Editing Sukhoi Su-27 (section)

== Development ==
{{More citations needed section|date=March 2009}}
[[File:Sukhoi T-10 Flanker-A 10 blue (9987131666).jpg|thumb|Prototype Sukhoi T-10]]
In 1969, the Soviet Union learned of the [[United States Air Force|U.S. Air Force]]'s "F-X" program, which resulted in the [[McDonnell Douglas F-15 Eagle|F-15 Eagle]]. The Soviet leadership soon realized that the new American fighter would represent a serious technological advantage over existing Soviet fighters. "What was needed was a better-balanced fighter with both good agility and sophisticated systems." In response, the Soviet General Staff issued a requirement for a ''Perspektivnyy Frontovoy Istrebitel'' (''PFI'', literally "Prospective Frontline Fighter", roughly "Advanced Frontline Fighter").<ref name="Great Book">{{cite book |editor-last=Spick |editor-first=Mike |date=2000 |title=Great Book of Modern Warplanes |chapter=The Flanker |location=Osceola, WI |publisher=MBI Publishing |isbn=0-7603-0893-4}}</ref> Specifications were extremely ambitious, calling for long-range, good short-field performance (including the ability to use austere runways), excellent agility, Mach 2+ speed, and heavy armament. The aerodynamic design for the new aircraft was largely carried out by [[TsAGI]] in collaboration with the [[Sukhoi]] design bureau.<ref name="Great Book" />

When the specification proved too challenging and costly for a single aircraft in the number needed, the PFI specification was split into two: the ''LPFI'' (''Lyogkyi PFI'', Lightweight PFI) and the ''TPFI'' (''Tyazholyi PFI'', Heavy PFI). The LPFI program resulted in the [[Mikoyan MiG-29]], a relatively short-range tactical fighter, while the TPFI program was assigned to Sukhoi OKB, which eventually produced the Su-27 and its various derivatives.

The Sukhoi design, which was altered progressively to reflect Soviet awareness of the [[F-15]]'s specifications, emerged as the ''T-10'' (Sukhoi's 10th design), which first flew on 20 May 1977. The aircraft had a large wing, clipped, with two separate [[nacelle|podded]] engines and a [[twin tail]]. The 'tunnel' between the two engines, as on the [[F-14 Tomcat]], acts both as an additional lifting surface and hides armament from radar.

The T-10 was influenced by the [[Sukhoi|Sukhoi Aircraft Design Bureau]] (Su-ADB), [[Central Aerohydrodynamic Institute|Central Aero-Hydrodynamic Institute]] TsAGI and the [[Chaplygin Siberian Scientific Research Institute Of Aviation|Siberian Aviation Research Institute]] SibNIA in their development of a new aerodynamic scheme labelled the 'integral scheme', where the aircraft would have optimal performance under a [[Instability|longitudinal unstability]] of 3-5% mean aerodynamic [[Chord (aeronautics)|chord]] while flying in [[Subsonic speed|subsonic regimes]] as well as [[Fly-by-wire|fly by wire (FBW)]] for future heavy fighters. Stability problems present in the development of airframes under similar performance demands such as the [[Lockheed YF-22|YF-22]] and [[Saab JAS 39 Gripen|JAS-39 Gripen]] were rectified during the FBW development process through limitation of [[Load factor (aeronautics)|normal load factor]] and [[angle of attack]]. Controlled high angle of attack maneuverability, known as [[supermaneuverability]], was emphasized after a 1980s study by research teams from Su-ADB and TsAGI showing its effectiveness in [[Dogfight|close combat]].<ref>{{Cite web |last=Pogossyan Simonov2 Zaiganov3 Tarasov4 |first=Mickhail Mickhail2 German3 Alexy4 |date=2002 |title=Generation of Su-27 Fighter |url=https://www.icas.org/icas_archive/ICAS2002/PAPERS/R72.PDF |access-date=2025-01-30 |website=icas.org}}</ref>

=== Air Force ===
[[File:Su-27 05.jpg|thumb|left|Soviet Su-27 in flight]]
[[File:P-42 at Ramenskoye.jpg|thumb|P-42 at Ramenskoye airfield]]
The T-10 was spotted by Western observers initially in satellite photographs at [[Gromov Flight Research Institute|Ramenskoye air base]], where it was first called "''Ram-K''" and later assigned the [[NATO reporting name]] 'Flanker-A'. The development of the T-10 was marked by considerable problems, leading to a fatal crash of the second prototype, the T-10-2 on 7 July 1978,<ref>{{cite web |url=http://www.milavia.net/aircraft/su-27/su-27_history.htm |title=Aircraft - Sukhoi Su-27 Flanker Historical Events & Key Dates |first=Niels |last=Hillebrand |website=Milavia |access-date=8 July 2011 |archive-url=https://web.archive.org/web/20110809212601/http://www.milavia.net/aircraft/su-27/su-27_history.htm |archive-date=9 August 2011 |url-status=live}}</ref> due to shortcomings in the [[fly-by-wire]] control system.<ref>{{cite web |url=http://su-27flanker.com/versions/t-10-flanker-a/ |title=Prototype of Su-27 and whole Flanker family – T-10 Flanker A |website=SU-27 Flanker.com |access-date=6 August 2015 |archive-url=https://web.archive.org/web/20150817041202/http://su-27flanker.com/versions/t-10-flanker-a/ |archive-date=17 August 2015 |url-status=dead}}</ref> Extensive redesigns followed (T-10-3 through T-10-15) and a revised version of the T-10-7, now designated the ''T-10S'', made its first flight on 20 April 1981. It also crashed due to control problems and was replaced by T-10-12 which became ''T-10S-2''. This one also crashed on 23 December 1981 during a high-speed test, killing the pilot.<ref>{{cite web |title=Prototype of Su-27 and whole Flanker family – T-10 Flanker A |url=http://su-27flanker.com/versions/t-10-flanker-a |website=Su-27 Flanker.com |access-date=5 March 2015 |archive-url=https://web.archive.org/web/20150314230408/http://su-27flanker.com/versions/t-10-flanker-a/ |archive-date=14 March 2015 |url-status=dead}}</ref> Eventually the T-10-15 demonstrator, ''T-10S-3'', evolved into the definitive Su-27 configuration.<ref>{{cite journal |last1=Kopp |first1=Dr. Carlo |url=http://www.ausairpower.net/APA-Flanker.html |title=Sukhoi Flankers: The Shifting Balance of Regional Air Power (Technical Report APA-TR-2007-0101) |website=Air Power Australia |date=7 January 2007 |pages=1 |access-date=5 March 2015 |archive-url=https://web.archive.org/web/20071226195336/http://www.ausairpower.net/APA-Flanker.html |archive-date=26 December 2007 |url-status=live}}</ref>

The ''T-10S-3'' was modified and officially designated the ''P-42'', setting a number of [[Viktor Pugachyov#Record flights|world records for time-to-height]],<ref>{{Cite web |url=https://www.youtube.com/watch?v=07tEk-9j69I |title=The fastest climb in aviation history. Climbing time record of the Su-27 to an altitude of 12 km |date=5 July 2020 |website=YouTube |access-date=8 December 2020 |archive-date=9 July 2021 |archive-url=https://web.archive.org/web/20210709201016/https://www.youtube.com/watch?v=07tEk-9j69I |url-status=live }}</ref> beating those set in 1975 by a [[McDonnell Douglas F-15 Eagle#Research and test|similarly modified F-15]] called "The Streak Eagle".<ref>{{cite web |title=40 Years Ago, 'Streak Eagle' Smashed Records for 'Time to Climb' |url=http://www.utc.com/News/PW/Pages/40-Years-Ago-Streak-Eagle-Smashed-Records-for-Time-to-Climb.aspx |website=[[United Technologies]] Corp. |access-date=6 March 2015 |archive-url=https://web.archive.org/web/20150402122156/http://www.utc.com/News/PW/Pages/40-Years-Ago-Streak-Eagle-Smashed-Records-for-Time-to-Climb.aspx |archive-date=2 April 2015 |url-status=dead}}</ref> The ''P-42'' "Streak Flanker" was stripped of all armament, radar and operational equipment. The fin tips, tail-boom and the wingtip launch rails were also removed. The composite radome was replaced by a lighter metal version. The aircraft was stripped of paint, polished and all drag-producing gaps and joints were sealed. The engines were modified to deliver an increase in thrust of {{convert|1000|kg|abbr=on}}, resulting in a [[thrust-to-weight ratio]] of almost 2:1 (for comparison with standard example see [[#Specifications (Su-27SK)|Specifications]]).<ref>{{cite web |title=P-42 Record Flanker |url=http://www.propro.ru/flankers/eng/su-27.htm#p42 |website=ProPro Group |access-date=6 March 2015 |archive-url=https://web.archive.org/web/20150312181931/http://propro.ru/flankers/eng/Su-27.htm#p42 |archive-date=12 March 2015 |url-status=dead}}</ref><ref>{{cite book |last1=Winchester |first1=Jim |title=Jet fighters : inside & out |date=2012 |publisher=Rosen Pub. |location=New York |isbn=978-1-4488-5982-5 |page=130 |url=https://books.google.com/books?id=3shgcJXesN0C&pg=PA130 |access-date=6 March 2015 |archive-url=https://web.archive.org/web/20150402201416/https://books.google.com.au/books?id=3shgcJXesN0C&pg=PA130 |archive-date=2 April 2015 |url-status=live}}</ref>

[[File:Sukhoi Su-27UB ’17 red’ (37514194274).jpg|thumb|Twin-seat combat trainer Su-27UB of the [[Russian Aerospace Forces]]]]
The production ''Su-27'' (sometimes ''Su-27S'', NATO designation 'Flanker-B') began to enter [[Soviet Air Forces|VVS]] operational service in 1985, although manufacturing difficulties kept it from appearing in strength until 1990.<ref name="SU27SKhistory">{{cite web |url=http://www.sukhoi.org/eng/planes/military/su27sk/history/ |title=Airplanes - Military Aircraft - Su-27SÊ - Historical background |website=Sukhoi Company (JSC) |access-date=4 February 2015 |archive-url=https://web.archive.org/web/20150214080912/http://www.sukhoi.org/eng/planes/military/su27sk/history/ |archive-date=14 February 2015 |url-status=dead}}</ref> The Su-27 served with both the [[Soviet Air Defence Forces|V-PVO]] and Frontal Aviation. Operational conversion of units to the type occurred using the ''Su-27UB'' (Russian for ''Uchebno Boevoy'' - "combat trainer", NATO designation 'Flanker-C') twin-seat trainer, with the pilots seated in tandem.<ref name="www.nationalmuseum.af.mil">{{cite web |last1=Zettlemoyer |first1=Ryan |title=Sukhoi SU-27UB "FLANKER-C" TRAINER |url=https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/3566120/sukhoi-su-27ub-flanker-c-trainer/ |website=www.nationalmuseum.af.mil |access-date=6 July 2024 |ref=National Museum Of The United States Air Force}}</ref>

When the naval Flanker trainer was being conceived the Soviet Air Force was evaluating a replacement for the [[Sukhoi Su-24|Su-24 "Fencer"]] strike aircraft, and it became evident to Soviet planners at the time that a replacement for the Su-24 would need to be capable of surviving engagements with the new American F-15 and F-16. The Sukhoi bureau concentrated on adaptations of the standard ''Su-27UB'' tandem-seat trainer. However, the Soviet Air Force favoured the crew station (side-by-side seating) approach used in the Su-24 as it worked better for the high workload and potentially long endurance strike roles. Therefore, the conceptual naval [[Trainer (aircraft)#Tandem and side by side|side-by-side seated trainer]] was used as the basis for development of the ''Su-27IB'' (Russian for ''Istrebityel Bombardirovshchik'' - "fighter bomber") as an Su-24 replacement in 1983. The first production airframe was flown in early 1994 and renamed the ''Su-34'' (NATO reporting name 'Fullback').<ref name="auto">{{cite journal |last1=Kopp |first1=Dr. Carlo |title=Sukhoi Su-34 Fullback: Russia's New Heavy Strike Fighter (Technical Report APA-TR-2007-0108) |url=http://www.ausairpower.net/APA-Fullback.html |website=Air Power Australia |date=April 2012 |pages=1 |access-date=19 March 2015 |archive-url=https://web.archive.org/web/20150317021534/http://www.ausairpower.net/APA-Fullback.html |archive-date=17 March 2015 |url-status=live}}</ref>

=== Navy ===
[[File:The 279th separate naval fighter regiment (Murmansk Region) (26).jpg|thumb|A [[Su-33]] on approach]]
Development of a version for the Soviet Navy designated ''Su-27K'' (from ''Korabyelny'' - "shipborne", NATO designation 'Flanker-D') commenced not long after the development of the main land-based type. Some of the T-10 demonstrators were modified to test features of navalized variants for carrier operations. These modified demonstrators led to specific prototypes for the Soviet Navy, designated "''T-10K''". The T-10Ks had [[canard (aeronautics)|canards]], an [[Tailhook|arresting hook]] and carrier landing avionics as well as a retractable inflight refueling probe. They did not have the landing gear required for carrier landings or folding wings. The first T-10K flew in August 1987 flown by the famous Soviet test pilot [[Viktor Pugachev]] (who first demonstrated the [[Cobra maneuver]] using an Su-27 in 1989), performing test takeoffs from a land-based [[Flight deck#Ski-jump ramp|ski-jump]] carrier deck on the [[Black Sea]] coast at [[Saky]] in the [[Ukrainian Soviet Socialist Republic|Ukrainian SSR]]. The aircraft was lost in an accident in 1988.

At the time the naval Flanker was being developed the Soviets were building their first generation of [[aircraft carriers]] and had no experience with [[Aircraft catapult|steam catapults]] and did not want to delay the introduction of the carriers. Thus it was decided to use a takeoff method that did not require catapults by building up full thrust against a blast deflector until the aircraft sheared restraints holding it down to the deck. The fighter would then accelerate up the deck onto a ski jump and become airborne.<ref>{{cite web |last1=Goebel |first1=Greg |title=[1.0] First-Generation Su-27s - [1.5] Naval Su-27K (Su-33) |url=http://www.airvectors.net/avsu27_1.html#m5 |website=AirVectors.net |access-date=8 March 2015 |archive-url=https://web.archive.org/web/20141129032144/http://www.airvectors.net/avsu27_1.html#m5 |archive-date=29 November 2014 |url-status=live}}</ref>

The production ''Su-27K'' featured the required strengthened landing gear with a two-wheel nose gear assembly, folding [[stabilator]]s and wings, outer [[aileron]]s that extended further with inner double slotted [[Flap (aeronautics)|flaps]] and enlarged [[leading-edge slats]] for low-speed carrier approaches, modified [[Leading-edge extension|leading edge root extension]] (LERX) with canards, a modified ejection seat angle, upgraded fly-by-wire, upgraded hydraulics, an arresting hook and retractable inflight refuelling probe with a pair of deployable floodlights in the nose to illuminate the [[Ilyushin Il-78|tanker]] at night. The Su-27K began carrier trials in November 1989, again with Pugachev at the controls, onboard the first Soviet aircraft carrier, called ''[[Russian aircraft carrier Admiral Kuznetsov|Tbilisi]]'' at the time and formal carrier operations commenced in September 1991.<ref>{{cite journal |last1=Kopp |first1=Dr Carlo |title=Sukhoi Su-33 and Su-33UB Flanker D Shenyang J-15 Flanker D (Technical Report APA-TR-2008-0603) |url=http://www.ausairpower.net/APA-Maritime-Flanker-D.html |website=Air Power Australia |date=25 June 2008 |pages=1 |access-date=8 March 2015 |archive-url=https://web.archive.org/web/20150416015653/http://www.ausairpower.net/APA-Maritime-Flanker-D.html |archive-date=16 April 2015 |url-status=live}}</ref><ref>{{cite web |title=Kuznetsov class heavy aviation cruiser |url=http://www.military-today.com/navy/kuznetsov_class.htm |website=Military-Today.com |access-date=8 March 2015 |archive-url=https://web.archive.org/web/20150309080724/http://www.military-today.com/navy/kuznetsov_class.htm |archive-date=9 March 2015 |url-status=usurped}}</ref>

Development of the naval trainer, called the ''Su-27KUB'' (from ''Korabyelny Uchebno-Boyevoy'' - "shipborne trainer-combat"), began in 1989. The aim was to produce an airframe with dual roles for the Navy and Air Force suitable for a range of other missions such as reconnaissance, aerial refuelling, maritime strike, and jamming. This concept then evolved into the ''Su-27IB'' ([[Sukhoi Su-34|Su-34 "Fullback"]]) for the Soviet Air Force. The naval trainer had a revised forward fuselage to accommodate a side-by-side cockpit seating arrangement with crew access via a ladder in the nose-wheel undercarriage and enlarged canards, stabilisers, fins and rudders. The wings had extra ordnance hardpoints and the fold position was also moved further outboard. The inlets were fixed and did not feature [[foreign object damage]] suppression hardware. The central fuselage was strengthened to accommodate {{convert|45|t|lb|abbr=off}} maximum gross weight and internal volume was increased by 30%. This first prototype, the T-10V-1, flew in April 1990 conducting aerial refuelling trials and simulated carrier landing approaches on the Tbilisi. The second prototype, the T-10V-2 was built in 1993 and had enlarged internal fuel tanks, enlarged spine, lengthened tail and tandem dual wheel main undercarriage.<ref name="auto"/>

=== Export and post-Soviet development ===
In 1991, the production facilities at [[Komsomolsk-on-Amur Aircraft Plant]] and [[Irkutsk]] developed export variants of the Su-27: the ''Su-27SK'' single seat fighter and ''Su-27UBK'' twin-seat trainer, (the ''K'' in both variants is Russian for "'''K'''ommercheskiy" - literally "Commercial")<ref name="Global Security">{{cite web |last1=Zettlemoyer |first1=Ryan |title=Su-27UBK FLANKER |url=https://www.globalsecurity.org/military/world/russia/su-27ubk.htm |website=Global Security |access-date=7 July 2024 |ref=Global Security}}</ref> which have been exported to [[China]], [[Vietnam]], [[Ethiopia]] and [[Indonesia]].<ref name="ODIN">{{cite web |last1=Zettlemoyer |first1=Ryan |title=Su-27 (Flanker) Russian Multirole Fighter Aircraft |url=https://odin.tradoc.army.mil/WEG/Asset/Su-27_(Flanker)_Russian_Multirole_Fighter_Aircraft |website=odin.tradoc.army |publisher=The United States Army |access-date=7 July 2024 |ref=ODIN}}</ref>
After the [[Dissolution of the Soviet Union|collapse of the USSR]] in 1991, [[Russia]], the successor state, started development of advanced variants of the Su-27 including the [[Sukhoi Su-30|Su-30]], [[Sukhoi Su-33|Su-33]], Su-34, [[Sukhoi Su-35|Su-35]], and [[Sukhoi Su-37|Su-37]].

Since 1998 the export ''Su-27SK'' has been produced as the [[Shenyang J-11]] in China under licence. The first licensed-production plane, [[Shenyang Aircraft Corporation|assembled in Shenyang]] from Russian supplied kits, was flight tested on 16 December 1998. These licence-built versions, which numbered 100, were designated J-11A. The next model, the J-11B made extensive use of Chinese developed systems within the ''Su-27SK'' airframe.<ref>{{cite journal |last1=Kopp |first1=Dr Carlo |title=PLA-AF and PLA-N Flanker Variants (Technical Report APA-TR-2012-0401) |url=http://www.ausairpower.net/APA-PLA-Flanker-Variants.html |website=Air Power Australia |date=7 April 2012 |pages=1 |access-date=7 March 2015 |archive-url=https://web.archive.org/web/20181215122009/http://www.ausairpower.net/APA-PLA-Flanker-Variants.html |archive-date=15 December 2018 |url-status=live}}</ref>

{{Anchor|Sukhoi Su-27SM}}
Starting in 2004, the Russian Air Force began a major update of the original Soviet Su-27 ('Flanker-B') fleet. The upgraded variants were designated ''Su-27SM'' (Russian for "'''S'''eriyniy '''M'''odernizovanniy" - literally "'''S'''erial '''M'''odernized"). This included upgrades in air-to-air capability with the [[R-77]] missile with an active radar homing head. The modernized Su-27SM fighters belong to the [[Fourth-generation jet fighter|4+ generation]]. The strike capability was enhanced with the addition of the [[Kh-29|Kh-29T/TE/L]] and [[AS-17 Krypton|Kh-31P/Kh-31A]] [[Air-to-surface missile|ASM]] and [[KAB-500KR|KAB-500KR/KAB-1500KR]] smart bombs. The avionics were also upgraded.<ref name="Air Vectors">{{cite web |last1=Zettlemoyer |first1=Ryan |title=[2.0] Second-Generation Su-27s & Derivatives |url=https://www.airvectors.net/avsu27_2.html |website=Air Vectors |access-date=7 July 2024 |ref=Air Vectors}}</ref> The Russian Air Force is currently receiving aircraft modernized to the SM3 standard. The aircraft’s efficiency to hit air and ground targets has increased 2 and 3 times than in the basic Su-27 variant. Su-27SM3 has two additional stations under the wing and a much stronger airframe. The aircraft is equipped with new onboard radio-electronic systems and a wider range of applicable air weapons. The aircraft’s cockpit has multifunctional displays.<ref>{{cite web |url=http://www.airrecognition.com/index.php/archive-world-worldwide-news-air-force-aviation-aerospace-air-military-defence-industry/global-defense-security-news/global-news-2018/november/4644-russian-air-force-sets-up-new-su-27sm3-wing.html |title=Russian Air Force sets up new Su-27SM3 wing |date=November 2018 |website=AirRecognition.com |access-date=2 February 2019 |archive-url=https://web.archive.org/web/20181122172058/http://www.airrecognition.com/index.php/archive-world-worldwide-news-air-force-aviation-aerospace-air-military-defence-industry/global-defense-security-news/global-news-2018/november/4644-russian-air-force-sets-up-new-su-27sm3-wing.html |archive-date=22 November 2018 |url-status=live}}</ref>

The Su-30 is a two-seat multi-role version developed from the ''Su-27UBK'' and was designed for export and evolved into two main variants. The export variant for China, the [[Sukhoi Su-30MKK|''SU-30MKK'']] ('Flanker-G') which first flew in 1999. The other variant developed as the export version for India, the [[Sukhoi Su-30MKI|''Su-30MKI'']] ('Flanker-H') was delivered in 2002 and has at least five other configurations.

The Su-33 is the Russian Navy version of the Soviet ''Su-27K'' which was redesignated by the Sukhoi Design Bureau after 1991. Both have the NATO designation 'Flanker-D'.

The Su-34 is the Russian derivative of the Soviet-era ''Su-27IB'', which evolved from the Soviet Navy ''Su-27KUB'' operational conversion trainer. It was previously referred to as the ''Su-32MF''.

The newest and most advanced version of the Su-27 is the [[Sukhoi Su-35#Modernization|Su-35S]] ("'''S'''erial"). The Su-35 was previously referred to as the ''Su-27M'', ''Su-27SM2'', and ''Su-35BM''.<ref>{{cite web |last1=Katz |first1=Dan |title=Program Dossier - Sukhoi Flanker |url=http://aviationweek.com/site-files/aviationweek.com/files/uploads/2014/11/asd_11_14_2014_Flanker6.pdf |website=Aviation Week |access-date=7 March 2015 |archive-url=https://web.archive.org/web/20150402101322/http://aviationweek.com/site-files/aviationweek.com/files/uploads/2014/11/asd_11_14_2014_Flanker6.pdf |archive-date=2 April 2015 |url-status=dead}}</ref>

The Su-37 is an advanced technology demonstrator derived from Su-35 prototypes, featuring thrust vectoring nozzles made of [[Titanium#Aerospace and marine|titanium]] rather than steel and an updated airframe containing a high proportion of [[Carbon-fiber-reinforced polymer|carbon-fibre]] and [[Aluminium-lithium alloy|Al-Li alloy]].<ref>{{cite web |title=Su-37 |url=https://fas.org/man/dod-101/sys/ac/row/su-37.htm |first=John |last=Pike |date=March 11, 1999 |website=Federation of American Scientists |access-date=21 March 2015 |archive-url=https://web.archive.org/web/20150402112523/http://fas.org/man/dod-101/sys/ac/row/su-37.htm |archive-date=2 April 2015 |url-status=live}}</ref> Only two examples were built and in 2002 one crashed, effectively ending the program. The Su-37 improvements did however make it into new Flanker variants such as the ''Su-35S'' and the ''Su-30MKI''.<ref>{{cite web |title=Su-37 Flanker-F Fighter, Russia |url=http://www.airforce-technology.com/projects/su37/ |website=Airforce-Technology.com |access-date=21 March 2015 |archive-url=https://web.archive.org/web/20150313004737/http://www.airforce-technology.com/projects/su37 |archive-date=13 March 2015 |url-status=live}}</ref><!-- {{Unreliable source?|reason=domain on WP:BLACKLIST |date=June 2016}} -->