6] Piotr Butowski, “The Flanker Family Part Two: Upgrades, Su-33 and Su-35”, Combat Aircraft September 2016 Issue, pgs. 61-66.
[7] Global Security, “AA-10 ALAMO R-27”, last updated November 2011. http://www.globalsecurity.org/military/world/russia/aa-10-specs.htm
[8] Jane’s, “Russian Air-Launched Weapons 38”, 2001.
[10] Piotr Butowski, “Vympel offers R-27EP anti-radar air-to-air missile”, 2007.
[12] Tyler Rogoway, “How To Win In A Dogfight: Stories From A Pilot Who Flew F-16s And MiGs”, 2015. http://foxtrotalpha.jalopnik.com/how-to-win-in-a-dogfight-stories-from-a-pilot-who-flew-1682723379
[13] Piotr Butowski, Jane's International Defense Review, August 2014.
[14] BMPD/ CAST, “Helmet-mounted target designation system NSTS-T for Russian fighter jets”, November 2016. http://bmpd.livejournal.com/2200980.html
[15] Piotr Butowski, Jane's International Defense Review, August 2014.
[16] Pieter D. Wezeman “United Nations Arms Embargoes Their Impact on Arms Flows and Target Behavior Case study: Eritrea and Ethiopia, 2000–2001.” http://books.sipri.org/files/misc/UNAE/SIPRI07UNAEE-E.pdf
[17] Ibid.
[18] Jonathan Kyzer, et al., Air Combat Information Group, “Air War between Ethiopia and Eritrea, 1998-2000”, 2003.  http://www.acig.info/CMS/?option=com_content&task=view&id=138&Itemid=47
[19] Ibid.  
[20] Ibid.
[21] Ibid.
[23] F-16.net, “AIM-7 Sparrow”, last accessed November 2016. http://www.f-16.net/f-16_armament_article10.html
[24] Robert L. Shaw, Fight Combat Tactics and Maneuvering, pp. 38
[25] Robert L. Shaw, Fight Combat Tactics and Maneuvering, pp. 38 

Tuesday, October 25, 2016

Threat Analysis: Su-35S


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.[i] 


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 equipment and (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



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.


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.


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.

Threat Analysis: Su-35 Part II - Armament R-27 & R-73


Author’s Note: Part II will cover the Su-35’s electronic warfare and countermeasures suite, engines, armament, and potential TTP Russian pilots will use to best maximize the comparative strengths of the Su-35.

 Works Cited 

My sincerest apologies on the formatting, the blogger template is terrible for formatting citations. 


[1] Suhkoi Products: Su-35 multi-role fighter, last access October 2016. http://www.sukhoi.org/eng/planes/military/Su-35/
[2] Matt, “The Benefits of Stealth and Situational Awareness”, November 2013. https://manglermuldoon.blogspot.com/2013/11/the-benefits-of-stealth-and-situational.html.
[3] General Hawk Carlisle, “5th Generation Fighters”, February 2012. http://secure.afa.org/events/Breakfasts/Breakfast_2-28-12_LtGen_Carlisle.pdf
[4] Piotr Butowski, “The Flanker Family Part Two: Upgrades, Su-33 and Su-35”, Combat Aircraft September 2016 Issue, pgs. 61-66.
[5] Defense Industry Daily, “Russia’s Su-35 Super-Flanker: Mystery Fighter No More”, last updated October 2016. http://www.defenseindustrydaily.com/russias-su-35-super-flanker-mystery-fighter-no-more-04969/
[6] Nikolai Novichkov, “Russia orders 50 Su-35S multirole fighters”, January 2016. http://www.janes.com/article/57187/russia-orders-50-su-35s-multirole-fighters
[7] Vladimir Karnozov, “Russia May Slow T-50 Production for Economic Reasons”, March 2015. http://www.ainonline.com/aviation-news/defense/2015-03-31/russia-may-slow-t-50-production-economic-reasons 
[8] Ibid.
[9] Julian Cooper, “Russia’s state armament programme to 2020: a quantitative assessment of implementation 2011–2015”, March 2016.   
[10] Craig Caffrey, “Russian Defense Budget Set to Drop 12%”, October 2016. http://www.janes.com/article/64911/russian-defence-budget-set-to-drop-by-12
[11] Piotr Butowski, “The Flanker Family Part One: The Multi-role Su-30”, Combat Aircraft October 2016 Issue, pp. 67.
[12]Global Security, “Su-35BM (Bolshaya Modernizatsiya - Big Modernization)”, last updated July 2011. http://www.globalsecurity.org/military/world/russia/su-35bm-design.htm
[13]Carlo Kopp, “Sukhoi/KnAAPO Su-35BM/Su-35-1/Su-35S Flanker”, last updated 2012. http://www.ausairpower.net/APA-Su-35S-Flanker.html
[14] AWIN Program Profiles, Sukhoi Su-27/30/32/34/35, Aviation Week, last accessed October 2016.
[15] Dan Katz, “Raptor Revisited”, Aviation Week Space and Technology July 4-17, pgs, 75-76.  
[16] Sukhoi, Su-35: Multifunctional Supermaneuverable Fighter, last accessed October 2016. http://www.knaapo.ru/media/eng/about/production/military/su-35/su-35_buklet_eng.pdf
[17] Russia’s Warplanes: Volume I, pgs. 87-91, Houston: Harpia Publishing L.L.C. & Moran Publishing, 2015,
[18] Ibid.
[19] Ibid.
[20] Ibid.
[22] Piotr Butowski, “The Flanker Family Part Two: Upgrades, Su-33 and Su-35”, Combat Aircraft September 2016 Issue, pgs. 61-66.
[23]Reuben F Johnson, “Singapore Airshow 2016: Analysis - PAK-FA's Asian export hopes stymied by lack of 'fifth-generation' qualities”, February 2016. http://www.janes.com/article/58166/singapore-airshow-2016-analysis-pak-fa-s-asian-export-hopes-stymied-by-lack-of-fifth-generation-qualities

Works Consulted

J. Thomas Anderson, "How Supersonic Inlets Work: Details of the Geometry and Operation of the SR-71 Mixed Compression Inlet", August 2013. 

Advisory Group For Research and Development - North Atlantic Treaty Organization, "Precision Terminal Guidance for Munitions", 1997.

Tyler Rogoway, "Infrared Search And Track Systems And The Future Of The US Fighter Force", March 2015. 




Endnotes

[i] For example, Sukhoi considered incorporating S-shaped inlets in PAK FA to reduce its frontal radar cross section (RCS), but ultimately decided the weight and length penalties associated with S-shaped inlets were too great. The current inlet design is a compromise which includes radial blockers and RAM as well as a variable throat section, spill doors on the inboard, outboard, and lower surfaces of the ducts. The combined effect of these features optimizes airflow at supersonic speeds while reducing the frontal RCS. However, even with radial blockers and RAM treatments, inlets are responsible for roughly 60% of the PAK FA’s frontal RCS; the patent document states the design goal was a frontal RCS between 1.0-0.1m^2 which is, at its smallest, roughly 77 times larger than the F-35 or 500 times larger than the F-22A [Source: Aviation Week Intelligence Network (AWIN) Program Profiles, T-50, last accessed October 2016].

[ii] As Piotr Butowski explains, the Su-30 family is broadly divided between those manufactured by the Irkutsk and Komsomolsk-on-Amur plants in Russia’s Warplanes: Volume I. The Irkutsk line consists of the Su-30MKI, Su-30MKM, and Su-30SM which are generally more capable than the Su-30MKK, Su-30MK2, Su-30MK2V, and Su-30M2 produced by the Komsomolsk-on-Amur plant. Visually, each line of Su-30s can be distinguished as the Irkutsk line includes canards and the Komsomolsk-on-Amur does not.

[iii] Several short range surface to air missile systems such as the U.S. Army’s Avenger system utilize a laser rangefinder to provide data for the fire control system. Airborne systems such as the ATFLIR pod produced by Raytheon for the F/A-18E are only discussed as providing laser designation against ground targets. 

Thursday, October 20, 2016

Article Announcement: F-22A vs Su-35


Image 1: Su-35S. Image Credit: Mikhail Voskresenskiy 

By next week I  will publish an article detailing a hypothetical engagement between a dozen F-22As and 48 Su-35s around 2020. The purpose of the article is to identify the challenges future Raptor pilots are going to face and how those challenges should inform potential mid-life upgrades of the F-22. Going forward, I will try to include additional analysis on Russian systems on this blog. I will be sure to list all of my assumptions and methodology in the endnotes as trying to predict an accurate engagement with only open source data is extremely difficult.

Recommended Media


Sunday, September 25, 2016

Building the F-22C "Super Raptor": Improvements Part - III



Image 1: Notional F-22C upgrade package. 



While the enhancements described in Part II will rectify some the inherent design deficiencies of the base F-22A - such as range and limited computing power, additional changes are needed to ensure the F-22 can operate in the most contested environments in the post-2030 timeframe. The key elements of any F-22C upgrade program would include additional sensors to improve situational awareness, survivability, and munitions integration and storage capacity. Overall, the majority of these upgrades will assist in within visual range engagements and survivability against infrared (IR) guided missiles. Each upgrade recommendation varies in technical complexity, schedule, and cost which invariably will make certain upgrades more attractive to the USAF than others. 

Sensors
Sidelooking AESAs


Image 2: Proposed F-22 growth options by Karlo Copp. Image Credit: Air Power Australia & Carlo Kopp, 2006.  

      The existing F-22 sensor suite is arguably the most capable of any fighter aircraft with the exception to the F-35. The APG-77 active electronically scanned array (AESA) radar consists of at least 2,000 transmit receive modules which can detect a 1m^2 rcs target at a distance of 150 nautical miles (nm) all the while changing its frequency 1,000 times per second under its low probability of intercept (LPI) mode to evade emission locator systems.[1] The passive detection capabilities of the F-22 are arguably even more impressive, BAE’s ALR-94 radar warning receiver (RWR) and digital electronic warfare suite enables the F-22 to perform precise geolocation and tracking of emitters from any direction up to 250 nm away; the details of this capability are highly classified but it is plausible the fidelity of the geolocation capabilities are of a high enough quality to provide target quality tracks for weapons employment i.e. narrowband interleaved search and track (NBLST) mode.[2] However, the key to leveraging all of the F-22’s powerful sensors – and arguably the area of greatest difficulty to developing a fifth generation fighter, is the F-22’s software which fuses sensor inputs and disseminates critical information for the pilot thereby providing unmatched situational awareness of his or her environment. Despite the already impressive capabilities of the baseline F-22A, changes to the threat environment and USAF procurements since termination of the production line necessitate additional upgrades to the F-22’s sensor suite.
      With its current suite of sensors and enhanced situational awareness, Raptor pilots over the skies of Syria haven taken on battle management duties; the superior understanding of the battlespace by Raptor pilots provides nascent airborne warning and control (AWACS) capabilities to Coalition forces.[3] The Raptor’s command and control (C2) role will only grow in importance should the U.S. fight in a highly contested environment where the safety of E-3 and E-2D AWACS aircraft – even at stand-off ranges, is not assured. Furthermore, the limited production run of F-22 and the vast geographic expanse of likely conflict zones both the Asia-Pacific and Europe will force a standard four ship formation of F-22’s to undertake much more demanding combat air patrols for both offensive and defensive counter air missions. A potential solution to expand both the F-22’s C2 capabilities and enable small units of F-22s to cover wider areas of responsibility would be the installation of sidelooking AESA radars which would provide much greater horizontal and vertical coverage. Furthermore, these arrays could utilize a lower frequency band, such as the L-band sidelooking arrays utilized on the Su-35, to improve detection capabilities against low radar cross section targets optimized for the X and S-band.[4]


Image 3: 2008 PO document courtesy BDF and F-16.net. Note: this document is out of date, but it does provide valuable insight towards a much longer term upgrade roadmap than the current Increment series. The desire for additional C2 and ISR capabilities is particularly noteworthy. 

The F-22A’s existing superstructure has provisions for sidelooking phased array radars as a growth option for further development.[5] The upgrade would not be necessary for every F-22, even upgrading only the flight lead’s and element lead’s aircraft within a four aircraft formation would enable much greater operational flexibility. For example, during the Persian Gulf war, it was standard practice for two pairs of F-15Cs to fly in the beyond visual range fighting formation known as the “Wall of Eagles”:
Using their radars, all formation members searched the area ahead of them usually in a 120 degree azimuth sweep, which covered an 80 nm wide arc at 40 miles off the nose. With as much as five miles between the wingmen, at 40 nm the entire formation searched an 85-mile-wide swath, making it difficult for an adversary to outflank the formation, or escape detection…Each two-ship element in the ‘Wall of Eagles’ formation searched with their radars from the earth’s surface to the base of the contrail level, the two elements ensuring overlapping coverage. Additionally, the wingman visually scanned the contrail layer for telltale signs of aircraft approach in that altitude band. – F-15C Eagle vs Mig-23/25, Douglas C. Dildy and Tom Cooper, pp. 43, 2016. 
This formation maximized the probability of detecting adversary aircraft across the assigned mission area of combat air patrols. The potential coverage of two pairs of F-22s employing a similar tactic would dwarf the original, but the effectiveness of the tactic would be augmented considerably if at least two aircraft per formation were equipped with sidelooking arrays providing vertical and substantial additional horizontal coverage.
            In the low observable “AWACS” role, side panel equipped Raptors could provide a highly survivable situational awareness capability for the joint force even within contested airspace. As of fiscal year 2017 USAF budget documents, 72 F-22As will receive Link 16 capabilities in an unspecified waveform and all F-22s will receive IFTL Gateway mode which will enable 5th to 4th generation communications. Even after expending all internal weapons, F-22s will likely remain close to the battlefield provided fuel is not a constraint given their unique highly survivable battle management and command and control capabilities: 
After their missiles were fired, the F-22’s active & passive sensor capabilities functioned as the Raptor’s last weapon. Northern Edge 2006’s Raptors remained in the fight, flying as stealthy forward air controllers and guiding their colleagues to enemies sitting behind mountains and other ‘Blue Force’ AWACS blind spots. When the AIM-120D AMRAAM missile enters wider service, F-22s will also have the option of actively guiding missiles fired by other aircraft.[6]
Overall assessment (1 – low, 5 – High):
            Relative Utility: 3/5 – Intermediate
            Technical Feasibility and Cost: 3/5 – Intermediate

Recommendation: Further technical and cost analysis required utilizing classified information is likely required to make a full assessment. The U.S. has yet to field a fighters equipped with sidelooking arrays as of 2016. All existing USAF aircraft employing sidelooking arrays are optimized at observation of ground targets such as JSTARS and Global Hawk.[7] Any contract would likely be a sole source to Northrop Grumman since the system would have to be integrated with the existing APG-77(V)1. Air Power Australia is among the few sources in the public domain which states the base airframe has provisions for sidelooking arrays, internal modifications since the initial design may have utilized any existing growth margin. Furthermore, the full capabilities of the APG-77(V)1 may be sufficient to provide acceptable C2 capabilities without further investments. Determining the extent to which additional capabilities are needed to monitor contested airspace likely merits its own in-depth technical study.

Incorporating a different frequency band in the sidelooking arrays has the potential to provide greater flexibility against intensive adversary jamming against the X-band. However, the APG-77(V)1 is already highly resistant to jamming. Furthermore, L-band arrays may not be able to provide similar target quality track information required for weapons employment.

Helmet Mounted Display and Cueing System


Image 4: Third generation HMD for the F-35. Image Credit: Rockwell Collins. 

      Arguably the most glaring current deficiency of the F-22A is its lack of a helmet mounted display and cueing system (HMDCS). HMDs are vital for within visual range engagements as they enable the cueing of advanced off-boresight missiles such as the AIM-9X Block I; off-boresight missiles paired with an HMD enable the pilot to look at an adversary aircraft and gain IR missile lock on the target up to 90 degrees from the launch point. Interception of the target even at extreme angles is possible for modern IR guided missiles as a result of thrust vectoring and freedom from biological g-limit constraints which dictate the maneuverability envelope pilots can sustain. Without an HMD, Raptor pilots have had to rely upon their traditional heads up display (HUD) for IR missile cueing and display of weapons engagement zones (WEZ) which constraints IR targeting to the forward sector. At the operational level, the lack of an HMD can be mitigated somewhat with the lock-on-after-launch (LOAL) feature in the AIM-9X Block II as the missile will loiter in close proximity to the launch point before being re-tasked by the pilot to perform any aspect interception. However, the LOAL feature requires integration of a two-way datalink which will not be completed until the Increment 3.2b upgrades are completed.

Image 5: Off-boresight capability of the Python 4 IR guided missile. Image courtesy of Defense Industry Daily. 

The USAF has tested the Thales Scorpion HMDCS for integration with the F-22 in 2014, but the effort was canceled as a result of sequestration.[8] FY 2017 USAF budget documents indicate the USAF still plans to field a HMDCS system for the F-22 in the near future:
The HMDCS program will select, integrate, test and field a mature HMDCS to take full advantage of advanced weapons such as the AIM-9X, and improved battlespace situational awareness during day/night within-visual-range engagements. The HMDCS will be integrated on all Block 30/35 Raptors.[9]
While the integration of either the Joint Helmet Mounted Cueing System (JHMCS) or the Scorpion HMDCS on the F-22 is likely, there are no official plans to develop and integrate an equivalent to the Rockwell Collins third generation HMD for the F-22. The main advantage of the F-35’s HMD over JHMCS or the Scorpion is its integration with the distributed aperture system – a series of cameras embedded in the F-35’s skin which provides real-time all-aspect tracking of aircraft within a 15 nautical mile radius.[10] However, the F-22 does not require an equivalent of the third generation HMD as it has no equivalent of DAS. Furthermore, the single piece bubble canopy of the F-22 already affords the pilot with excellent visibility when compared to the F-35’s cockpit without DAS. An equivalent to the third generation HMD might be merited depending upon a decision to fuse the sensor inputs of the AAR-56 Missile Launch Detector (MLD) cameras into a cohesive system like DAS as well as the integration of the advanced electro-optical targeting system (EOTS) which will be discussed in the next article.




[1] Dan Katz, “Comparing F-22, F-35 Cost and Capability”, 2016. http://www.w54.biz/showthread.php?3375-Comparing-F-22-F-35-Cost-And-Capability
[2] Bill Sweetman, “The Next Generation, 2000. http://www.f-16.net/forum/viewtopic.php?t=9268
[3] Lolita C. Baldor, “F-22 Raptor Ensures other War-Fighting Aircraft Survive Over Syria”, 2015. http://www.military.com/daily-news/2015/07/21/f22-raptor-ensures-other-war-fighting-aircraft-survive-syria.html
[4] Carlo Kopp, “Assessing the Tikhomirov NIIP L-Band Active Electronically Steered Array”, 2009. http://www.ausairpower.net/APA-2009-06.html
[5] Carlo Kopp, “Lockheed-Martin / Boeing F-22 Raptor”, 2012.  http://www.ausairpower.net/APA-Raptor.html
[6] “Defense Industry Daily, “F-22 Raptor: Capabilities and Controversies”, last accessed September 2016. http://www.defenseindustrydaily.com/f-22-raptor-capabilities-and-controversies-019069/
[7] Defense Science Board, “Report of the Defense Science Board Task Force on Future DoD Airborne High-Frequency Radar Needs/Resources”, 2001. https://www.ciaonet.org/attachments/12186/uploads
[8] Dave Majumdar, “Air Force Evaluating New Targeting Monocle for F-22 Raptor”, 2014. https://news.usni.org/2014/05/16/air-force-evaluating-new-targeting-monocle-f-22-raptor
[9] USAF Budget Documents FY 2017, RTD&E Volume III Part I http://www.saffm.hq.af.mil/Portals/84/documents/FY17/AFD-160208-052.pdf?ver=2016-08-24-102137-043 pp. 420
[10] Dan Katz, “Comparing F-22, F-35 Cost and Capability”, 2016. http://www.w54.biz/showthread.php?3375-Comparing-F-22-F-35-Cost-And-Capability