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, “5^th 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.

[21] Russia Air Force Handbook: Stragegic Information and Weapon Systems, pp. 169, Washington D.C.: International Business Publications, 2011.  https://books.google.com/books?id=Kt2ZaOilGXIC&pg=PA169&lpg=PA169&dq=%22laser+rangefinder%22+r-27&source=bl&ots=vQIYdKWDIW&sig=qjpM4J6ymWARSDFERCXM1ZDqQ_Y&hl=en&sa=X&ved=0ahUKEwiQsoO5gPTPAhXJOj4KHbMFALA4ChDoAQg7MAg#v=onepage&q=%22laser%20rangefinder%22%20r-27&f=false

[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. 

http://www.enginehistory.org/Convention/2013/HowInletsWork8-19-13.pdf

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. 

http://foxtrotalpha.jalopnik.com/infrared-search-and-track-systems-and-the-future-of-the-1691441747 

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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. 

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

US considers Extended Range THAAD, enhanced BMS to defend against attacking hypersonic gliders - by Tamir Eshel

China’s J-20 Stealth Fighter Will Likely Look Like This At Its Air Show Debut - by Tyler Rogoway

Japan Aerospace: Boeing promotes F-15 as air-to-air missile truck - by Greg Waldron 

Russia Plans to Deploy Anti-Satellite Airborne Laser Weapon - Tamir Eshel

Russia Is Moving Ahead With Missile Program That Violates Treaty, U.S. Officials Say - by Michael R. Gordon

New Army Long-Range Missile Might Kill Ships, Too: LRPF - by Sydney J. Freedberg, Jr.

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

Image 1: Notional F-22C upgrade package. 

Part I: Introduction 

Part II: Upgrades: propulsion, range, computing power, and ease of maintenance 

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 5^th to 4^th 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.

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[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

Blog Update September 2016

Apologies for the long publishing hiatus, I have been preoccupied with both work and graduate school. I am currently working on the "Building the F-22 Super Raptor" series; the next two parts will discuss means to improve the Raptor's sensors, countermeasures, and munitions.

Recommended Defense & National Security Media 

Operational Assessment of the F-35A Argues for Full Program Procurement and Concurrent Development Process - John Venable
F-35 Thermal Scan Highlights New Stealth Features - Tamir Eshel
Is the European Meteor Air-To-Air Missile Really the Best in the World? - Tyler Rogoway
Navy Sidelines First 4 LCS; Overhauls Deployment, Crewing- Sydney J. Freedberg, Jr.
China and Ukraine agree to restart An-225 production - Gareth Jennings

A Few Words About TPP

Note: While I intentionally try to avoid politics, the ongoing legislative battle over TPP is of paramount importance and its not getting both the attention intellectual scrutiny it deserves. The TPP is often written-off as corporate power grab in the U.S. media and is now opposed by both presidential candidates. Overall, both political parties have demonstrated a limited understanding of international trade policy and economics this campaign season - particularly regarding TPP and the much lambasted "trade deficit".

"According to the World Bank, in just 10 years, four of the five largest economies in the world will be in the Asia-Pacific region. The United States will be able to shape the 21st century only if it remains a vital Pacific power...The Trans-Pacific Partnership is the sine qua non of Washington’s pivot to Asia because it works at many levels simultaneously — economic, political and strategic. It boosts growth, shores up U.S. alliances, sends a powerful signal to China and, most importantly, writes the rules of the 21st century in ways that are fundamentally American...With the Asia pivot, Obama is pursuing the deepest, most enduring interests of the United States. But in doing so, he is now alone in a Washington that is increasingly awash in populism, protectionism and isolationism." - Fareed Zakaria

• Many Asian countries set aside their parochial economic-industrial interests in order to negotiate with the U.S., particularly Japan under Abe has borne huge political costs. 
• The U.S.' has been able to exact comparatively favorable terms in many aspects of the negotiations given its part of the largest single market in the world (NAFTA). 
• Economics is the study of trade-offs, the net benefit to the services sector as well as the agricultural, technological, and pharmaceutical industries offsets losses in manufacturing. By many counts TPP will only produce modest growth to the U.S. economy, its real purpose lies within international politics e.g. U.S. trade volume with Vietnam is projected to surge. 
• Securing robust trade relationships with developing Asian countries lays the groundwork for maintaining the U.S.' long-term soft power influence in the region to offset China.
• Should the U.S. fail to pass TPP, the U.S. reputation in the Asia-Pacific will be damaged for years to come:
• "The Japanese living in an uncertain world depending upon the American nuclear umbrella will have to say, on trade the Americans could follow through, if its life and death, whom do I have to depend upon?...Its an absolutely serious calculation which will not be said openly, but I have no doubts it will be thought" - PM Lee Hsien Loong
• Senate Majority leader Mitch McConnell has stated he does not intended to bring TPP to the floor of the Senate for a vote even after the November 2016 elections. 

If nothing else, the TPP deserves serious discussion and examination this campaign season. It is one of the few proactive efforts, rather than crisis control, aspects of U.S. foreign policy which has the potential to secure U.S. influence in the most dynamic and populous region of the world decades to come. 

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

PART I

While the F-22 is unambiguously the most lethal air-to-air platform in existence, the F-22 was designed during the 1980s and 1990s under a different threat and technological environment. Namely the F-22’s antiquated internal computing capabilities, software, limited combat radius, and high maintenance requirements degrade the utility of the F-22 within the context of operating in the Asia-Pacific against increasingly capable great power threats. Part II will examine these deficiencies further in preparation for an analysis of what features an F-22C could include which would both correct these shortcomings and add new capabilities to the F-22 airframe in Part III.

1980s Hardware & Software

Image 1: F-15C cockpit vs. F-22A. F-15C image courtesy of Eagle.RU forums. 

            The avionics suite of the F-22 is among the most capable of any fighter in service in terms of raw performance, the AN/APG-77 active electronically scanned array (AESA) and ALR-94 radar warning receiver (RWR) provide unmatched active and passive detection capabilities. Data collected from the F-22’s avionics suite are fused and presented on six liquid crystal displays in the cockpit providing unmatched situational awareness when compared to primarily analogue switches and cathode ray tube based displays within 4^th generation cockpits. However, the original internal computing hardware and software that manages the F-22’s avionics are obsolete.

Image 2: F-22 internal computing systems. Image Credit: F-22 avionics handbook, Ronald Brower, 2001. 

            Two Hughes Electronics designed common integrated processors (CIP) provide the computing backbone of the F-22 avionics and flight systems which enable dissemination of radar, communication, electronic warfare, and systems data.[1] The CIP is a modular design composed of 66 Standard Electronic Module Size – E (SEM-E) units each which are in turn connected to Dual Data Processing Elements (DDPE) on each side of the SEM-E units; the DDPEs feature two 32-bit, 25-MHz, Intel 80960 (i960) processors which collectively provide the bulk of the F-22’s processing capability to support its integrated avionics suite.[2] Polyalphaolefin liquid coolant provides thermal management for both the CIP racks and AN/APG-77 radar. Each CIP is capable of computing 10.5 billion calculations per second and have a maximum memory capacity of just 300 megabytes each. The software which runs the F-22’s hardware is equally dated.

Image 3: F-22 CIP. Image Credit: Hughes Aircraft Co, 1996.  

Of the 1.7 million lines of code responsible for running the F-22s various systems, 90% is written in Ada - a prehistoric programming language developed in 1980. In a Wall Street Journal editorial against the F-22 program, former Secretary of the Navy John Lehman sarcastically remarked, “At least they [the F-22] are safe from cyberattack since no one in China knows how to program the '83 vintage IBM software that runs them”.[3] Despite the limitations of the F-22’s current hardware and software, Lockheed Martin engineers ensured the aircraft had significant growth margins to accommodate future computing advances.

            A total of 19 SEM-E slots in CIP 1 and 22 SEM-E slots in CIP 2 are vacant to facilitate future growth.[4] Furthermore, provisions were made within the F-22 airframe to facilitate future incorporation of a third CIP.[5] Production of the i960MX ceased in 1997 and it’s likely that the CIP’s original hardware was upgraded, but these upgrades are not well documented. Under the common configuration program (CCP), Defense Industry Daily reports, “F-22A Block 10s were retrofitted to Block 20/ Increment 2 status, but retain the original core processor [implying a new processor has been fielded]”.[6] In 2001, Military and Aerospace Electronics, reported that PowerPC processors would be integrated into lot 5 production aircraft:

…an upgrade to a new PowerPC processor already is on the drawing board, beginning with Lot 5 production of the aircraft around 2004…When the time comes, designers say they expect to replace the signal processor with a PowerPC using AltiVec technology, Motorola's high-performance vector parallel processing expansion to the PowerPC RISC processor architecture. AltiVec adds a 128-bit vector execution unit operating in concert with the PowerPC's existing integer and floating point units to provide highly parallel operations, as many as 16 simultaneously in one clock cycle.

The full extent of the CIP’s upgrades are not apparent from public sources, but it’s likely the original obsolescent parts were at least partially replaced for sustainment purposes since Lot 5. Given the additional sensors and networking capabilities envisioned in an F-22C, which will be detailed in Part III, it’s likely the current baseline computing hardware will require additional upgrades. Furthermore, the USAF ought to examine the feasibility and relative utility of upgrading to a C++ or non-Ada based operating system while also keeping cybersecurity in mind. The Integrated Maintenance Information System (IMIS), the rough equivalent of AILIS for the F-22, is currently being upgraded to the C++ standard.[7] The Air Force’s budget materials for FY 2017 under “F-22 Small Projects” lists “Windows XP migration” as a planned upgrade.[8]

[UPDATE 9/25/16]: Forecast International reports a third CIP was added on lot 5 production aircraft and beyond. 

Range

Image 4: F-22A range comparison, the chart is somewhat biased against the F-15E given the HLLH configuration. Image Credit: Lockheed Martin. 

Arguably the most substantial limitation of the F-22 is its limited range. On internal stores only, the F-22 has a subsonic combat radius of 590 nautical miles (nm). With the addition of a pair of 500 gallon drop tanks, which are mounted from detachable pylons on the wing to enable reestablishment of the F-22’s stealth outline, is 850 nm. However, even a range of 850 nm is fairly limited when compared to the vast geographic expanse of the Asia-Pacific. The original advanced tactical fighter requirements were tailored to the strategic situation of the Cold War in which the U.S. air campaign would be fought from a network of bases in the U.K. and Western Europe which were comparatively close proximity to Warsaw Pact forces.

            In order to both improve the relevance of the Raptor to the Asia-Pacific and reduce the strain on aerial refueling assets during a high-end conflict, the F-22C would add both variable cycle engines and conformal fuel tanks. Variable cycle engines are likely to be among the defining traits of six generation aircraft, provided such a platform centric approach is pursued, and provide numerous performance benefits when compared to current turbofan engines:

To alter bypass ratio, variable-cycle engines add a third airflow stream outside of both the standard bypass duct and core. The third stream provides an extra source of airflow that, depending on the phase of the mission, can be adapted to provide either additional mass flow for increased propulsive efficiency and lower fuel burn, or to provide additional core flow for higher thrust and cooling air for the hot section of the engine, as well as to cool fuel, which provides a heat sink for aircraft systems. During cruise, the third stream can also swallow excess air damming up around the inlet, improving flow holding and reducing spillage drag.[9]

Variable cycle engines have the potential to provide between 25% and 35% greater range and 10% greater thrust when compared to traditional turbofan engines.[10] Furthermore, the third stream of air provides additional heat sink capacity which would facilitate both the incorporation of additional avionics – which often generate excessive heat, and directed energy weapons.[11]

Image 5: F-22A drop tank test. Image Credit: Lockheed Martin. 

            The addition of conformal fuel tanks would greatly expand the Raptor’s range at minimal cost to maneuverability, for example, the F-15’s Fuel And Sensor Tactical (FAST) CFTs provide an additional 1,698 gallons of fuel while the F-16C Block 52’s CFTs provide 900 additional gallons, and the Advanced Super Hornet’s CTFs provide 3,000 pounds of additional fuel combined. The addition of variable cycle engines and CTFs could expand the F-22B’s combat radius to approximately 825 nm or greater than 1,180 nm with two drop tanks.[i] However, the addition of CTFs would degrade the F-22’s stealth performance by virtue of disrupting the careful balance of planform alignment, the process in which multiple flight surfaces of an airframe share the same angle such that they reflect radar waves way from the source; shaping techniques provide between 80-90% of radar cross section (RCS) reductions while radar absorbent material (RAM) coatings provide the remainder.

            The relative utility of mounting CFTs for the F-22 would depend upon the extent of RCS degradation and the expected threat environment. For example, even if the CTFs would entirely negate the F-22’s stealth characteristics, CTS would still be useful for ferry flights between distant Pacific bases such as Joint Base Pearl-Hickam in Hawaii and Kadena Air Base in Japan. However, it is unlikely the addition of CTFs would entirely negate the F-22’s stealth when shaped appropriately and treated with RAM. Israeli Aerospace Industries has explored adding CTFs to the F-35.[12] Similarly, both Boeing’s Advanced Super Hornet and Silent Eagle proposals incorporate CFTs and are able to maintain a relatively low RCS. If the addition of CTFs does not degrade the frontal RCS of the F-22C significantly beyond that of the F-35, it might be appropriate to use in moderately contested threat environments; it would not be used in highly contested SEAD/DEAD missions against near-peer competitors.

Availability Rates & Sustainment

            Banal details related to maintenance, repair, and overhaul (MRO) programs and their impact fleet readiness is a dimension of defense analysis that is often lost upon most armchair generals. Despite the unmatched air-to-air capabilities of each individual F-22 and the extensive training of each Raptor pilot, the small fleet of primary aircraft inventory airframes (PMAI) translates into an even smaller number of planes which are ready for combat at any one time. For example, the USAF has two broad terms to describe an aircraft fleet’s readiness: mission capable rates and availability rates. Mission capable rates (MCR) are equal to the mission capable hours divided by the unit possessed hours while the mission availability rate is equal to the mission capable hours divided by the total aircraft inventory (TAI) hours; MCR is generally a satisfactory level of determining readiness at the unit level while availability rates are indicative of broader fleet level readiness.[13] For example, of the 183 F-22s in the USAF inventory, on average roughly 115 are airworthy and able to execute assigned missions at any one time with an availability rate of 62.8%, the corresponding mission capable rate for the PMAI F-22 component fleet is 72.7% or roughly 89 of 123 PMAI aircraft would be ready to execute missions at any one time.[14][15]

Image 6: Image Credit GAO, 2014. 

            The U.S. can effectively increase its fleet of deployed F-22s by improving readiness rates such that the existing limit fleet size translates into the most combat capability possible. For example, a 10% improvement in MCR among PMAI aircraft would effectively boost the available PMAI fleet size by 13 aircraft – more than half a squadron worth, to a total of 102 up from 89. With such a small fleet size and the prospect of restarting production low, ensuring maximum fleet readiness is vital given the F-22’s unique role as the only high-end survivable air superiority asset in the USAF inventory for the foreseeable future. The USAF has a goal of achieving a fleet availability rate of 70% by 2018 up from the current 62.8% through the reliability and maintainability maturation program (RAMMP). RAAMP modifications include:

Mighty Tough Boot Development [toughens the seams between aircraft panels to facilitate easier maintenance and mitigate damage to RAM coatings], Aircraft Mounted Nozzle Shield (AMNS) Liner Redesign, Integrated Forebody (IFB) Rain Erosion Nose Cap, Canopy Topcoat Redesign, Stored Energy System (SES) Air Filter, Auxiliary Power Unit (APU) Plenum Sealing, Gland Redesign, Automated Backup Oxygen System, Secondary Multi-Function Display (SMFD) Backlight to Lower Power LED, Gland Redesign, and Driver B RF Circuit Redesign[16][17]

Image 7: RAMMP. Image Credit: Flight Global. 

According to Lockheed Martin, 50% of all maintenance activities for the F-22 relate to maintaining its RAM coatings. The limited resilience of the F-22’s RAM coatings contributes towards its astronomically high cost per flight hour to operate at $59,166 compared to $20,318 for the F-16 and $32,000 (projected) for the F-35 as of 2015 data.[18] A total of $1.7 billion will be spent on RAAMP associated upgrades through 2020, but additional modifications – particularly to the F-22’s RAM, are likely required and ought to be incorporated to any F-22C.

Part III will detail capability improvements such as enclosed weapon pods, HMD, IRST, etc. 

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[1] http://www.globalsecurity.org/military/systems/aircraft/f-22-avionics.htm

[2]http://www.mecatronica.eesc.usp.br/wiki/upload/8/8a/2001_The_Avionics_Handbook_SPITZER.pdf

[3] http://www.wsj.com/articles/SB124787043032160493

[4] http://www.intelligent-aerospace.com/articles/2016/02/ia-f22-cni.html

[5]http://www.mecatronica.eesc.usp.br/wiki/upload/8/8a/2001_The_Avionics_Handbook_SPITZER.pdf

[6] http://www.defenseindustrydaily.com/f-22-raptor-capabilities-and-controversies-019069/

[7] http://www.saffm.hq.af.mil/shared/media/document/AFD-160208-052.pdf pp.415

[8] http://www.saffm.hq.af.mil/shared/media/document/AFD-160208-052.pdf pp.418

[9] http://aviationweek.com/defense/ge-details-sixth-generation-adaptive-fighter-engine-plan

[10] Ibid.

[11] Ibid.

[12] https://www.flightglobal.com/news/articles/israel-to-boost-range-of-future-f-35-fleet-220748/

[13] http://www.sae.org/events/dod/presentations/2007LtColJeffMeserve.pdf

[14] http://www.militarytimes.com/story/military/archives/2014/10/14/race-against-time-more-people-money-needed-to-keep-aging/78549006/

[15] http://www.gao.gov/assets/670/663196.pdf

[16] http://www.globalsecurity.org/military/library/budget/fy2015/usaf-peds/0207138f_7_pb_2015.pdf pp.8 

[17] http://www.lockheedmartin.com/us/products/f22/f-22-sustainment.html

[18] https://www.flightglobal.com/news/articles/f-35a-cost-and-readiness-data-improves-in-2015-as-fl-421499/

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[i] Assumes 3,000 pounds additional fuel from CTFs and 25% greater fuel efficiency from variable cycle engines. Does not factor drag or other important factors i.e. this is a “napkin math” type calculation that provides a rough estimate of expected performance.