The Soviet Union produced a staggering array of combat aircraft in the decades following the conclusion of the Second World War, but Russian aircraft design innovation started to lag in the 1960s. Soviet second and third-generation fighter designs were judged as capable, but lacking in sophistication compared to their Western counterparts. All this changed in the 1970s when the Soviet Union produced several aircraft projects that were easily the equal of new 4th generation Western fighters, and one of the best of these was the Sukhoi Su-27 ‘Flanker’.
The Flanker badly shocked Western observers with its agility and sophistication, and the Su-27 was to spawn a series of improved derivatives for both naval and air force use, These models increased in both refinement and ability with each new service entry.
As these new variants entered service with Russia and her allies, the Flanker family allowed those services who operated her to confront potential adversaries with a world-class heavy fighter that possessed impressive strike capabilities as well. Even with the introduction of stealth aircraft into general service, the latest models of the Flanker remain respected to this day as lethal and enormously capable air-to-air/ground platforms.
Genesis and Later Development
The introduction of the 4th generation ‘teen’ series of fighters into Western inventories largely reduced most of the Soviet fighter force to increasing obsolescence as the 1970s progressed.
Soviet general staff recognised this problem and initiated a program to introduce new air combat capabilities for the 1980s, and in an eerie similarity to American conceptual thinking the proposal of ‘heavy’ and ‘light’ designs for manufacture was approved. The ‘light’ blueprint eventuated as the MiG-29 ‘Fulcrum’, and the ‘heavy’ design resulted in the adoption of the Su-27 ‘Flanker’.
The requirements for the proposed aircraft were extremely ambitious: Mach 2+ speed, high manoeuvrability, very long range, heavy ordnance capacity and the ability to operate from austere airfields.
While not all of these demands were satisfied, the resulting design showcased a large, handsome fighter with an emphasis on air-to-air combat prowess, but with an ability to attack surface targets. Sukhoi was authorised to manufacture a prototype, and the T-10 first flew in May 1977.
Suhkoi’s new aircraft had a troubled genesis, with several of the prototypes crashing causing pilot fatalities, but the design finally entered service as the Su-27 (NATO reporting name Flanker ‘B’).
The type started entering service with the Soviet air force in 1985 but was not in general service until nearly 1990. The Flanker served in front-line units as an interceptor, and it was envisaged that the type would perform well as a long-range bomber escort, accompanying such aircraft as the TU-22M ‘Backfire’ and the TU-160 ‘Blackjack’.
The Su-27 basic design was used as a template for single-seat and twin-seat derivatives, intended for both naval and air force use. Twin-seat versions were produced as trainers, and as export models to other nations, and along with single-seaters were adopted for use as naval fighters, long-range strike aircraft, and even as electronic warfare aircraft capable of Suppression of Enemy Air Defences duties (SEAD).
These spin-off versions were given their own NATO reporting names, and these tags were transferred to newer models of the Flanker made in Russia after the collapse of the Soviet Union.
The first of these is the Su-30 (Flanker ‘C’), a two-seater version which introduced ground-attack capabilities into service. A sub-variant known as the Su-30 MKK (Flanker ‘G’) was produced to fill a Chinese order in 1999, and a version known as the SU-30 MKI (Flanker ‘H’) was manufactured in large numbers for service with the Indian Air Force in 2002.
The Soviet Navy requested a version of the Flanker for carrier service, and Sukhoi obliged with the Su-27K, which was renamed the Su-33 (Flanker ‘D’) after 1991. This single-seat version was also ordered by China for naval and air force use, but this procurement program was the direct cause of a massive diplomatic wrangle between Russia and China.
Ordered as kits for assembly in China as the J-11A, over 100 airframes had been delivered before Russia became aware that the Chinese had illegally reverse-engineered the Su-27K and were manufacturing it as the J-11B. Amid accusations of design theft, the arrangement between the two countries was terminated in 2004.
One interesting spin-off of the basic Flanker design came about from an early proposal of an attack version featuring side-by-side seating, similar to that in the F-111. First flown in 1990 as the Su-27IB, the project was put on hold for many years due to lack of funds, but was revived in the new millennium.
Extensively modified with a new design as the Su-34 (NATO reporting name ‘Fullback’), this new aircraft first flew in 2006, and while it is a totally new design, the influence of the basic Flanker design can be seen in this platform.
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The last major version of the Su-27 to enter service was an extensively re-designed model optimised for air supremacy. In a similar story to that of the Fullback, the original version of the improved Su-27 was introduced into limited service, but after the Russian economy had improved in the early 2000s this variant had a design make-over to introduce new equipment and capabilities.
This new model was introduced as the Su-35S (Flanker ‘E’) and fitted with thrust-vectoring engines and sophisticated avionics and sensors, and first flew in 2008.
Even though this aircraft was conceived as an interim fighter until new stealth aircraft designs were introduced into service, this heavily armed, supermanoeuvrable aircraft was ordered in large numbers by Russia and China, and nations like Indonesia have expressed much interest in acquiring this platform. Many commentators have stated that the Flanker ‘E’ is the most lethal conventional (i.e. non-stealthy) combat aircraft in the world.
The Chinese-manufactured variants of the Su-27 (authorised versions and otherwise) are the J-11A/B basic fighter for use in the PLAAF, the J-15 single-seat naval fighter based on the Su-33, and finally the J-16 tandem-seat version for both naval and air force use. This variant is designed as a long-range strike version, also able to perform electronic warfare and SEAD duties.
Dimensions and performance figures shown here are for the basic Su-27 Flanker ‘B’, and as such are surpassed in later models of the aircraft mounting different engines and avionics upgrades.
The height of the Su-27 is 5.9 metres (19 feet 5 inches), with a length of 21.9 metres (71 feet) and a wingspan of 14.7 metres (48 feet). Empty, the Flanker ‘B’ weighs 16,400 kg (36,000 lbs) and has a gross weight of 23,400 kg (51,700 lbs). The MTOW of the Flanker is 30,450 kg (67,000 lbs). The internal fuel capacity of the Su-27 is 9,400 kg (20,700 lbs).
Early models of the Flanker were equipped with two Saturn AL-31F afterburning turbofans, each producing 17,000 lbs of thrust dry, and 27,000 lbs thrust when the afterburner is engaged. The Flanker ‘E’ is fitted with two thrust-vectoring AL-41F1S improved engines, with dry thrust of 19,400 lbs and an astonishing 32,000 lbs of thrust in emergency power.
The Su-27 has a top speed of 2500 km/h (1600 mph, M 2.35) at altitude, and has a service ceiling of 19,000 metres (62,000 feet). On internal fuel, the Flanker ‘B’ has a range of 3,350 km (2,190 miles). The Flanker is rated to 9G+ for manoeuvring, and has a thrust/weight ratio of 0.91, though this improves to 1.07 when less than 60% internal fuel is carried.
Armed with a single GSh-30-1 30 mm autocannon, with 150 rounds supplied for the gun and has a total of ten hard points under the fuselage and wings and can carry a load of 4,500 kg (9,700 lbs) of ordnance. This loadout can consist of radar-and-infrared guided air-to-air missiles, smart and unguided bombs, air-to-ground missiles and unguided rocket pods, or a combination of all these.
The Flanker is equipped with an air-intercept radar of a digital pattern, and the ‘E’ introduces phased-array radar for air-to-air use. It is equipped with modern avionics which includes radar warning and other defence equipment, and some models have a turreted infra-red seeker to employ in the off-boresight (wide-angle) firing of infra-red missiles.
Flankers of various types serve in over a dozen nations as front-line equipment, and privately-owned examples have even turned up in the United States. All models and derivatives of the basic Flanker version have operated around the globe, and have taken part in several minor conflicts until 2022. The Russian invasion of Ukraine has seen widespread use of the platform by both belligerents.
Russia has employed the Flanker in two wars against Georgia, in 1992-93 and again in 2008. The Flanker has also been employed in the Syrian Civil War, operated by Russian pilots in support of the Assad government in ground-attack roles, and patrolling the Syrian skies against incursions from Turkish military aircraft.
Russia and China have used the Flanker (or Chinese copies like the J-11) in long-range interceptions and incursions, with Russian aircraft probing NATO air defences and the PLAAF intruding into Taiwanese airspace.
Ethiopia employed the Flanker to shoot down Eritrean MiG-29 Fulcrums during the war between those nations between 1998 and 2000. Angola also employed the type during the Angolan Civil War, with at least one example being shot down by a man-portable air-defence missile (MANPADS).
Ukraine inherited nearly 70 Su-27s when the nation became independent in 1991. Along with the numbers of the MiG-29 Fulcrum, these aircraft are the most capable in the Ukrainian inventory at this time, and find themselves in combat during the current conflict against Russian ‘B’ models, along with later variants in Russian service.
From 2014 onwards, the Ukrainian General Staff made serious efforts to engage in training with Western air forces, and this increased competency along with the modification of Ukrainian Flankers to employ some Western ordnance has paid dividends in Ukrainian airspace.
Ukraine appears to be using the Flanker as a heavy strike fighter, with the lighter MiG-29 Fulcrum acting as fighter cover during these missions. This makes sense considering the large load-carrying capacity of the Flanker, but some reports state the Su-27 has been employed in aerial combat against Russian military aircraft as well. At least one Ukrainian Flanker has been spotted carrying AGM-88 HARM missiles, whilst on a SEAD mission over the Forward Edge of the Battle Area (FEBA).
While the original Flanker ‘B’ design may seem a bit dated today, constant updates ensure that the latest variants of the Flanker family remain as feared aerial opponents, easily equal to the 4th generation aircraft in many national inventories.
The Flanker ‘E’ is one of the most capable and deadly air-to-air fighters existing today, and nations equipped with this variant can be considered formidable opponents in both the air supremacy and long-range strike scenarios. With the ‘E’ model being referred to as the Super Flanker, it is apparent that the Flanker will remain a problem for many air forces to deal with for the immediate future.
Big, agile, heavily armed and with a very long range, the Su-27 has been a prime combat aircraft for several decades since the 1970s, and later models will continue to serve with both naval and air forces for some considerable time to come.
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It rightfully deserves its place as one of the premier combat fighters of the modern era, and will continue to inspire both dread and admiration for many years into the future.
- Crew: 1
- Length: 21.9 m (71 ft 10 in)
- Wingspan: 14.7 m (48 ft 3 in)
- Height: 5.92 m (19 ft 5 in)
- Empty weight: 16,380 kg (36,112 lb)
- Max takeoff weight: 30,450 kg (67,131 lb)
- Powerplant: 2 × Saturn AL-31F afterburning turbofan engines, 75.22 kN (16,910 lbf) thrust each dry, 122.6 kN (27,600 lbf) with afterburner
- Maximum speed: 2,500 km/h (1,600 mph, 1,300 kn) / M2.35 at altitude
- 1,400 km/h (870 mph; 760 kn) / M1.13 at sea level
- Range: 3,530 km (2,190 mi, 1,910 nmi) At altitude
- 1,340 km (830 mi; 720 nmi) at sea level
- Service ceiling: 19,000 m (62,000 ft)
- Rate of climb: 300 m/s (59,000 ft/min)