The Su-33 (Su-27K) is a single-seat multi-purpose shipborne-decking fighter airplane with horizontal takeoff and horizontal landing capability, complete with folding wing and tail plane for hangar storage.
The Su-33 is intended for naval air superiority missions, the air defense and missile defense of a ship group, the destruction of any aerial, sea-surface and ground targets with missiles and bombs, as well as supporting the combat operations of other fleet air force units such as shipborne, missile-carrying, anti-submarine, radar surveillance, and other aircraft.
The Su-33 can also perform containment functions prior to engagement and maintaining an operational environment in the near and far maritime zones, which makes any aggression from the sea impractical or extremely difficult. The tactical operating range of the Su-33 is 1,200 km. The fighter is capable of barraging a designated area performing air defense and missile defense missions 500 kilometers away from its carrier over more than two hours. The use of a Su-33 leads to a one-and-a-half-fold to double increase in the strike capabilities of operational units in initial naval operations at a distance of 1,500-2,000 kilometers from the shore.
The USSR Navy’s carrier ships had long carried only vertical-takeoff-and-landing aircraft that could not compete with the US Navy’s aircraft taking off with the use of steam-driven catapults. In order to catch up, the Sukhoi Design Bureau mounted an effort to design and launch production of a new shipborne airplane based on the Su-27’s design in the mid-1970s. The Su-27K (shipborne) was to become the first domestically-produced heavy-class fighter capable of take-offs or landings on ship decks in the traditional fashion, i.e. with a take-off run and landing roll.
The Su-27K development project entered its active phase in 1982 when the government decided to launch construction of an aircraft-carrying heavy cruiser at the Black Sea Shipyard in Nikolaev, which was meant to provide air defense for the Navy’s ship groups in the world's oceans and seas. To achieve a shorter take-off distance for airplanes like the Su-27 and MiG-29, a takeoff ramp was designed in the nose section of the ship’s flight deck instead of a catapult. Such a concept required experimental testing. To test the engineering concepts for the take-off and landing of decking airplanes, explore the specific nature of seaborne aircraft operations, and train future sea-based aviation pilots, the government made the decision to set up a Research and Training Facility (NIUTK) in Crimea, which would later be renamed “Nitka” (Aviation Research and Training Complex).
In 1982-83, the first stage of ramp take-off tests and the ground stage of arrester gear landing tests were completed. N. Sadovnikov was the Design Bureau’s lead test pilot for that program. He was the first of the Design Bureau’s test pilots to successfully complete a ramp take-off on August 28, 1982. The testing of a no-flare landing and take-off from the new ramp version with a greater angle began with another modified test airplane in 1984. V. Pugachev operated the first deck running landing on September 1, 1984, and N. Sadovnikov successfully completed the first take-off from the new ramp on September 25, 1984.
The possibility of designing and producing a shipborne fighter was therefore proven in principle, and the Central Committee of the Communist Party of the Soviet Union and USSR Council of Ministers passed a resolution assigning the Sukhoi Design Bureau to develop the Su-27K, based on the Su-27’s design, on April 18, 1984. Earlier, the Mikoyan Design Bureau had been tasked with the development of a shipborne fighter based on the MiG-29’s design. Therefore, an informal competition for “a spot on deck” was initiated between the two Design Bureaus. A conceptual design review was completed in November, 1984, and detailed design documentation for the Su-27K (T-10K) was completed in 1985-86. The work was led by Deputy Chief Designer K. Marbashev.
Two initial test Su-27K airplanes were manufactured by the Design Bureau in cooperation with the production plant in 1986-87. The first flight of the T10K-1 test airplane was operated by the Design Bureau’s test pilot, G. Pugachev, on August 17, 1987, and N. Sadovnikov first took off in the T10K-2, the second test airplane, on December 22, 1987. V. Pugachev successfully landed the T10K-2 on the deck of aircraft-carrying heavy cruiser "Tbilisi" (subsequently renamed “Admiral Kuznetsov") for the first time in the history of national aviation on November 1, 1989.
Production of Su-27K airplanes was launched by KnAAPO in 1989, when the production plant manufactured a test airplane for static tests. The first flying prototype of the produced T-10K-3 airplane was assembled in early 1990. The first flight of the production Su-27K was completed on February 17, 1990 (by test pilot I. Votintsev). Six more Su-27K airplanes were produced by KnAAPO in 1990.
Official tests of the Su-27K were completed in 1994. A total of 24 Su-27K airplanes were produced by that time and reassigned to the Northern Fleet Base, home-base of the "Admiral Kuznetsov" aircraft-carrying heavy cruiser. The first four airplanes were ferried to Severomorsk from the production site in Komsomolsk-on-Amur on April 1993 and joined the 279th Naval Fighter Regiment (KIAP). The "Admiral Kuznetsov" aircraft-carrying heavy cruiser completed its first long oceanic tip to the Atlantic and the Mediterranean Sea during the period of December 1995 to March 1996.
The Su-27K was officially passed into service by presidential decree, and accepted by the Armed Forces of the Russian Federation and given the name “Su-33 shipborne fighter” on August 31, 1998.
A two-seat operational training version had been developed by the Design Bureau since the mid-1980s. Later, work on a new dual-cockpit version designated as the Su-27KUB (10KUB) would be started in the early 1990s. The test prototype model was manufactured at the production site in Komsomolsk-on-Amur in 1995-98; the final assembly was completed in Moscow, where a T10K-4 test airplane was used for modifications. The first flight of the 10KUB test prototype model was completed on April 29, 1999 by the plant’s test pilots V. Pugachev (Captain) and S. Melnikov (Co-Pilot). The airplane successfully passed the factory stage of tests. Finally, the 10KUB had the chance to receive the high praise of fleet air force pilots.
Operational control of the airplane at approach for landing on the deck of an aircraft-carrying cruiser is provided from a special landing bridge, where a team of approach control officers controls the movement of? the Su-33 along the approach path. The airplane is located by the ship’s radar and, as soon as it intercepts the initial part of the descent glide path, the flight is controlled by approach radar. The pilot visually controls the fighter’s descent path, guided by the observed color lights of the landing facilities. Landing is performed with little or no flaring, and with descent along the landing glide path at a 4-degree angle. Upon touchdown on the deck, the fighter’s arrester hook engages the arrester gear cable, and the airplane decelerates at a longitudinal acceleration rate of -3 to -4.5 over a 90- to 100-meter distance. Upon touchdown, the pilot sets the engines to maximum power to ensure that the airplane will be able to lift off from the deck and go around in case of landing hook engagement failure or cable break.
Su-33 is the first produced airplane in the world designed with a relaxed stability aerodynamic configuration and three lift surfaces. The all-movable horizontal canard installed on the wing extension improves pitch angle and control performance.
As the flight angle of attack grows, the deflected horizontal canard operates as a slotted leading edge for the inboard wing panel and, together with wing high-lift devices that are automatically deflected according to the angle of attack, substantially improves the aerodynamic performance of the airplane. This prevents losses in lift performance during maneuvers and eliminates buffeting at high angles of attack, which makes controlling the flight and aiming much easier for the pilot. Furthermore, the slotted leading edge effect prevents inadvertent stalling.
Installation of the horizontal canard also enables the implementation of a direct lift-level control system, which is achieved by the simultaneous deflection of the horizontal canard and trailing edge high-lift devices. Thus, the lift level under the wings of the Su-33 during landing is 1.5 times higher than that of the Su-27 fighter. The further increase in lift provided due to availability of the horizontal canard considerably extends trim and balance capabilities which, in turn, enables a substantial reduction in airplane speed during its landing on the carrier’s deck.
The design of the Su-33 also has a number of other features determining its naval deployment and application:
- Aerodynamic design enabling ramp take-off and arrester gear landing, as well as its deployment in the limited space of a ship’s hangar and flight decks. A landing deceleration hook is arranged under the shortened central tail boom, provided with an extension, retraction, and damping system. To minimize dimensions for airplane accommodation and storage at hangar and flight decks, and for lifting and lowering with elevators, the Su-27K airplane’s wing-fold axis was moved closer to the fuselage side during the design process, and the stabilizer (horizontal tail plane) was also designed with a folding capability. The central tail boom fin tip can be tilted upwards, and the nose pitot probe can be folded. Thus, the lateral dimensions of the airplane with folded wing and horizontal tail plane were reduced to match those of the MiG-29K.
- The landing gear was reinforced to enhance the airplane’s maneuverability on deck. Main landing gears were provided with reduced-diameter wheels; the nose landing gear has two wheels and can turn to plus or minus 70 degrees. Tire pressure was made higher than in the Su-27.
- The fighter’s integrated flight control and navigation systems communicate with ship systems and ground facilities.
- The fuel system has flight refueling capability, both as the refueled aircraft and as the tanker (able to transfer up to 6,000 kg of fuel at a 2,000 l/min flow rate). The r-shaped flight refueling probe, which can be retracted when not in use, is arranged in the fuselage nose section, to the left of the cockpit.
- With the version of the AL-31F engine boasting an additional so-called ”special” power setting, thrust can be momentarily increased to 12,800 kgf.
- Special technology was used in the design to enable operation of the airplane in aggressive marine environments (from coatings, materials, and the sealing of individual structural elements);
- Avionics equipment was protected from interference from the ship’s electromagnetic fields.
In addition, all landing gear struts are equipped with fittings for tie-down and towing using the ship’s facilities; the nose landing gear has special landing lights installed with a three-color indicator showing the airplane’s position on the glide path and landing speed to the Landing Signal Officer.
The emergency escape system includes an advanced K-36DM ejection seat which provides safe escape across the whole operational altitude and speed range, as well as when the airplane is moved on deck or at a parking stand.
Systems and airborne equipment
A remote-control system providing automatic control in all three channels was used in a shipborne fighter for the first time in history. High performance of the aerodynamic design and implementation of the “electronic stability” concept with the use of a fly-by-wire control system in all three channels provided the Su-33 with exceptional maneuverability along with unique stability and handling performance. The Su-33 can perform superior aerobatics such as the "Cobra," "Hook" and "Bell," which are of great tactical value and enable close maneuvering engagement in a brand new way. The automatic restriction of marginal flight conditions (normal acceleration and angle of attack) significantly increases flight safety and the airplane’s combat effectiveness as it allows the pilot to concentrate entirely on the accomplishment of mission objectives.
To facilitate fight control during contact with tanker aircraft, a special mode was introduced into the remote-control system which, according to the accounts of pilots, ensures a nearly 100% probability of successful air refueling. An automatic fuel transfer setting was added to the fuel gauging-and-metering system which allows the pilot to focus entirely on piloting. The flight refueling probe is provided with lights for refueling in twilight and at night.
The hydraulic system also saw considerable changes, to which additional functions of controlling the horizontal canard, new wing high-lift devices, outerwing- and stabilizer-panel folding, extension and retraction of the landing hook, refueling probe, and other elements were assigned.
The integrated flight-control and navigation systems include automatic control systems with auto-throttle, providing navigation with coordinate correction from satellite navigation and long-range navigation systems, as well as return to the ship and landing approach in automatic mode using the ship's system (landing is possible with weather minimums from 30 x 400 m, including the availability of fully-automatic approach at the runway, up to the touchdown).
The capability of setting inertial navigation system gyros and entering flight mission data in "rocking base" conditions is also provided.
The airplane’s integrated electronic countermeasures prevent detection by enemy ship-based and ground-based radar systems.
The Su-33 has a weapons control system with advanced pulse-Doppler side-sweeping airborne radar and an infrared search-and-track station that can locate, recognize, track, and determine the coordinates of aerial targets against ground or water background. The tracking of up to 10 targets per pass is provided, with automatic determination of the most dangerous target, and the simultaneous launch of missiles at multiple targets.
The airplane is equipped with a defense system of electronic support measures alerting the pilot when the airplane is irradiated by enemy radars. The strap-on electronic warfare equipment accommodated on wing tips can be used for active jamming.
Avionics equipment is protected from interference from the ship’s electromagnetic fields.
The cockpit is equipped with a CRT multi-function display replacing direct vision display, on which navigation, tactical, and aiming information can be displayed, as well as aircraft-systems monitoring data.
|wing span (m)||14.70 (8.35 with folded wings)|
|maximum take-off weight (kg)||33|
|normal take-off weight (kg)||26,67|
|maximum fuel reserve in integral tanks (kg)||9,5|
|maximum payload weight (kg)||6,500/8,000 on 12 hardpoints|
|Engine’s main performance data|
|type, model||afterburning turbofan engine AL-31F series 3|