The EG (also known as the Yak-M-11-FR-1, Sh or Yak-EG) was a prototype helicopter designed in 1946 by the Yakovlev OKB. The EG was designed with a coaxial rotor configuration and had an ambitious performance estimation. Through manufacturer testing, it was revealed that the EG had very undesirable handling characteristics and excessive vibrations when the helicopter reached around 20 mph (30 km/h). These flaws caused the cancellation of the EG project and the completed prototype was converted to an aerosani in 1955 and donated to a farm in the Kazakh SSR. The Kamov OKB would later go on to develop the coaxial rotor configuration further.
History
Lessons of the Second World War showed the world the importance of adopting and developing modern technologies. Throughout the war, autogyros and helicopters became increasingly relevant with several countries’ militaries and saw a dramatic increase in development. The Soviet Union had a very limited selection of these machines during the war, and looked to develop this technology and expand their arsenal. In 1946, the esteemed Yakovlev OKB initiated a project for an experimental coaxial rotor helicopter design. The project was given the nickname of “EG”, for “Experimental Helicopter” (Экспериментальный Геликоптер / Eksperimentahl’nyy ghelikopter). When the task of designing the EG was first announced to the design team, a flabbergasted staff member exclaimed “Shootka?” (шутыш), which roughly translates to “Are you kidding?”. This then led the EG to unofficially be referred to as the “Sh”, a running joke in the design team. Another designation which referred to the EG was “Yak-M-11FR-1”, which referred to the engine that the helicopter would use. The origin of this designation is unknown, but it does not appear to be official.
Responsibility over the project was given to chief designer S.A. Bemov, with I.A. Erlikh as his aide. The EG was envisioned as a coaxial rotor configuration while powered by a 5-cylinder air-cooled Shvetsov M-11FR-1 radial engine producing 140 hp. When the initial design was completed in early 1947, the design team built a flying scale model of the EG to prove the viability of the coaxial rotor design. The scale model was given the designation of ED 115, with the digits referencing OKB-115, the plant designation for Yakovlev OKB.
After verifying the EG’s design, construction of the actual prototype commenced. The prototype was completed sometime in the summer of 1947 and was promptly subjected to manufacturer’s trials. The EG prototype performed 40 tethered flights (total of 5 hours flight time) before being authorized to perform the first free flight test on December 20, 1947. Through extensive testing, it was revealed that the center of gravity was too far to the rear, which led the team to remove the tail and tailskid and relocate the oil tank behind the cockpit. In early 1948, the M-11FR-1 engine was removed, replace by an experimental M-12 radial engine, a development of the M-11. The first test flight with this engine was conducted on April 9th, but the engine proved troublesome and forced the team to refit the M-11FR-1 engine. Flight tests continued until July 8, 1948, with a total of 75 free flights conducted (total of 15 hours flight time).
Despite the EG showing relatively decent results, it suffered from excessive vibration, loss of stick force and phugoid instability once the machine approached 20 mph (30 km/h). This severely restricted the EG’s practicality and thus warranted the project’s cancellation. The coaxial rotor design configuration was given to Kamov OKB to further develop, while the Yakovlev OKB moved onto more conventional helicopter configurations. A second prototype was in construction but was never completed and was scrapped when the program was canceled. The sole completed prototype was preserved at the Moscow Aviation Institute for a couple of years before being converted to an aero-sleigh by students between 1954 and 1955. The converted sleigh was then donated to a farm in the Kazakh SSR and the fate beyond that is unknown. Photos of this new conversion do not exist. Though ultimately ending up as a failure, the EG was an important stepping stone in Soviet helicopter development and was quite special in the sense that it was the Yakovlev OKB’s first helicopter design.
Design
The Yakovlev EG was a coaxial rotor helicopter powered by a 5-cylinder air-cooled Shvetsov M-11FR-1 radial engine producing 140 hp. The engine drove co-axial two-bladed rotors using a transmission system which featured a centrifugal clutch, a 90-degree gearbox and a cooling fan. Fuel tanks were placed under the gearbox while the oil tank was next to the engine. The rotors (made of laminated pine and hardwood) spun in opposite directions at 233 rpm. Both collective and cyclic pitch control was provided through the rotor’s fully articulated hub mount. The EG’s fuselage consisted of simple welded steel tubes which had D1 duraluminium skin all around except for the engine compartment. The rear fuselage, which was covered with fabric, gradually tapered off to form a fin which was accompanied by a horizontal stabilizer supplemented by two endplate tips. The tail and the horizontal stabilizer would be removed later on in the test phase due to the offset center of gravity. The EG had a non-retractable tricycle landing gear with vertical shock absorber struts. The glazed cockpit compartment could house two pilots, which would enter through doors on either side of the fuselage.
Operators
Soviet Union – The Yakovlev EG was designed with the intent of serving the Soviet Union. The EG was evaluated by Yakovlev OKB but was deemed to be unfit for service due to the excessive vibration and loss of stick control and phugoid instability when the helicopter reached speeds around 20 mph (30 km/h).
The Yakovlev Yak-10 was a four-seat multipurpose light aircraft designed in 1944 as a replacement for the Polikarpov U-2 (Po-2), a biplane which served as a liaison and passenger transport aircraft. Although the Yak-10 successfully passed state acceptance trials in January of 1945, it proved rather unsatisfactory with Soviet Air Force pilots, and thus, only 41 examples, including the prototype, were produced in 1946 before being replaced by the redesigned and superior Yak-12 light aircraft in 1947. Though unsuccessful in service, the Yak-10 provided valuable experience in light aircraft design and served as a stepping stone for the more successful Yak-12.
History
In early 1944, the Soviet High Command was beginning to realize the obsolete nature of the Polikarpov U-2 (Po-2) in its liaison role. In the wake of the quickly advancing aircraft industry, Yakovlev OKB (Experimental Design Bureau) was called upon to design a multipurpose light aircraft capable of performing liaison missions, ferrying passengers, cargo, and aerial ambulance duties for the Air Force to replace the Po-2. In response, Yakovlev OKB initiated a project with G.I. Gudimenko assigned as chief engineer and work commenced on a four-seat, high-wing monoplane using the firm’s pre-war AIR-6 design as a basis, which had similar traits. The new aircraft design was assigned the designation of Yak-14.
Due to the rather obscure nature of the project’s development, it is unknown when the first prototype was produced, but it is most likely sometime before or in early January of 1945. First flown by test pilot F.L. Abramov, the Yak-14, powered by a 5-cylinder, air cooled Shvetsov M-11FM radial engine producing 145 hp, proved to have unacceptable handling characteristics. This prompted minor redesigning and modifications to the prototype which would address the issues that emerged from the test flight. Amongst the various modifications, the aircraft was also redesignated as the Yak-10 (the Yak-14 designation would later be reused for a 1947 assault glider project). With the completion of modifications, the Yak-10 was resubmitted for state testing. The aforementioned handling characteristic issues appeared to have been addressed, and the Yak-10 passed state trials in June of 1945.
Now authorized for service, production of the Yak-10 was assigned to the No. 464 aircraft plant in Dolgoprudny (Долгопру́дный), approximately 12 mi / 20 km north of Moscow. A total of 40 models were produced in 1946, which were then delivered to air force units. An important difference between the prototype and production models was the conversion from the 145 hp M-11FM engine to the 160 hp M-11FR engine. During the Yak-10’s service life, several variants were designed. These included a dual-control trainer variant known as the Yak-10V, an aerial ambulance variant capable of carrying two stretchers and a doctor known as the Yak-10S, an experimental floatplane variant known as the Yak-10G, and an experimental ski landing gear conversion without a proper designation. Due to the scarcity of documents regarding the Yak-10, it is unknown how many Yak-10V and Yak-10S models were produced, but the Yak-10G and Yak-10 with ski gear were converted from standard Yak-10 models. Curiously, the Yak-10 also had a competitive experimental low-wing development in 1944 known as the Yak-13 (originally designated the Yak-12, which is unrelated to the 1947 development) which featured a split landing flap and various smaller modifications. Though the Yak-13 was superior to the Yak-10 in speed, the Yak-10 possessed operational advantages and thus won the favor of the Soviet high command. Though the Yak-13 was considered to be produced alongside the Yak-10, the act was deemed economically unviable and thus the Yak-13 remained a one-off prototype.
In Soviet service the Yak-10 proved to be lacking in terms of performance, which also impacted the aircraft’s ability to be adapted to more roles. Within a year of the Yak-10’s fielding, the Yakovlev OKB was once again called upon to produce a better aircraft. In early 1947, the bureau initiated another project to fulfill the demands of the Air Force. G.I. Gudimenko was once again assigned as chief engineer, but now M.A. Shchyerbina, M.N. Beloskurskii and L.L. Selyakov joined the team as designers. The new project was designated as the Yak-12 (recycled from the Yak-13’s initial designation) and was essentially a redesigned Yak-10 that featured a redesigned rear fuselage contour and a shallower upper decking. Along with some other modifications to the wings, structure and fuselage, the Yak-12 would undergo flight testing within the same year. Though slower than the Yak-10 in speed, the Yak-12 proved to be more versatile for other roles and had greater operational characteristics. Such improvement was deemed satisfactory by the Air Force and mass production thus commenced. The success of the Yak-12 overshadowed the Yak-10 and all examples were withdrawn soon afterwards. The Yak-12 would be produced in the thousands with dozens of variants and conversions designed. It would see service with several Eastern Bloc countries, as well as the People’s Republic of China, Mongolia and possibly Cuba (it is unknown if they operated this type). The Yak-12 was saw military service well into the 1970s but were all retired prior to the 21st century. Several Yak-12 models are still flown to today for recreation, airshows and other roles.
The Yak-10, despite passing state acceptance trials, was still an operational failure and saw only limited production. However, the Yak-10 was an important stepping stone in the development of the Yak-12, which was much more successful and had a fruitful service life within the Soviet Union and several other countries.
Design
The Yakovlev Yak-10 was a four-seat, high-wing, single-engine multipurpose light aircraft designed in 1944. The standard production Yak-10 was powered by a 5-cylinder air-cooled Shvetsov M-11FR radial engine providing 160 hp, accompanied by a two blade aluminum VISh-327 propeller. The Yak-10’s fuselage and tail was of metal construction while the wings were wooden. The wooden wings possessed a thickness to chord ratio of 11% and utilized the Clark YH airfoil. The fuselage consisted of a welded tubular steel truss while the tail possessed duralumin frames. Fabric was utilized throughout the entire aircraft for skinning. Twin bracing struts constructed of airfoil section steel tubes joined the wings and fuselage. The Yak-10 also had a non-retractable undercarriage in a taildragger configuration. It consisted of pyramid type, rubber-sprung main units and had a castoring tailwheel.
The Yak-10V dual control trainer variant would have featured a new set of controls next to the regular pilot seat. This would allow a co-pilot to fly while both pilots sat side by side. The Yak-10S ambulance variant would have a hatch on the port side of the fuselage for loading stretchers. A total of two stretchers could be accommodated in the Yak-10S along with a seat for a doctor. The Yak-10G featured the replacement of the conventional landing gear with floats previously used in the Yakovlev OKB’s previous AIR-6 multipurpose light aircraft design. Little is known about this variant, but it is known that it did not go into production due to the loss of performance caused by the floats’ drag. The experimental Yak-10 ski conversion had the landing gear replaced by Canadian manufactured wood skis of 6 ft 3 63/64 in x 1 ft 25/64 in / (1,930 x 340 mm). These skis weighed 44.7 lb (20.25 kg). The tail wheel was also replaced by a ski which measured at 1 ft 6 7/64 in x 4 47/64 in (460 x 120 mm) and weighed 4.25 lb (1.93 kg). This modification caused the aircraft’s performance to deteriorate and proved to be only capable of operating in rolled-down airfields. Consequently, the type was not adopted for use.
Variants
Yak-10 – Standard production variant powered by a 5-cylinder air-cooled Shvetsov M-11FR radial engine providing 160 hp.
Yak-10V – Dual control trainer variant of the Yak-10. An unknown amount were produced.
Yak-10S – Medical variant of the Yak-10 which featured a hatch on the port side of the fuselage for loading stretchers. The passenger compartment could accommodate two stretchers and one doctor. It is unknown how many Yak-10S models were manufactured.
Yak-10G – Experimental floatplane variant of the Yak-10. A single Yak-10 was modified to carry AIR-6 type floats in 1946. The Yak-10G underwent manufacturer’s tests but this type was not accepted for mass production, likely due to the degradation of performance generated by the floats’ drag.
Yak-10 (Skis) – Experimental conversion of a Yak-10 to replace the conventional landing gears with Canadian manufactured wooden skis. A single example was converted from a standard model in February of 1947 but was rejected for service as the skis caused the Yak-10’s performance to deteriorate. The ski variant was also deemed only capable of being operated from rolled-down airfields, thus limiting the operable areas.
Yak-13 – Development of the Yak-10 in 1944 which saw a redesigned low-wing configuration, a split landing flap and various smaller modifications. The engine was also switched to a M-11FM radial engine producing 145 hp. The Yak-13 was superior to the Yak-10 in terms of performance, but this aircraft was not accepted for mass production as the Yak-12 was deemed better in some regards and as a result, the Yak-13 remained a one-off prototype. This variant was originally designated as the Yak-12 but the name was changed to Yak-13 during trials and the designation was reused for the 1947 development project of the Yak-10.
Yak-12 – Redesigned variant which first appeared in 1947. The Yak-12 featured a redesigned rear fuselage contour and a more shallow upper decking. Though the base model was slightly inferior to the Yak-10 in speed, the redesigned variant proved more capable in other aspects and was thus mass produced and replaced the Yak-10 in service.
Operators
Soviet Union – The Yakovlev Yak-10 and it’s variants were briefly operated by the Soviet Air Force from 1946 to 1947 before being replaced by the superior Yak-12.
The Yak-23 emerged as the final step of the Yak-15 and Yak-17 development series. It made its first flight in mid-1947, powered, ironically, by a British Rolls-Royce Derwent jet-engine. By the time it entered production, the engine was changed with a Soviet-built copy. Over 300 were built, but as more advanced planes were ready for service the Yak-23s were sold to several Eastern Bloc countries. There they remained in service until replaced with the MiG-15 in the mid-1950s.
History of the Yak-23 predecessor
The Soviets began developing jet powered aircraft in the 1930s, but the process was slow with no major progress. However, by the end of World War 2, the Soviets managed to come into possession of large quantities of German war technology, engines as well as experimental and operational jet aircraft.
In April 1945, by orders of the National Defense Committee of the Soviet Union, work on a new generation of jet-powered aircraft began. In the case of jet fighters, the minimum requirement was that it had to achieve a maximum top speed of 500 mph (800 km/h). As there were a number of captured German Junkers Jumo 004B1 and BMW 003 jet engines, it was proposed to try to use them in Soviet designs. These received the new Soviet designation RD-10 Reaktinyi Dvitagatel, which is Russian for “jet engine.” The design and work on the first power plant was given to the OKB-117 Experimental Design Bureau, under the designer Vladimir Y. Klimov in late April 1945. A few months later, a second order was given to develop a new RD-20 jet engine based on the German BMW 003 jet engine. As the Soviet scientists were not familiar with this technology, the entire development ran quite slowly. The first series of these engines was ready in 1946, but the performance turned out to be limited and almost useless.
The work on the new jet fighter program was also slow and largely fruitless. Projects like the MiG-13, La-7R and Yak-3RD were built in limited numbers and proved to be unsuccessful. One of the main reasons for so many failed projects was the fact that the Soviet designers used captured and complicated German jet technology as an inspiration. There had to be a change in the way the Soviet designers and engineers approached these technologies and developments. Since time was crucial, the designers were forced to adopt simpler solutions.
Several new projects resulted from these decisions, one of which was the A.S.Yakovlev Yak-Jumo project. It was based on Yakovlev’s own analysis of German technology, especially the light weight, stepped fuselage and the forward position engine design. His first idea was to try to take advantage of the already existing piston engine-powered fighters and, if possible, install one or more jet engines on them. He reused one Yak-3 fighter and modified it to mount one rocket engine instead of the piston engine. Most parts of the Yak-3 were reused, wings, including the whole fuselage, tail surfaces, undercarriage and most in-built systems and equipment. The new engine was fitted in the forward part of the fuselage, but tilted at a 430’ angle with respect to the plane’s axis. Besides this, it was necessary to redesign the whole fuel system. A new redesigned cockpit was installed and the armament would consist of two 23 mm NS-23K autocannons each with 60 rounds of ammunition located above the engine. The German Jumo 004 engine was used and thus the project name was Yak-Jumo or Yak-3 Jumo (depending on the source).
The first prototype was completed and ready by late 1945. During its first several ground tests, many problems were reported. One of them was the excessive heating of the rear lower fuselage caused by the engine exhaust gases. A second complete and improved prototype was built in December 1945. It was equipped with the Soviet-built RD-10 which was a direct copy of the Jumo 004. Tests on the second prototype plane began during the second half of 1946. During these tests, several complaints were noted and the aircraft was returned to the factory in order to resolve these issues. By that time, this plane received a new military designation, the Yak-15.
On 12th September, 1946, an order for a limited production run was given by the Ministry of Aircraft Production. The Yak-15 and MiG-9s were first presented to the public during a military parade held in Moscow’s Red Square of that year.
Due to the rapid development of Western jet aircraft, Soviet military authorities demanded improved and more advanced jet planes. The new fighters had to be able to reach a maximum speed of 620 mph (1,000 km/h), but mostly due to lack of adequate jet engines this was only successfully implemented in later, much more improved models like the MiG-17. This was the reason why some jet fighters were put into production despite much lower top speeds.
Due to obsolescence and new problems discovered during the Yak-15’s service, most were modified to be used as advanced trainers, but some were operated as standard fighters. Yakovlev was again tasked with the development of an improved jet fighter. It was required to have a significantly better aerodynamic layout and was to be powered by an RD-10 engine. Estimated maximum speed was to be around 527 mph (850 km/h) at an altitude of 16.400 ft (5,000 m). Besides this, a novelty was the installation of an ejection seat and armored glass plate for the windscreen. By September 1946, the first Yak-17 was ready for testing. These tests were considered successful, especially by the pilots who considered it to have good flying performance. Serial production was to start in the autumn of 1947. The Yak-17 would be built in relatively small numbers as more advanced designs would replace it in the following years, designs like the Yak-23.
History of the Yak-23
Later development of new Yakovlev aircraft was characterized by several different methods of approaching development. One of the many Yakovlev design teams, lead by Leonid L. Selyakov, worked on a completely new design that would later lead to the Yak-25. The main goal of this project was to build a completely new aircraft. In addition to this team, a second team advocated for the improvement of the already existing Yak-15 and Yak-17 designs.
The second team’s design was a lightweight and with highly maneuverable jet fighter. This new fighter was to be powered by an RD-500 jet engine, which itself was based on a British Rolls-Royce Derwent 5 turbojet engine. The whole aerodynamic concept was taken from the older Yak-17, but improved with an all-metal construction. The new plane was a lightweight mid-wing monoplane, but with unswept wings and rear tail. The cockpit was placed at the middle of the fuselage and equipped with an ejection seat. To save weight, some modifications were done such as the omission of air brakes, the armor plate being removed, fuel tank capacity lowered, no pressurization fitted to the cockpit and decrease of the wing thickness. The calculated weight with these modifications was about 4,725 lbs (1,902 kg). By the time it entered production, there was a slight increase of weight. The main armament was also relatively light, as it consisted of only two 0.9 in (23 mm) cannons, with some 90 rounds for each cannon.
The work on this project began in the early 1947. Plant No.115 was tasked with the construction of the first operational prototype. On 17th June, 1947 the prototype, designated Yak-23-1 was completed. The first factory test flight was made on 8th July, 1947 by the test pilot M.I. Ivanov. The results of these first flights showed that the Yak-23-1 had a high rate of climb and excellent maneuverability. The maximum speed achieved was 578 mph (932 km/h) at low level. Some issues that were noted during these first flights were solved in time.
In September the same year, on the insistence of the Minister of Aircraft Production, Mikhail V. Khruniche, the Yak-23 was accepted for additional test trials. For this purpose, a second prototype was built, named Yak-23-2. For the series of new test flights, besides G.A.Sedov, the main test pilot, many more pilots were also chosen to test the Yak-23, such as A.G. Proshakov, Valentin, I. Khomvakov among others. By March 1948, these test flights were successfully completed. The Yak-23 displayed great maneuverability during flights. In contrast to other models, like Su-9 and MiG-9, the Yak-23 proved to have much better climb rate. But it was not without its problems: during acceleration, the forward fuselage tended to suddenly rise and the lack of air brakes made potential dog-fighting very difficult. At higher speeds it took a lot of time to slow down and the lack of a pressurized cockpit made the Yak-23 incapable of operating at high altitudes. The second prototype was lost on 14th July, 1948, during one of the many flight exercises for the planned military parade to be held at Tushino. During these exercises, an unknown object struck the wing of Yak-23-2 flown by M.I. Ivanov, which caused the wing to break and fall off. The pilot lost control and crashed to the ground. Ivanov died immediately and the aircraft was totally destroyed. A subsequent investigation found that the main culprit was a balance tab that was torn from the tail of one of the Tu-14 bombers that was flying above the Yak-23.
Despite these problems, the Yak-23 was considered a successful aircraft worthy of production. Plant No.31 was chosen for manufacturing. By mid-1949, the production began, however, at first, the process was slow due the lack of RD-500 engines. The first batch was not ready until October 1949. In the period of January to March 1950, some 20 aircraft were used to conduct more tests. These trials revealed that the Yak-23 had a few more problems to be worked out, such as smoke in the cockpit, among other small issues.. As these problems were considered minor and did not endanger the production of the Yak-23 at the time.
Design
The Yak-23 was designed as a lightweight, all-metal, mid-wing monoplane with unswept wings and tail surfaces. The long front fuselage was designed and constructed so that it could be easily changed or removed for ease of maintenance.
The external fuselage was made of 0.039 in (1 mm) thick duralumin sheets (D16AWTL) and the inner part was made of 0.031 in (0.8 mm) sheets. To protect the main landing wheels, a special cover was installed close to the exhaust nozzle. The lower part of the Yak-23 fuselage was covered with a specially designed heat resistant plate in order to protect the plane’s inner structure from any potential thermal damage. The two unswept wings were made of 17 ribs that were covered in 0.05-0.07 in (1.3-1.8 mm) duralumin panels. At the wing’s trailing edges, ailerons and flaps were fitted. The wings were made mostly of duralumin sheet metal. The wing ends were flat and it was possible to mount two external fuel tanks that were ejectable. The rear tail had a tapered design and was made of metal covered with duralumin sheets. There were no air brakes installed and this caused the Yak-23 to have some problems with maneuvering. This would be a major problem in any potential dogfight with other fighters.
The main engine was the RD-500 turbojet engine with 3,500 lbs (1590 kg) of thrust that was fitted with a single centrifugal compressor and nine cylindrical shaped combustion chambers. The engine had a diameter of 3.58 ft (1.09 m) and 6.76 ft (2.06 m) long. It was angled downwards by 4°30’ with respect to the plane’s centerline. This was not a perfect design choice as when the pilot accelerated the plane, it tended to suddenly pitch up. The main jet fuel was kerosene, stored in five large tanks mounted in the fuselage with a capacity of 240 gallons (910 liters) and two smaller 50 gallon (190 liters) tanks located in the wings. With this fuel capacity, the maximum operational range was around 640 mi (1,030 km). The Yak-23’s flight endurance was very low, with only one hour of operational flight. With this engine, the maximum speed achieved was 606 mph (975 km/h) with a climb rate of 6,693 ft (2,041 m) per minute. The air intake was located at the front, which split into two symmetrical ducts that passed under the cockpit. There was a headlight located in the air intake to help during landings.
The landing gear was a tricycle design typical of jet planes of the era. The front nose wheel retracted forward, while the larger rear wheels retracted into the fuselage sides. A built in shock absorber mechanism with double rebound system was used for the landing gear.
The cockpit was located at the center of the upper fuselage. The cockpit was designed with a fixed windscreen with an armored glass panel and a rear sliding hood with non-armored glass. For the pilot to enter his seat, he had to climb on top of the wings. The Yak-23 was equipped with an ejection seat that could be used by the pilot in case of emergency. The ejection seat with parachute was activated with a command handle located next to the armrest of the seat’s right side. A small explosive charge was used to catapult the seat from the plane. The main command instruments were in the standard configuration. All instruments were placed ahead of the pilot and the rudder pedals were mounted at the floor. The pilot’s instrument panel was divided into three sections. In the central section were the main and most important flying instruments: M-46 Mach meter, PDK-45 compass, AGK-47A artificial horizon, and engine control indicators. Secondary controls were located at sides of the main control panel. An oxygen supply system with a capacity of 2.11 gal (8 l) with a KM-16 model mask was fitted in the cockpit. Electric power was provided by 1.5 kW GSK-1500 generator and 12A-10 type battery. For communication, a RSI-6K radio set and a RPKO-10M radio-direction finder/semicompass were used. Also, the SCh-ZM IFF (Identification Friend or Foe) system was used.
The offensive weapon load consisted of only two 0.9 in (23 mm) NR-23 cannons placed in the lower forward part of the fuselage. Available ammunition for these two cannons was limited with only 90 rounds per gun. The main weapons were aimed by the semi-automatic gyro gun sight placed above the pilot’s instrument panels. Additional offensive armament could consist of two 123 lb (60 kg) bombs attached in the place of the external fuel tanks.
Beside the Yak-23 fighter aircraft, a trainer version, the Yak-23 UTI, was developed. One Yak-23 (serial number 115001) was converted for this purpose. A second instructor cockpit was installed at the rear of the pilot’s seat. The prototype was tested from March to September of 1949, but this modification was ultimately deemed unsuccessful. A new attempt was made with the redesigned Yak-23 UTI-II. The fuselage was stretched by some 7.8 inches (200 mm) to the front, and this time the instructor was moved to the front. A special periscope was installed to allow the instructor to see what the pilot was doing in the rear seat. The armament was reduced to only one 0.5 in (12.7 mm) machine gun. Many more changes were made, which resulted in the third version, Yak-23 UTI-III. By this time, the more impressive MiG-15 UTI was entering production and so the Yak-23 UTI project was canceled.
Operational use
Despite its good flying characteristics the Yak-23, also known by its NATO designation “Flora,” was built in small numbers, 310 planes in total. Its operational service life in the Soviet Union was very limited, as it was operated by only a few fighter regiments located in the Caucasus and Volga military districts. As more modern planes were becoming available, the Yak-23 would be sold off to Eastern bloc countries such as Czechoslovakia, Bulgaria, Romania and Poland.
In Czechoslovak Service
Czechoslovakia had extensively negotiated with Soviet military officials in the 1950s about the purchase of new jet-powered fighters. These negotiations had been preceded by earlier ones, from which Czechoslovakia received one older Yak-17 under designation S-100. This sole aircraft was to be used as a basis for future local production. However, since this plan went nowhere, the Yak-17 was sent to a military museum and it was never used operationally. An agreement was made in November 1950 for a possible license production of the Yak-23 under a new name, S-101, and also for the engine under the M-02 name. The first group of 12 Yak-23s arrived in Czechoslovakia in late 1950. Their first public appearance of nine planes were used in a military parade on 6th May, 1951, the anniversary of the liberation of Czechoslovakia by the Soviet Red Army in WW2. A second group of 9 Yak-23s was allegedly received, possibly in 1951 or 1952, but precise information is lacking.
The Yak’s were first used by the 3rd Fighter Division, but as the more advanced MiG-15 arrived, the Yak-23s were given to the 11th Fighter Regiment, part of the 5th Fighter Division, from June to August 1951. By early 1952, this unit had 11 operational Yak-23s in total. One Yak-23 was lost in an accident on 16 October, 1952. In 1953, all available Yaks were given to the 51st Air Regiment, which was renamed as the 7th Air Regiment in October. By early 1954, there were 12 Yak-23s reported in service, of which 11 were operational.
Due to the purchase of newer types of aircraft, the Czechoslovakian military authorities thought that the Yak-23 plane was inadequate and outdated and so the original plans for a license production were dropped. By 1956, a decision was made to withdraw all Yak-23s from operational service. Only a small number of Yak-23s where ever used by the Czech Air Force, thought to be around 21, but the exact number is unknown. Most of these were sold, 10 to Poland in 1953, possibly 7 to Bulgaria, with one given to a military museum and at least one was lost in an accident.
In Bulgarian Service
Bulgarian military officials purchased several Yak-17 UTI training variants and 12 Yak-23s from the Soviet Union in early 1951. These were used to form the 19th Fighter Regiment in March 1951. The first pilot to fly on one of the Yak-23s was Major Vasil Velichkov. On his first take-off, the engine suddenly stopped working and he was forced to land in a field near the airfield. Because it was necessary to train new pilots to fly the Yaks, some planes were supplied to the 2nd Training Combat Air Regiment, located at the Georgi Benkovski Flying School. In order to increase the number of units equipped with the Yak-23s, some 72 new planes were purchased from the Soviet Union in 1952. Around 7 Yak-23s were sold to Bulgaria by Czechoslovakia in early 1956. As in Czechoslovakia, the Yak-23 would not stay long in service, and by 1959 all were retired.
In Romanian Service
After the Second World War, the Romanian Military leadership had great plans for the revival of their shattered air force and acquiring modern jet planes. Some 60 Yak-23s were bought from the Soviet Union during the fifties, with the first 12 planes reaching Romania in early 1951. The total number of planes used is not known. As the more modern MiG-15 was received during 1953, the Yak-23 was considered obsolete and only small numbers were ever used. One Yak-23 was modified by the Romanian air engineers of the AEMV-2 (Atelierele de Reparații / Material Volant) to be used as a dual-command trainer aircraft. A new instructor cockpit was installed. This new modified plane was designated as Yak-23 DC (Dublă Comandă / double command), but only a single prototype was built.
On the 24th June, 1953, Romanian pilot Mihail Diaconu escaped to Yugoslavia in Yak-23, where he sought asylum. Not long afterwards, another pilot flying a MiG-15 flew over and later landed onto Yugoslav territory, most likely due to a navigation error. Both planes were thoroughly researched and tested. Pilots Todorović and Prebeg both flew the Yak-23 with more than 4 flight hours. Beside the flying performance, the weapon systems were also tested during 1954. According to the agreement between US and Yugoslav military officials (code name ‘Zeta’), the Yak-23 was disassembled and sent to the Wright-Patterson Air Force Base in order to test the progress of Soviet aviation technology. Test flights were conducted on 4th November and, by 25 November, it was ready to be sent back to Yugoslavia. The Yak-23 was disassembled, and loaded onto a C-124 and later flown to Pančevo airfield. The whole operation was a complete success as it remained a secret for nearly 40 years. After several months, this Yak-23 was returned to Romania, without the Soviets ever realizing where it was the whole time.
In Polish Service
After the Second World War, Poland was economically and militarily devastated. It took several years before the beginning of the renewal of Polish military power. The new Polish military leadership wanted to built up the shattered air force and, despite their plans to acquire a new jet fighter by 1948, this was not possible. The process of acquiring new jet fighters began only in the spring of 1950. The first negotiations with the Soviet Union focused on the acquisition of Yak-15s, but this was later changed to the Yak-17. Due to outbreak of the Korean war, Soviet authorities decided to supply their allies with larger numbers of newer jet fighters. On 6th January, 1951, Poland received its first Yak-23 planes. The planned production of the older Yak-17s was suspended in favor of the Yak-23 under the Polish designation G-3.
Besides the 1st Fighter Aviation Regiment (PLM for short in Polish) which had some 16 Yak-23, a second unit, the 2nd PLM was also supplied with this plane. To train the new pilots, Yak-17 UTI training planes were used. In mid-1952, all operational Yaks were used by five Fighter Regiments: 2nd PLM with 26, the 39th PLM with 19, the 40th PLM with 19, the 26th PLM with around 11 and the 29th PLM with 14 Yak-23. From 1953 onwards, according to the new Polish military strategy, the first line fighter units would be equipped with the new MiG-15, while second-line units received all available Yak-23s.
In the early fifties, the Western Allies were eager to examine and spy on the military power of the East. A simple way to do this was by using various types of balloons. They were used for propaganda, meteorological, and reconnaissance duties. The Polish Air Force was heavily engaged with shooting down these balloons.
The final fate of Polish Yak-23s was sealed by the start of licenced production of the MiG-15 (under the name Lim-1). The remaining Yak-23s were gradually phased out of service. All operational Yak planes were allocated to training units at Radom, where they were used for training new officers and pilots. Some Yak-23s were temporarily used as reconnaissance aircraft in the 21st PLZ (21st Scout Aviation Regiment). By late August 1954, all Yak-23s were moved to Radom. The ones that were not operational were cannibalized for spare parts. On 1st September, 1959, the remaining 39 Yak-23s were removed from the Polish Air Force and a few would be used as memorials. During its operational service in the Polish Air Force, several planes were lost in crashes but, in most cases, the pilots escaped without any injuries.
Albanian Yak-23
Albanian Air Force allegedly operated a unknown number of Yak-23. Possibly bought from Poland sometime after 1951, according to author Yefim G.
Hungary and the Yak-23
Hungary allegedly also used the Yak-17 and 23, but there is no documentation or any information to confirm this (Source Marian M.). But according to author Yefim G. an unknown number of Yak 23 were operated by the Hungarian Air Force during the 1955 to 1956. But this author does not specify the number of planes used nor describes in more detail operational service life.
Production and modifications
A relatively small number of planes of this type were ever produced. As more advanced planes were becoming rapidly available, there was no need to continue the production of the old Yak-23. Most of the Yak-23s produced would be later sold to Eastern bloc countries.
In total, 310 aircraft plus three prototypes were built by Plant No.31. The plant produced these in twelve series, with 25 to 26 aircraft in each batch. Production was stopped by the end of 1950.
Variants
Yak-23 – Main production aircraft
Yak-23 UTI – One Yak-23 was modified to be used as a fighter trainer. It did not enter production.
Yak-23 DC (Dublă Comandă) – Romanian experimental dual control trainer, only one tested.
Operators
Bulgaria – Used over 70 Yak-23s
Soviet Union – Operated only two fighter regiments equipped with the Yak-23
Romania – Some 60 Yak-23 were bought from the Soviet Union during the fifties
Poland – Used around 101 planes, under the designation G-3
Czechoslovakia – Operated around 21 aircraft (possibly more) under the designation S-101
Yugoslavia – Used one Romanian interned plane for experimenting with flying performance and weaponry
USA – Briefly tested one aircraft that was supplied by Yugoslavia
Hungary – Allegedly used this type of aircraft, but proof is lacking
Albania – Possibly operated a small numbers of Yak-23
Conclusion
The Yak-23, despite proving that it had good flying performance and good handling, had a rudimentary design and was produced too late to have any great impact or role in the Soviet fighter force. Due to the rapid development of jet technology, more advanced planes were soon ready for service like the La-15 or MiG-15. The Yak-23 finished its career in service with many Eastern Block air forces.
Although its operational service life was short and its significance was negligible, the Yak-23 was an example of how, with only a short time and using limited resources, a solid jet fighter could be designed and built by the Soviets.
Yakovlev Yak-23 Specifications
Wingspan
28 ft 7 in / 8.73 m
Length
26 ft 7.8 in / 8.12 m
Height
10 ft 10.3 in / 3,31 m
Wing Area
145.32 ft² / 13.5 m²
Engine
One Klimov 3,505 lbs/1,590 kg thrust RD-500 turbojet engine
Soviet Union / Russian Federation (1985) Fighter Plane – 1,946 Built
Russia might not be the Superpower it once was. But its recent assertiveness indicates that it is willing to return to the stage as a great power, aiming at asserting its own interests at is neighbouring areas. One of the tools to do so is air power, which and although diminished in contrast to its former Cold War scale, is still considerable. The Su-27 and its different variants in service with the Russian Air Force are among the spearhead elements pushing forwards Russia’s interests. And this is not surprising, considering that the Su-27 and its variants are among the most advanced and top-quality technology jet fighters any nation can possess. The Su-27 can be traced back to the same year the F-15 Eagle was under concept and development (1969). The Soviets realized that the features of the F-15 and its technological advancement would threaten Soviet air power, thus prompting the General Staff to issue the requirements for wasit would be the Soviet answer to the Eagle. The new fighter was purposed to be for a long-range fighter, with good short-field performance (or the ability to take off and land on short airstrips, as well as to use austere runways), remarkable manoeuvring and agility, capable of reaching speed up to Mach 2+ speed and capable of carrying heavy weaponry. The Su-27 was purposed, at the same time, at countering not only the Eagle but also the F-14 Tomcat, as well as to complement the Mig-29, as the latter’s role was as tactical superiority fighter, dealing with NATO fighters and strike aircraft. It would operate also as bomber escort. As the requirements proved to be very complex and costly, they were split into two different ones: one for a lightweight fighter (whose outcome was the abovementioned Mig-29), and another for a heavyweight fighter (whose outcome was the Sukhoi Su-29). This fact explains why both airframes are very similar. The first flight took place in 1977.
The Su-27 ‘Flanker’ (as it came to be denominated by NATO) is a very though rival of the F-15. This is possible thanks to the low wing loading and the basic flight power controls, which bestows the fighter agility and good control, even at low speeds and high angle of attack of 120°, at the point ofbeing capable of performing the famous Pugachev’s Cobra manoeuvre. The structure is very similar to that of the Mig-29, clearly being a product of having a parallel development and starting from a similar requirement, although being larger than that of the Mig. The wing is a swept wing cropped delta type, having the tips cropped for missile rails or ECM pods, and blending with the central fuselage at the leading-edge extensions. The horizontal tailplanes are also of delta configuration, taking part of the Su-27 tailed delta wing configuration. Being the first Soviet aircraft in incorporating a fly-by-wire technology, its exceptional characteristics in terms of agility and manoeuvrability are in part thanks to this technology. The engines provide the Su-27 high speed (2500 km/h; 1,550 mph), being slightly lesser than that of the F-15 Eagle; these engines are a couple of Saturn/Lyulka AL-31F turbofans with afterburners. They are installed in two separated pods, each harboring a tail. Hence, it has a twin tail configuration; this and the engine pods configuration make it to be similar to the F-14 Tomcat. This resemblance is reinforced by the fact that there is a space between the pods, increasing the lifting surface and hiding weaponry from the enemy radars.
The last element making the Su-27 an equal to the F-15 is the avionics installed on it. The radar is a Phazotron N001 Myech pulse-doppler radar with ‘track while scan’ and look-down/shoot-down capabilities, complemented by a OLS-27 infrared search and track at the nose, with a range of between 80-100 km. The armament of the Su-27 is no less important, comprised by a 30mm Gryazev-Shipunov Gsh-3101 located at the starboard wingroot, and up to 10 hardpoint with capability of carrying up to 6000kg (13227,73 Lbs), which includes up to six medium-range R-27 (AA-10 ‘Alamo’ in NATO code) and 2-4 short-range heat-seeking R-73 (AA-11 missiles ‘Archer’ in NATO code). Armament deployment tends to vary from version to version, being this the most “standard” configuration.
The Su 27 has proven to be a very good platform for further development, enhancing the characteristics of the basic model as new variants and subvariants are being introduced at the point of constituting new models by themselves. There is even a version which is a strike fighter/fighter-bomber capable of taking ground and naval targets.
One of the first versions that followed is the Su-30 family, known as ‘Flanker-C’ by NATO and based on the Su-27UB training version. This version has enhanced range, thrust vectoring which in turn enhances manoeuvrability while having the same powerplant of the basic model. The avionics are enhanced as well, having an autopilot for all flight stages and low altitude flight in terrain-following radar mode, individual and group combat capabilities against air and ground/sea-surface targets. The automatic control systems interconnected with navigation systems allows automatic mode for route flight, target approach, recovery to airfield and landing approach.
The version that follows is the Su-33, which is the naval version of the Su-27 and is often denominated as Su-27K (‘Flanker-D’), operated by the Russian Navy from the sole carrier it has (the Admiral Kuznetsov). Developed since the Soviet era, it became the first conventional airplane (along with its test pilot, Viktor Pugachev) in landing in the deck of a carrier in November 1989. It was purposed with replacing the less capable Yakovlev Yak-38 and to operate from the projected aircraft carriers, thus requiring the needed structural modifications: reinforced structure and undercarriage, enlargement of leading edge slats, flaperons and similar surfaces, canards, modified rear radome, folding wings and new powerplants (2 x Saturn/Lyulka AL-31F3 with slightly increased thrust). The Su-33 symbolized the Soviet efforts of creating its own fleet of aircraft carriers, which was not materialized as the End of the Cold War took place, as well as to have their own naval-based air power to enhance strategic projection. 1996 marked the year when the Su-33 became fully operational with interception missions, although having limited ground-attack capabilities. Thedetected limits and issues with the combination fighter-warships , and the budget cuts limited the naval operation of this version, yet air-to-air refuelling and real-life fire trainings have taken place. A two-seat version (SU-27KUB) might emerge any time.
The next version is the Su-32/34, which is the abovementioned strike fighter/fighter-bomber, purposed at replacing the Su-24. Equally based on the Su-27 airframe, its mission is to deal at tactical level with ground and naval targets, more specifically tactical bombing, attack, reconnaissance and/or interdiction. It can operate alone or in groups, under any weather condition and under any environment saturated with AA defences and EW countermeasures. It features canards, a new nose and a side-by-side-seating allowing two pilots, new powerplants (Saturn Lyulka AL-31FM turbofan engines), and a range of 4000 km (2,500 mi). The cockpit provides ample space for the crew to rest, being also pressurized and having at its rear a galley and a toilet. Its electronics – a Helmet Mounted Display System, Khibiny Electronic countermeasures, and a very ample and capable radar complemented by a second radar at the rear – allows the Su-32/34 to scan an area of 200-250 km, to attack four targets either at sea, air or land, and even to be warned against attackers behind and engage them without turning. This version has seen extensive action in Syria.
The version that followed is the Su-35 (‘Flanker-E), an all-weather air superiority and supermanoeuvrable multirole fighter, featuring a structure composed of high-strength composites and Aluminium-lithium alloys, increasing fuel volume while reducing weight. The tail fins are larger, having carbon-fiber-reinforced polymer square-topped tips. Canards were removed while the powerplant was new, two Saturn/Lyulka AL-31FM turbofan engines, which is larger and with more thrust. This version also has new avionics, such as the fire-control system and the N011 Pulse-Doppler radar that allows the fighter to track up to 15 airborne targets and guide six missiles at the same time. The rear radar – a Phazotron N-012 – also complements the fire-control system. LCD screens are also a feature, while the seat is inclined with a 30° angle to allow the pilot to tolerate more -g forces. It can carry a new array of weapons, like napalm; dumb bombs (free-fall iron bombs) and cluster ammunition; air-to air and air-to-surface missiles, with the payload being increased as two new underwing pylons are installed. It has air-to-air refuelling capabilities, increasing operational range (4000 km / 2,222 mi). Only 58 units are in service with the Russian Air Force.
The Su-37 (‘Flanker-F’ and ‘Terminator’) is the most recent version, based on the Su-35, being a single-seat supermanoeuvrable multirole jet fighter, with upgrades such as avionic suite, fire-control systems and thrust vectoring noozles. It also features canards, and improved fire-control systems, with an upgraded N-011M BARS passive scanned array radar, tracking 15 airborne targets and guiding 4 missiles at the same time, complemented by a N-012 rearward facing radar, having also updated electronic warfare support measures, and 12 hardpoints allowing air-to-air and/or air-to-surface missiles. Moreover, the cockpit has 4 LCD multi-function displays, providing air data/navigation, system status, weapons/systems selection and tactical situation information. HUD, an ejection seat with 30° angle of inclination, and a steering with a side-stick and pressure-sensing throttles help the pilot in controlling and navigating the aircraft. This version, however, remained as a technology demonstrator, with a single unit being the only sample of this model.
Russia is not the only country producing the Sukhoi-27, as China, given the airframes that received 8or the technology and license to build them) has developed its own version of the Su-27. The first one is the Shenyang J-11 (NATO code Flanker-B+), which is based on the Su-27SK, in operation with the Chinese People’s Liberation Army Air Force (PLAAF). This version is fitted with Chinese-made improvements to the airframe and avionics (such as radars and avionics suites), as well as weaponry (such as the PL-12 medium-range active radar homing air-to-air missile, and anti-ship missiles). The powerplant was reported to be in principle a Chinese Shenyang WS-10 Taihan (based on the CFM56), yet it seems there is the aim of upgrading the J-11 fleet with either Saturn-117S or Salyut AL-31F-M1.
The second one, being a variant of the Chinese J-11, is the Shenyang J-15 Flying Shark. This version is purposed for aircraft carrier service and equally based on the Su-27K/Su-33, thanks to an unfinished prototype China acquired from, Ukraine. And just like the J-11, is equipped with Chinese avionics, powerplants and weaponry. Since its introduction in 2013, the J-15 has been operating from China’s sole carrier Liaoning, mainly on testing and taking-off/landing drills. This would be the main Chinese carrier-based air defence and attack asset when the carrier – and additional expected units – enter in service with the Chinese People’s Liberation Army Navy (PLAN).
The last Chinese-made version of the Su-27 is the Shenyang J-16, which is a strike fighter and multi-role fighter/bomber based on the J-11B and the Su-30MKK units sold to China by Russia. Of course, this version is equipped with Chinese avionics and powerplants, as well as weaponry, which includes: super and subsonic anti-ship missiles, satellite guided bombs, cruise missiles and ECM jammers. There is even an electronic warfare variant that lacks Infra-red search and track and the 30mm gun.
The Su-27 has seen action after 1985, year in which was introduced in the Soviet Air Force and after entering officially in service in 1990. The first operational even took place in 187, when a Su-27 intercepted a Norwegian P-3 Orion maritime patrol aircraft over the Barents Sea, colliding with it after executing some close passes. During the 1992-1993 Abkhazia War, Russian Su-27 operated against the Georgian forces, with a Su-27 lost due to friendly fire as it was intercepting a Georgian Su-25 on CAS mission. The Su-27s were used again over the skies of Georgia, this time during the 2008 South Ossetia War to gain air superiority over the scenario at Tskhinvali. It is rumoured that the Su-34 also took part during this conflict. Su-34 were also used to bomb ice dams in Vologda Oblast to prevent floods. In 2013, a couple of Su-27 were intercepted by four Japanese Mitsubishi F-2 after entering briefly Japanese air space and flying near Rishiri Island and the Sea of Japan before turning back. Another Su-27 was close to collide with a USAF Boeing RC-135. The S-35 is also in use by the Swift and Russian Knights acrobatic teams. The sole S-37 has been used for flight tests, demonstrations and air shows presentations.
Su-27 in use by other nations have seen some action too. In Ethiopia, during its war against Eritrea, the Ethiopian Sukhois reportedly shot down 4 Eritrean Mig-29 and damaging one; being tasked also with combat air patrols, escort, AA suppression, and even bombing Islamists garrisons. In Angola, one Su-27 was reportedly shot down by a SA-14 man-portable air defence missile system during the civil war. Indonesian Su-27s, meanwhile, were used on exercises with Australia, the US and other countries of the region, as four units took part in such. The most recent action of the Su-27 has been in Ukraine, during the conflict that is currently taking place there, with Ukrainian units tasked with air defence, combat air patrols and escort/interception of civilian flights flying over Eastern Ukraine.
The scenario where the Su-27 have seen some action is in Syria, with a squadron of Su-27M3 deploying as part of the Russian air campaign at this country. Some Russian Air Force Su-30SM have been deployed as well for the same campaign, performing escort and target illumination. The naval version (Su-24K/Su-33) saw very limited action during the 90’s, with those on-board the Admiral Kuznetsov carrier taking part in Russia’s air campaign over Syria as well, alongside the Su-34, which in turn executed precision strikes against both rebel and ISIS targets, forced to fly armed with missiles after a Su-24 was shot down by Turkey. Four Su-35S also took part in the operation.
The Chinese fighters have seen also limited action, mainly for interception of US reconnaissance and patrol aircraft, and tests and drills for take-off and landing on carrier decks (for the Chinese naval version).
The Su-27 and its variants were considerably produced, reaching a number of 809 (Su-27); near 540 (Su-30), with 18 (SU-30MKM), 134 (SU-30MKK/MK2) and 225 (SU-30MKI); 35 (Su-27K/Su-33); 107 (Su-32/34); 15 (Su-27M); 58 (SU-35S) and 4 (Su-35 for China); 1 (Su-37); 235 (J-11); 20 (J-15); and 624 (J-16). Russia (and Sukhoi) are not the only producers, as Irkut Corporation, Komsomolsk-on-Amur Aircraft Production Association (KnAAPO), Shenyang, and Hindustan Aeronautics Limited, all produce the Su-27 and its different variants, including those manufactured abroad Russia with license or being copies of airframe, like the Chinese case. A considerable number of nations are users of the Su-27 and either version, making this aircraft a strong competitor in the international defence industry. In Russia, the Su-27 will be replaced by the 5th generation fighter Sukhoi PAK FA.
Design
The Su-27 airframe is similar to that of the Mig-29, only that its size is larger. In fact, the fuselage has a very characteristic shape at the longitudinal view, with more than half of the forward section being ‘above’ the wing, harbouring the nosecone, the cockpit and canopy, as well as the airbrake (placed behind the cockpit). This one is located at the same area of the wing-edge extensions. This forward area is having a hunchback shape, which gives a great advantage for the pilot, as the height provides a good view, alongside the bubble shape of the canopy. There, a K-63DM series two ejection seat (with an inclination of 17°) is installed, alongside analogue instruments, HUD and head down display data from the radar and the IRST, as well as sensors for the helmet-mounted target designation system and indicators. At the very frontal part of the canopy, there is a small radome or protuberance, where IRST device is installed. Interestingly, the inferior section of this area is not straight; in fact, it has a slight inclination forward. The rear part of the main fuselage is where the engine nacelles, nozzles, air intakes and the vertical stabilizers are located. The landing gear is of tricycle configuration, with the rear wings being retractable to the wing section, and the forward gear being placed below the rear area of the canopy, having a mudguard for protection against foreign object damage (FOD).
The wing is a swept trapezoidal wing that is also cropped, with the purpose of allowing missile rails or ECM pods at the wingtips. The horizontal stabilizers are also of a delta shape, which along the main wings makes of the Su-27 to look like a tailed delta wing configuration. Noteworthy to point out that the main wing merges into the fuselage at the leading-edge extensions (these extensions are slightly curved thus giving the Su-27 its characteristic shape). These wings and configuration in fact bestows the fighter with great manoeuvrability and great control, as it can fly at very low speeds and with an angle of attack of 120°, which result in the Su-27 to be capable of performing the Pugachev’s Cobra and dynamic deceleration. Some versions have their flight controls and manoeuvrability enhanced by the addition of canards located at the leading-edge extensions, as well the lift – which is increased – and a reduction of distances required for takeoff; the Su-27K/Su-33, some versions of the Su-30, the Su-35 and the Su-37 are fitted with those canards. The wings are not the only secret behind the Su-27 performance, for the incorporated fly-by-wire technology also plays its part on yielding the manoeuvrability this fighter has. These characteristics come at hand for the Su-27 in case of dogfighting. The Su-27 is also fitted with twin tales located aft the airframe, over the engine nacelles. They are complemented by small winglets installed immediately below. The engine noozles are ‘extended’ beyond the location of the twin tail, yet located between the horizontal stabilizers. Between the noozles, there is a radome aft the fuselage, acting as a rear prolongation of the airframe and hosting a rear-side radar.
The avionics make of the Su-27 and its versions a formidable opponent, as it is fitted with a Phazotron N001 Myech coherent pulse-Doppler radar, having track while scan and look-down/shoot-down capability, thus making the Su-27 capable of having a lock on its targets. This radar has a range of 80-100 km in horizontal, and of 30-40 km at the rear hemisphere. It is capable of tracking 10 targets and prioritize the target to be intercepted. There is also a SUV-27 fire control system fitted with a RLPK-27 radar sighting system, a OEPS-27 electro-optical system, a SEI-31 integrated indication system, an IFF device/interrogator and a built-in test system. The SUV-27 fire control system is integrated with a PNK-10 flight navigation system, a radio command link, the IFF device, the data transmission, the data transmission equipment and the EW self-defence system. The OEPS-27 is composed of the OLS-27 IRST and the helmet-mount sight that allows lock by look, controlled by the Ts-100 digital (central) computer. In addition, the SEI-31 integrated indication system provides navigation, flight and sight data to the HUD. These avionics, in fact, enables the SU-27 to engage targets beyond the visual range, bestowing a long punch thus making it a serious contender in aerial combat.
These capacities (especially the manoeuvrability, but also the fire power) are somehow complemented by the powerplant, which bestows the fighter in tandem with the aerodynamics and the wing design, its characteristics, yielding also very good combat capabilities. The powerplant consists of a couple of Saturn/Lyulka AL-31F bypass engines with a thrust of 12500 kg (each), yielding a maximum speed of 2500 km/h (1,550 mph). Two engine intakes variable ramps allow the engines to receive the air, while the specific shape allows optimal performance at any given speed and altitude.
The armament tends to vary according to the different versions. The most common one is the 30mm GSh cannon, located at the starboard wingroot. The additional advantage the wings have is that they allow the Su-27 to carry large numbers of weapons and other equipment, as it hosts up to 10 hardpoints. The combination of R-73 (AA-11 ‘Archer’) and R-27 (AA—10 ‘Alamo’) is the most common, but there are various schemes of weaponry according to the different versions and models of the Su-27.
On The Road to Damascus
Russia has waged an extensive air campaign over Syria in order to support the Assad government, which is a very close – in fact, strategic – ally of Russia. This support is aimed at keeping Assad in the power, so Russia can have a platform from which to strengthen its presence in the Middle East, as the civil war unfolds. Given this context, the Sukhoi Su-27 is one of the main tools used by Russia to wage this campaign, making use of both land and sea-based assets, and of varied versions. It is also reported that the deployment of the air assets could help in boost the Russian share in the security and defence markets, by demonstrating the capabilities of the Su-27 in real-time combat. The most prolific ones deployed so far is the Su-27SM3, the Su-30SM and the Su-35S, along with other air assets (like the Su-24 ‘Fencer’). As the air campaign began in September the 30th 2015, with the objectives being ISIS terrorist personnel, facilities, camps, vehicles and facilities, although it has been reported that Russian air strikes have targeted the rebel groups instead of ISIS.
In any case, the role of the ‘Flankers’ has been very important, but some have paid a price. The first assets deployed were the Su-27SM 3 and the Su-30 SM, tasked mainly with air protection and escort the fighter/bombers and strike aircraft Su-24 ‘Fencer’ and Su-25 ‘Frogfoot’, as well as providing escort to bombers. Furthermore, the early deployed Flankers were providing target illumination to the bombers launching airstrikes against their designated targets. After an Su-24 was shot down by Turkey in 2015, Russia decided to deploy the Su-35S, to enhance air superiority and control over the area of operations, along with advanced AA defence systems (such as the S-400) and arming the deployed fighters with live-round missiles.
Another deployed version of the Su-27 is the Su-34, with 14 units carrying precision strikes and having no air escort whatsoever, for they have considerable air-defence capabilities. Noteworthy to point out that Russian air assets are deployed mainly at Latakia and Khmeimim air bases, as well as at the airport in Damascus.
The Navy-operated Sukhois have seen some action over the skies of Syria as well, as they have taken part in combat flights from the deck of the Russian carrier Admiral Kuznetsov. These airplanes too have suffered a series of incidents. On December the 3rd 2016, a Su-33 failed to land after a first equally failed attempt, as the arresting cable snapped thus not stopping the aircraft, which went overboard. This incident prompted the Russian Navy to move all the carrier’s air assets to the Syrian Hmeymim air base, while the problems with the arresting cables are solved.
Variants
T-10 (‘Flanker-A’) – The first prototype of the Flanker
T-10S – The improved version of the T-10 prototype.
P-42 – A version quite similar to the US F-15 Streak Eagle project, it was purposed with beating climb time records, lacking radar, armament and even painting for that.
Su-27 – The pre-production series built in small quantities and fitted with the Lyulka AL-31 turbofan engines.
Su-27 S (Su-27/ ‘Flanker B’), or T10P – The initial production series version with one seat, equipped with the improved version of the Lyulka turbofan engines, the AL-31F.
Su-27 P (Su-27/ ‘Flanker B’) – The standard version yet lacking air-to-ground weapons control system and wiring. These units, denominated as Su-27, were assigned to the Soviet Air Defence Forces, an independent branch from the Soviet Air Force.
Su-27 UB (‘Flanker C’) – The initial production of a two-seat operational trainer.
Su-27SK – The single-seat export version of the Su-27S, delivered to China in the mid 90’s. The Shenyang J-11 was developed from this particular version.
Su-27UBK – The export version of the Su-27UB two-seat version.
Su-27K (Su-33 / ‘Flanker D’) – A carrier single-seat capable version featuring folding wings, high-lift devices and a tailhook arresting gear for carrier operations. Near 30 were produced.
Su-27M (Su-35/Su-37 ‘Flanker E/F’) – Improved demonstrators for an advanced multi-role single-seat fighter derived from the Su-27S, which included also a two-seated Su-27UB.
Su-27PU (Su-30) – The two-seat version of the Su-27, with the purpose of supporting with tactical data other single-seat Su-27P, Mig-31 and other interceptors in service with the Soviet Air Defence Forces. This version resulted in the Su-30, which came to be a multi-role fighter for export.
Su-32 (Su-27IB) – A long-range strike version with a side-by-side seating having a platypus-type nose, it was also the prototype of the Su-32FN and the Su-34 ‘Fullback’.
Su-27PD – A single seat demonstrator featuring several improvements, including an inflight refuelling probe.
Su-30, Su-30M / Su-30MK – A next-generation two-seat multi-role fighter. Some units were used for evaluation in Russia, with 88 units (Su-30, Su-30M2 and Su-30SM) in service with both the Russian Air Force and the Naval Aviation. The Su-30MK became a couple of demonstrators to secure exports, deriving in the Su-30MKA, Su-30MKI, Su-30MKK and Su-30MKM. In detail, the Su-30 has the following (export) versions:
Su-30K – Basic export version of the Su-30.
Su-30KI – Proposed upgrade for the Su-27S. it was also a proposed export version for Indonesia, with an order for 24 aborted due to the 1997 Asian Financial Crisis.
Su-30KN – An upgrade project for two-seat fighters; such as the Su-27UB, the Su-30 and Su-30UBK. Revived as the Su-30M2 after it was briefly cancelled. Belarus was also considering updating former Indian Su-30K to the Su-30KN.
Su-30MK – Commercial version of the Su-30M, fitted with navigation and communication equipment made by Hindustan Aeronautics Limited.
Su-30M2 – A KnAAPO version based on the Su-30MK2. Around 24 airframes were delivered to the Russian Air Force, and used for combat training aircraft for Su-27SM fighters.
Su-30MKI – A version developed in cooperation with India’s Hindustan Aeronautics Limited for the Indian Air Force (hence the acronym ‘MKI’, which stands for “Modernizirovanny, Kommercheskiy, Indiski”, or “Modernized, Commercial, Indian”). It features thrusts vectoring controls and canards. A remarkable feature is that it is equipped with a mixture of avionics with components made in Russia, India, France and Israel.
Su-30MKK – A version for export to China (“Modernizirovanny, Kommercheskiy, Kitayiski” / “Modernized, Commercial, China”).
Su-30MKM – Developed from the Su-30MKI, it’s a dedicated version for the royal Malaysian Air Force, and like the Su-30MKI, it features thrust vectoring controls and canards as well as avionics from various nations. The HUD, the navigational forward-looking infra-red system and the Damocles laser designation pod are made in France (Thales group of France). The MAW-300 missile approach warning system, the RWS-50 RWR and laser warning sensor are made in South Africa (SAAB AVITRONICS). And the NIIP N011M Bars Passive electronically scanner array radar, the EW system, the optical-location System and the glass cockpit are made by Russia.
Su-30MKA – Another version developed from the Su-30MKI for Algeria, featuring a mixture of Russian and French-made avionics.
Su-30SM and SME – A version for the Russian Air Force, being based on the Su-30MKI (and even MKM), and considered a 4+ generation fighter. This version is built upon Russian requirements for radar, radio communication systems, friend-or-foe identification system, ejection seats, and weapons, among others. The Bars-R radar and a wide-angle HUD are among the features of this version. The export version was unveiled at the Singapore Air Show 2016, denominated SU-30SME.
Su-30MKV – Export version for Venezuela.
Su-30MK2V – A variant for Vietnam, having little modifications.
Su-27SM (‘Flanker-B’ Mod. 1) – The mid-life upgraded version of the Su-27S, having incorporated the technology fitted in the Su-27M.
Su-27SKM – A single-seat multi-role fighter for export, developed from the Su-27SK yet fitted with an advanced cockpit, more-sophisticated self-defence ECM and in-flight refuelling system.
Su-27UBM – An upgraded Su-27UB.
Su-27SM2 – An upgrade of the Su-27 into a 4+ generation fighter, featuring an Irbis-E radar, upgraded avionics and engines.
Su-27SM3 – Similar to the Su-27SM, only that it is a new airframe instead of an updated one.
Su-27KUB – A Su-27K carrier version which is a two-seat side-by-side version that is used as carrier version or multi-role aircraft.
Su-35 – The most recent developed version of the Su-27, it has upgraded avionics and radar, powered by a thrust vectoring Saturn AL-41F1S engine. It has the following variants:
Su-27M/Su-35 – A single-seat fighter.
Su-35UB – A two-seat trainer, featuring taller vertical stabilizers (or tails), with the forward fuselage being similar to that of the Su-30.
Su-35BM – A single-seat fighter having enhanced avionics and some modifications to the airframe. The denomination “Su-35BM” is an informal one.
Su-37 – A thrust-vectoring demonstrator.Su-35S – A version for the Russian Air Force of the Su-35BM.
Su-27UB1M – The Ukrainian modernized version of the Su-27UB.
Su-27UP1M – The Ukrainian modernized version of the Su-27UP.
Su-27S1M – The Ukrainian modernized version of the Su-27S.
Su-27P1M – The Ukrainian version of the Su-27P.
Shengyang J-11, J-15 and J-16 – The Chinese versions of the Su-27(SK). These versions have also their own sub-variants as it follows:
J-11A – Units assembled by both China and Russia, as the parts were provided by Russia with China assembling them. They were latter upgraded with Missile Approach Warning (MAWS), and reportedly new cockpit displays and fire control for R-77 (AA-12 ‘Adder’) or PL-10. 104 built/assembled.
J-11B – Produced in China with Chinese technology, it is powered by the Shenyang WS-10A turbofan and being also slightly lighter thanks to the use of composite materials. It features new avionics, glass cockpit, MAWS, and onboard oxygen generation system. It might receive an Active electronically scanned array radar.
J-11BS – The twin-seat version of the J-11
J-11BH – Naval version of the J-11
J-11BSH – Naval version of the J-11BS
J-15 – Carrier-based version featuring some structural elements from the acquired Su-33 prototype, as well as avionics of the J-11B
J-16 and J-16D – Strike variant and EW variant, respectively. The latter has the wingtip pods resembling the AN/ALQ-218, with the wings and fuselage allowing up to 10 hardpoints yet lacking IRST of the Gsh 30mm cannon.
J-11D – Version featuring an electronically scanned array radar, IRST, and capacity to fire heavier imagine/infrared (IRR) air-to-air missiles. Many composite materials are part of the structure, with the engine intakes being the most remarkable one, as it is aimed at reducing radar visibility. It is supposed that new fly-by-wire control system, glass cockpit, improved electronic warfare systems and an enhanced version of the WS-10A engine are fitted in the plane.
Operators
Soviet Union/Russia Russia is among the main users of the Su-27 and variants, in service with both the Air Force and the Navy, starting its career with the Soviet Air Force and soviet Air Defence Forces. By January 2014, the Russian Air Force was reportedly operating 359 Su-27, of which 225 were of the basic Su-27 model, 70 Su-27MS, 12 Su-27MS3 and 52 Su-27UB. All of these airframes were to be subjected to modernization, with half of them being upgraded to the Su-27MS3. The Russian air force also operates with 3 Su-30, 20 Su-27M2 and 66 Su-30SM. 28 additional Su-30SM are expected as they are in order. 8 were issued to the Russian aerobatic team Russian Knights. 103 units of the Su-32/34 versions are operated by the Russian Air Force. 58 Su-35S are also part of the inventory.
The Russian Navy (Naval Aviation branch), in turn, was operating 53 Su-27 by January 2014, operating also 15 Su-30SM, being part of an order for 28 of such airframes, with 50 planned.
United States The US operates with two SU-27 airframes purchased from Belarus in 1995, with two additional former Ukrainian airframes purchased by Pride Aircraft. The US/private owned airframes are used for combat training for US pilots, with strong emphasis on dissimilar air combat training.
Ukraine The Ukrainian Air Force is having between 50-70 airframes, of which 16 were operational by 2015. They have seen operational action due to the conflict currently taking place at Eastern Ukraine.
Belarus After the USSR collapsed, Belarus received almost 30 Su-27. Two or three were sold to Angola in 1998, with the remaining 17 Su-27P and 4 Su-27UBM being retired in 2012
People’s Republic of China The People’s Republic of China is the second main operator of the Su-27, being also the first nation to which the Su-27 was exported by the early 90’s. The Chinese PLAAF was operating 33 Su-27SK and 26 Su-27UBK by January 2013. As China was allowed to produce its own airframes under license, the Shenyang J-11 (95 J-11A and 110 J-11B and J-11BS by the airforce; 48 J-11B and J-11BS by the Naval Aviation), J-15 (around 20 operated by the Navy Air Force) and J-16 (24 units apparently built) came to be the Chinese versions of the Su-27. The PLAAF and the Naval Aviation of China also operates 76 Su-30MKK and 24 Su-30MK2 respectively. 24 Su-35 were ordered, with 4 units received.
India The Indian Air Force operates 254 Su-30MKI, with the first units manufactured in Russia, and the following units assembles in India and under license by Hindustan Aeronautics Limited. It is the third main user of the Su-27.
Indonesia The Indonesian Air Force was operating 5 Su-27SK/SKM fighters by 2013. It also operates 18 Su-30MKM/MK2.
Vietnam The Vietnamese Air Force (Vietnam People’s Air Force was operating 9 Su-27SK and 3 Su-27UBK by 2013, along with 4 Su-30MK and 20 Su-30 MK2V. 12 more Su-30MK2V were received between 2014-2015, making a total of 32 Su-30MK2V.
Malaysia The Royal Malaysian Air force operates 18 Su-30MKM. A curious fact of the purchasing agreement was for Russia to send the first Malayan cosmonaut to the International Space Station.
Mongolia The Air Force of Mongolia operates 4 Su-27, with 8 more to be delivered.
Kazakhstan By 2010 it was operating 30 Su-27, having 12 in order. Reportedly, it operates 6 Su-30SM.
Uzbekistan 34 Su-27 were reportedly operated by this nation in 2013.
Algeria 44 Su-30MKA are part of the Algerian Air Force inventory, with 14 more airframes ordered.
Eritrea 8 Su-27SK/UB were received in 2003, with 9 being on service by 2013.
Ethiopia In 2013, this nation was operating 12 Su-27, 8 of which were Su-27SK.
Angola The Western African nation received 8 Su-27, 3 from Belarus. One was reported as shot down by a MANPADS in 2000 during the Civil War. 7 units were in service by 2013. Presumably, 18 Su-30K were ordered.
Uganda The Ugandan Air Force operates 6 Su-30MK2.
Venezuela The Venezuelan Air Force operates 24 Su-30MK2, with 12 more being considered for purchase. One was lost during a drug interdiction mission as it crashed.
Specifications (Su-27SK)
Wingspan
14,7 m / 48 ft 3 in
Length
21,9 m / 72 ft
Height
5,92 m / 19 ft 6 in
Wing Area
62 m² / 667 ft²
Engine
2 X Saturn/Lyulka AL-31F afterburning turbofans
Maximum Take-Off Weight
30450 Kg / 67,100 lb
Empty Weight
16380 kg / 36,100 lb
Loaded Weight
23450 kg / 51,650 lb (with 56% of internal fuel)
G-limit
9
Climb Rate
59,000 ft/min (300 m/s)
Maximum Speed
At high altitude: Mach 2,35 (2500 km/h / 1,550+ mph), At low altitude: 1400 km/h / 870 mph)
Range
6530 Km / 2,193 miles at high altitude; 1340 Km / 800 miles at low altitude
Maximum Service Ceiling
19000 m /62,523 ft
Crew
1 (pilot)
Armament
1 X 30mm Gsh-301 autocannon.
10 harpoints allowing up to 6000 kg/ 13227.73 lbs: 6 X R-27 medium-range air-to-air missiles; 2 X R-73 short-range heat-seeking air-to-air missiles. Other versions can carry a large array of weaponry, such as: (Su-30 and Su-33) R-27ER (AA-10C) and R-27ET, R-73E and R-77 RVV-AE AA missiles; Kh-31P/A, Kh-29T/L, Kh-59ME, Kh-35, and Kh-59MT and MK; rockets; bombs (KAB 500KR, KAB 1500KR, FAB 500T, OFAB 250-270 and nuclear bombs); and ECM pods. (Su-34) R-27, R-73, R-77 AA missiles; Kh-29L/T, Kh-38, Kh-25MT/ML/MP, Kh-59, Kh-58, Kh-31, Kh-35, P-800 Oniks and Kh-65SE or Kh-SD air-to-ground, anti-radar, anti-ship and cruise missiles; bombs and tactical nuclear bombs; and additional fuel tanks; and EW and reconnaissance pods. (Su-35) laser-guided and unguided rockets; R-73E/M, R-74M, R-27R/ET/ER/T, R-77 and R-37 AA missiles; Kh-29T/L, Kh-31P/A and Kh-59M/E air-to-surface and cruise missiles; bombs; and a buddy refuelling pod.
The Chinese versions (J-11, J-15 and J-16) carry the Chinese-made PL-12, PL-9 and PL-8 AA missiles, as well as the Russian-made R-77, R-27 and R-73 AA missiles; unguided rockets and free-fall cluster bombs, satellite-guided bombs and laser-guided bombs; ECM pods; and anti-ship and anti-radar missiles.
Avionics
Among the avionics of the Su-27, there is a Phazotron N001 Myech coherent pulse-Doppler radar, with track while scan and look-down/shoot-down capability and a range of 80-100 km in horizontal, and of 30-40 at the rear hemisphere, capable of tracking 10 targets and prioritize the target to be intercepted. There is also a SUV-27 fire control system fitted with a RLPK-27 radar sighting system, a OEPS-27 electro-optical system, a SEI-31 integrated indication system, an IFF device/interrogator and a built-in test system. A PNK-10 flight navigation system, a radio command link, the IFF device, the data transmission, the data transmission equipment and EW self-defence system are also part of the avionics. OLS-27 IRST and the helmet-mount sight, a Ts-100 digital (central) computer, a SEI-31 integrated indication system and HUD are also among the standard avionics fitted in the Su-37.