Sukhoi Su-27

Sukhoi Su-27
File:Su-27.jpg Two Sukhoi Su-27s taking off
Description
Role	Fighter aircraft/air superiority fighter
Crew	1 Officer
First flight	1977
Entered service	1986
Manufacturer	Sukhoi Design Bureau, Russia
Dimensions
Length	21.9 m	72 ft
Wingspan	14.7 m	48 ft 3 in
Height	5.93 m	19 ft 6 in
Wing area	46.5 m²	501 ft²
Weights
Empty	16,380 kg	36,100 lb
Loaded	23,000 kg	50,690 lb
Maximum takeoff	33,000 kg	62,400 lb
Powerplant
Engines	2 Lyulka AL-31F turbofans
Thrust	122.8 kN	27,600 lbf
Performance
Maximum speed	2,500 km/h at altitude	1,550 mph
Combat range	1,500 km	930 mi
Ferry range	3,900 km	2,420 mi
Service ceiling	18,500 m	60,700 ft
Rate of climb	19,500 m/min	64,000 ft/min
Armament
Guns	30 mm GSh-30-1 cannon with 150 rounds
Missiles	8,000 kg (17,600 lb) on 10 external pylons Up to 6 medium-range AA missiles R-27, 4 small-range thermal-seeking AA missiles R-73 Su-27IB can be used to launch X-31 anti-radar missiles, air-to-ground missiles X-29L/T (laser/TV guidance, which may be projected to helmet), KAB-150 and UAB-500 bombs with laser, TV, or IR guidance

The Sukhoi Su-27 (NATO reporting name 'Flanker') is a Russian fighter aircraft designed by the Sukhoi Design Bureau (SDB). It was intended as a direct competitor for the new generation of American fighters (which emerged as the F-14, F-15, F-16, and F/A-18), with exceptional 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. Some believe the Su-27 to have been born from a competition between Sukhoi and Mikoyan-Gurevich, given the Su-27's and MiG-29's similar shape. This is not so. The Su-27 was designed as an interceptor, where as the MiG-29 was designed to fill the role of short range fighter.

The Su-33 Fleet Defense Interceptor was built off of the Su-27 design. Main differences include a tail hook and "canards" (forwardly placed winglets used as elevators and ailerons). Given the purpose of this interceptor, one would say that its closest counterpart is the American F-14 "Tomcat", where as the Mikoyan-Gurevich MiG-29K would be analogous to the F/A-18 "Hornet".

The Su-30 is a two-seat, dual-role, fighter for all-weather, air-to-air and deep interdiction missions.

Background

In 1969 the Soviet Union learned of the USAF'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 Frontal 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 (Logiky PFI, Lightweight PFI) and the TPFI (Tyazholyi PFI, Heavy PFI), just as the F-15 program spawned the Lightweight Fighter (LWF) program that produced the F-16 and YF-17. Sukhoi OKB was assigned the TPFI program.

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. It was spotted by Western observers and assigned the NATO reporting name 'Flanker-A'). The T-10's development 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 teething 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 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.

Design

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 mimimize 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, which is blended into the fuselage at the leading-edge extensions (LEX), is essentially a delta, although the tips are cropped, enabling them to carry 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 insure 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 manoeuvrability 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-35 models), allowing the fighter to perform hard turns with almost no radius, incorporate vertical somersaults into level motion and limited nose-up hovering. The usefulness of the 'Flanker's' maneuverability in real-world combat is hotly debated, with some experts claiming it is inferior to the F/A-22 Raptor and Eurofighter Typhoon. With the advanced capability of modern air-to-air missiles, its turn performance may be of little actual benefit in a real fight. Of course, as history has often demonstrated, pilot training and strategy is often of far greater significance than raw performance. Nonetheless, the Su-27 is today one of the world's most agile aircraft, civilian or military.

The naval version of the 'Flanker,' the Su-33K, incorporates canards for additional lift, reducing take-off distances (important because the Admiral Kuznetsov aircraft carrier has no catapults). These canards have also been incorporated in some Su-30s and the Su-35.

In addition to its considerable agility, the Su-27 uses its substantial internal volume for a very 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 advantage is that for long-range missions, the Su-27 rarely requires drop tanks, reducing drag and leaving its pylons free for weapons.

The Su-27 is armed with a single Gryazev-Shipunov GSh-30-1 30 mm cannon in the starboard wingroot, and has up to 14 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, and Vympel R-77 (AA-12 'Adder').

The limitation of the Su-27 is its cockpit and avionics. The Su-27 has a HUD, but it does not have a true HOTAS control system, nor does it have modern multi-function displays. (Later Su-30 and Su-35 aircraft have a 'glass' cockpit, designed by the French company Sextant Avionique.) The original radar, the Phazotron N-019 (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. Su-30 and Su-35 aircraft have the vastly superior Phazotron 'Bars' N-011M with an electronically steered antenna, improving range, multiple target capability, and sensitivity.

This is supplemented by a 'stinger' between the engines that carries a radome for a rear-aspect radar, providing aft coverage and the potential for rear-firing missiles.

The Su-27 has an infrared search and track (IRST) system in the nose just foreward of the cockpit, which also incorporates a laser rangefinder. This system can be slaved to the radar, or used independently for "stealthy" attacks. It also controls the cannon, providing greater accuracy than a radar sighting mode.

Production and users

Around 680 Su-27s were manufactured by the USSR, and 400 are in service with the Russian Tactical Air Force. Of the CIS member states, Kazakhstan has around 30 and is due a further 12 under agreement; Belarus has, possibly, 20; Ukraine has around 60; Uzbekistan perhaps 25.

China received 26 in 1991-92 and a further 24 in 1995-96 before signing a agreement in 1998 for licensed manufacture of 200 as the J-11. Vietnam has twelve and has ordered a further 24. Ethiopia has 8 Su-27A and 2 Su-27U. Malaysia on the other hand has ordered 18 Su-30MKM in 2003 worth US$900 million and expecting deliveries in 2006. Indonesia has 2 Su-27 and 2 Su-30KI. About six went to Eritrea, eight to Angola, and 14 to Syria. Finally, India ordered 50 Su-30MKI aircraft with more powerful AL-31FP engines, advanced avionics, canards, and thrust vectoring. HAL has a license to manufacture up to 140 additional aircraft through 2020.

Sources

Source for technical and weaponry data: Modern Combat Aircraft: Reference guide pp. 50-51 Minsk, "Elida", 1997, ISBN 985-6163-10-2 (Russian language).

Related content

Related development: MiG-29 - Sukhoi Su-32 - Sukhoi Su-35 - Sukhoi Su-35 - Sukhoi Su-37

Comparable aircraft: F-15 Eagle

Designation sequence: Su-24 - Su-25 - Su-26 - Su-27 - Su-28 - Su-30 - Su-32 - Su-33 - Su-34 - Su-35 - Su-37

External links

• Russkiye Vityazi (Russian Knights) Acrobatic Team
• GlobalSecurity.org
• Sukhoi Su-27 page by the Federation of American Scientists