Su-27 | |
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Su-27UB of the Russian Knights aerobatic team | |
Role | Air superiority fighter |
Manufacturer | Sukhoi Design Bureau |
First flight | 20 May 1977 |
Introduced | December 1984 |
Status | In production/in service |
Primary users | Russian Air Force Chinese Air Force Ukrainian Air Force Indian Air Force |
Produced | 1984-current |
Number built | 680 |
Unit cost | US$35 million |
Variants | Su-30 Su-33 Su-34 Su-35 Su-37 Shenyang J-11 |
The Sukhoi Su-27 (Су-27 in the Cyrillic alphabet) (NATO reporting name ‘Flanker’) is a jet fighter plane originally manufactured by the Soviet Union, and designed by the Sukhoi Design Bureau. It was intended as a direct competitor for the new generation of American fighters (which emerged as the F-14 Tomcat, F-15 Eagle, F-16 Fighting Falcon, and F/A-18 Hornet), with long range, heavy armament, and very high agility. The Su-27 most often flies air superiority missions, but is able to perform almost all combat operations. Its closest American counterpart is the F-15 Eagle.
From the Su-27 design came several related developments. The Su-33 ‘Flanker-D’ is a Fleet Defense Interceptor that was developed from the Su-27 design for use on aircraft carriers. The main differences include a tail hook and canards. The Su-30 is a two-seat, dual-role fighter for all-weather, air-to-air and deep interdiction missions. Further versions include the Su-34 ‘Fullback’ strike variant and the Su-35 ‘Flanker-E’ improved air defense fighter.
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In 1969 the Soviet Union learned of the United States Air Force’s selection of McDonnell Douglas to produce the Fighter Experimental design (which was to become the F-15 Eagle). In response to that upcoming threat, the Soviets instituted the PFI (perspektivnyi frontovoy istrebitel, Advanced Frontline Fighter) program for an aircraft that could match the new American fighter on its own terms.
When the specification proved too challenging and costly for a single aircraft in the number needed, the PFI specification was split into two: the LPFI (Lyogkyi PFI, Lightweight PFI) and the TPFI (Tyazholyi PFI, Heavy PFI). THE LPFI program resulted in the MiG-29, a relatively short-range tactical fighter, while the TPFI program was assigned to Sukhoi OKB, which eventually produced the Su-27 and its various derivatives. The TPFI program is similar to the American F-X program, which resulted in the F-15 Eagle, while the LPFI program is similar to the LWF program, which spawned the F-16 Fighting Falcon and the Northrop YF-17, which itself led to the F/A-18 Hornet.
The Sukhoi design, which was altered progressively to reflect Soviet awareness of the F-15's specifications, emerged as the T-10 (Sukhoi's 10th delta wing design), which first flew on 20 May 1977. The aircraft had a large delta wing, clipped, with two separate podded engines and a twin tail. The ‘tunnel’ between the two engines, as on the F-14 Tomcat, acts both as an additional lifting surface and hides armament from radar. While being developed, it was spotted by a spy satellite at the Zhukovsky flight test center near the town of Ramenskoe, resulting in the temporary codename of Ram-K. It was believed that the Ram-K was being developed in two versions: a swing-wing fighter similar in function to the Grumman F-14 and a two-seat fixed wing interceptor aircraft which in fact turned out to be the unrelated Mikoyan MiG-31.
The T-10 was spotted by Western observers and assigned the NATO reporting name ‘Flanker-A’. The development of the T-10 was marked by considerable problems, leading to a fatal crash on 7 May 1978. Extensive redesigns followed, and a heavily revised version, the T-10S, made its first flight on 20 April 1981. This, too, had considerable developmental problems, leading to another fatal crash on 23 December 1981.
The production Su-27 (sometimes Su-27S, NATO designation 'Flanker-B') began to enter VVS operational service around 1984, although manufacturing difficulties kept it from appearing in strength until 1986. The Su-27 served with both the PVO and Frontal Aviation. In V-PVO service it was primarily an interceptor, supplanting older aircraft like the Sukhoi Su-15 and Tupolev Tu-28. Although the ‘Flanker’ has some capacity to carry air-to-ground weapons, in Frontal Aviation service its primary role was neither air support nor battlefield air superiority--it was intended as a sort of aerial interdictor, tasked with fighting its way past enemy (presumably NATO) lines to strike tanker and AWACS aircraft. Soviet planners knew that NATO forces possessed a considerable advantage because of these assets, and believed that attacking them directly would limit NATO’s ability to maintain an extended air campaign. The Su-27 retains that role in CIS service, with later marks being equipped to carry the new Novator KS-172 AAM-L long-range anti-AWACS missile.
From 1986 a special Su-27 designated P-42, rebuilt from the prototype T-10S-3 aircraft and stripped to minimum weight, began to set the first in a series of performance records for rate of climb and altitude, the aircraft setting 27 new class records between 1986 and 1988.
The Su-27’s basic design is aerodynamically similar to the MiG-29, but it is substantially larger. It is a very large aircraft, and to minimize its weight its structure has a high percentage of titanium (about 30%, more than any of its contemporaries). No composite materials were used. The swept wing blends into the fuselage at the leading edge extensions and is essentially a delta, although the tips are cropped for wingtip missile rails or ECM pods. The Su-27 is not a true delta, however, because it retains conventional tailplanes, with two vertical tailfins outboard of the engines, supplemented by two fold-down ventral fins for additional lateral stability.
The Su-27’s Lyulka AL-31F turbofan engines are widely spaced, both for safety reasons and to ensure uninterrupted airflow through the intakes. The space between the engines also provides additional lift, reducing wing loading. Movable guide vanes in the intakes allow Mach 2+ speeds, and help to maintain engine airflow at high alpha. A mesh screen over each intake prevents debris from being drawn into the engines during take-off.
The Su-27 had the Soviet Union’s first operational fly-by-wire control system, developed based on Sukhoi OKB’s experience in the Sukhoi T-4 bomber project. Combined with relatively low wing loading and powerful basic flight controls, it makes for an exceptionally agile aircraft, controllable even at very low speeds and high angles of attack. In airshows the aircraft has demonstrated its maneuverability with a Cobra (Pugachev’s Cobra) or dynamic deceleration — briefly sustained level flight at a 120° angle of attack. Thrust vectoring has also been tested (and is incorporated on later Su-30MKI and Su-37 models), allowing the fighter to perform hard turns with almost no radius, incorporate vertical somersaults into level motion and limited nose-up hovering.
The naval version of the ‘Flanker,’ the Su-27K (or Su-33), incorporates canards for additional lift, reducing take-off distances (important because the aircraft carrier Admiral Kuznetsov has no catapults). These canards have also been incorporated in some Su-30s, the Su-35, and the Su-37.
In addition to its considerable agility, the Su-27 uses its substantial internal volume for a large internal fuel capacity. In an overload configuration for maximum range, it can carry 9,400 kg (20,700 lb) of internal fuel, although its maneuverability with that load is limited, and normal load is 5,270 kg (11,620 lb).
The Su-27 is armed with a single Gryazev-Shipunov GSh-30-1 30 mm cannon in the starboard wingroot, and has up to 10 hardpoints for missiles and other weapons. Its standard missile armament for air-to-air combat is a mixture of Vympel R-73 (AA-11 Archer), Vympel R-27 (AA-10 'Alamo') weapons, the latter including extended range and IR guided models. More advanced Flanker variants (such as Su-30, -35, -37) may also carry Vympel R-77 (AA-12 Adder) missiles.
The Su-27 has a high-contrast tuneable HUD and a helmet-mounted sight capability, which, paired with the R-73 missile and the plane's superb agility make it one of the world's best dogfighter aircraft.
The radar proved to be a major developmental problem for the Su-27. The original Soviet requirement was very ambitious, demanding a multi-target engagement capability and 200 km range against "bombers" (16 sq.m RCS to match a Tu-16). This would greatly exceed the detection range of the F-15’s APG-63 (about 180 km vs a 100 sq.m RCS target) and be broadly comparable to the 1-ton Zaslon phased array radar used on the MiG-31.
To achieve this at a reasonable weight, the design team came up with a radar using electronic scanning for elevation and mechanical scanning for azimuth. Unfortunately, it proved too much for the Soviet microelectronics industry in the 1970s to achieve, and by 1982, the original Myesch program had to be abandoned and a less capable alternative array was selected. To make up the lost time, many matured technologies from the N019 Topaz radar, including an enlarged version of the twist-cassegraine array, on the MiG-29 was used, and as a result, the resulting N001 radar shared the same TS100 signal processor used on N019 Topaz radar, while N001V, the successor of N001, shared the same TS101M signal processor with N019M, the successor of N019. The radar only achieved a 140 km detection range versus the Tu-16, and could only engage a single target. Even then, the radar was initially beset by reliability problems and this caused the N001 to be accepted for service in 1991, half a decade after the Su-27 first entered service in 1986.
The first of the N001 series radar, the Tikhomirov (NIIR) N001 (NATO ‘Slot Back’), is a pulse-Doppler set with track-while-scan capability, but its processor is relatively primitive, making it vulnerable to false alarms and blind spots, as well as being more difficult to use. During the years, under the chief designer of N001 radar, Professor Viktor Konstantinovitch Grishin, the N001 radar has been upgraded many times, resulting in derivatives including N001V, N001VE, N001VEP, all of which are in service, including those exported Flankers. Professor V.K. Grishin was the chief designer of Zalson S-800 passive phased array radar on MiG-31, and the expertise would later contribute to the design of the replacement phased array radars for the N001 series.
It was apparent that there was limited room for improvement in the N001 series radar, and the Su-30 and Su-35/37 aircraft have the vastly superior Tikhomirov (NIIR) 'Bars' (Panther) N011M with a passive electronically scanned array, improving range, multiple target capability, and sensitivity. The Bars (Panther) radar is scheduled to be replaced by an even more capable successor, Irbis (Snow leopard)-E phased array radar in the near future. Tikhomirov (NIIR)’s competitor, Phazotron (NIIP) also offered similar radar with passive electronically scanned array.
The Su-27 has an infrared search and track (IRST) system in the nose just forward of the cockpit, which also incorporates a laser rangefinder. This system can be slaved to the radar, or used independently for "stealthy" attacks with infrared missiles (such as the R-73 and R-27T/ET). It also controls the cannon, providing greater accuracy than a radar sighting mode.
While the Su-27 and its immediate descendants (Su-35 and -37) have outstanding maneuverability and performance, the airframe design lacks stealth features, so the radar cross section (RCS) is large.
The Su-27 has seen limited action since it first entered service. Ethiopian Su-27s reportedly shot down five Eritrean MiG-29s;[1] in February 1999 and another on May 16, 2000.[2][3] The Su-27s were also used in CAP (Combat Air Patrol) missions, suppression of air defense, and providing escort for fighters on bombing and reconnaissance missions.[4]
In Angolan service, one Su-27 was shot down by a SA-14 MANPADS fired by UNITA forces on November 19th, 2000. Angolan Su-27 entered service in mid 2000.[1][5]
Recently, in the 2008 South Ossetia War, Russia was using Su-27s to gain airspace control over Tskhinvali, the capital city of South Ossetia.[6][7]
Around 680 Su-27s were manufactured by the Soviet Union and Russia. This total includes only Su-27s and not later derivative aircraft.
Data from KNAAPO Su-27SKM page,[14] Sukhoi Su-27SK page,[15] Gordon and Davison[16]
General characteristics
Performance
Armament
The Su-27 is in a starring role in the SSI flight simulator game Su-27 Flanker.
It also appears in the sequel Lock On, in fact in this game among other aircraft you can fly the SU-27 Flanker B and the naval variant SU-33 Flanker D.
Related development
Comparable aircraft
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