Combat Aircraft of the Indian Air Force
The Su-27 (NATO designation Flanker) is the front line fighter aircraft designed by the Sukhoi Design Bureau. The export version is the Su-27SK.
A variant, the Su-30MK (NATO designation Flanker), has been sold to India with licensed local production to begin in 2000.
The aircraft is equipped to operate autonomously in combat over hostile territory, in escort of deep penetration strike aircraft, and in suppression of enemy airfields. The aircraft provides general air defense in cooperation with ground and airborne control stations.
The aircraft is equipped with a 30 mm gun and a range of missiles, rockets, and bombs mounted externally on ten hardpoints. The aircraft’s infra-red search and track system, laser rangefinder, radar, and helmet mounted target designator provide detection, tracking, and attack capability.
The range of air-to-air missiles carried by the Su-27K aircraft includes:
- R-27R1, all aspect medium range missile with semi-active homing
- R-27T1 all aspect medium range missile with infra-red passive homing
- R-73E all aspect close combat air-to-air missile with infra-red passive homing
The R-27R1 (NATO designation AA-10A Alamo-A) and the R-27T1 (AA-10B Alamo-B) has a range from 0.5 to 60 kilometres, with the aircraft flying from 20,000 to 27,000 m altitude and speeds up to 3,500 km/hour.
The R-73E (NATO designation AA-11 Archer) provides all-aspect target engagement in close, high maneuverability combat with load factor up to 12g. The range is from 0.3 to 20 kilometres.
Ordnance for air-to-ground missions include:
- free fall and retarded aerial bombs 100, 250, and 500 kg
- incendiary devices, 500 kg
- RBK cluster bombs, 25 and 500 kg
- unguided aerial missiles C-8, C-13 and C-25
The Su-27SK is equipped with a coherent pulse Doppler radar, Phazotron N001 Zhuk, with track-while-scan and look-down/shoot-down capability. The range of the radar against targets size 3 square metres is over 100 km in the forward hemisphere and 40 kilometres in the rear hemisphere. The radar has the capacity to search, detect, and track up to 10 targets with automatic threat assessment and prioritization.
The aircraft has an OEPS-27 electro-optic system which includes an infra-red search and track (IRST) sensor collimated with a laser rangefinder. The range of the electro-optical system against a reheated target is from 40 to 100 kilometres depending on the aspect angle presented by the target.
The Su-27SK is equipped with a new electronic countermeasures suite for individual aircraft, and for mutual and group protection in the forward and rear hemispheres. The countermeasures system includes a pilot illumination radar warning receiver, chaff and infra-red decoy dispensers, and an active multimode jammer located in the wing-tip pods.
The Su-27SK is powered by two AL-31F turbofan engines designed by the Lyulka Engine Design Bureau (NPO Saturn). Each engine has two air intakes, a primary wedge intake and a louvred auxiliary air intake. The twin-shaft turbo-fan engine has after-turbine flow mixing, a common afterburner, an all mode variable area jet exhaust nozzle, an independent start and a main electronic control and a reserve hydromechanical engine mode control system. The engine nacelles have a semimonocoque configuration. The high temperature sections of the engines are made of titanium alloy.
The cockpit is equipped with a single zero/zero ejection seat type Zvesda K-36MD. The pilot is equipped with a helmet mounted target designator.
The fly-by-wire system in the Su-27SK uses quadruple redundancy of transducers, units and interfaces of the vital control channels to perform the following functions:
- longitudinal control
- provision of stability and controllability for longitudinal, lateral and yaw control
- control of the aircraft configuration in maneuvers
- restriction of parameters to keep within g-load and angle of attack limitations
- decrease of aerodynamic loading to conform to limitations of aircraft structure
The automatic flight control is linked to the navigation system, weapon control and command guidance equipment. The automatic flight control carries out:
- stabilization of the aircraft angular position and flight altitude
- return of the aircraft to a straight and level flight path from any altitude
- programmed flight altitude, climb and descent
- control from ground and air direction posts
- self-guidance interface to the weapon control systems
- en-route flight, return to home airfield and landing approach by radio beacon.
The radio communications suite provides:
- voice and data, VHF/UHF radio communications between aircraft and ground control stations within sight range
- voice radio communication with ground control stations and between aircraft up to a range of 1,500 km
- an encrypted data link for combat information exchange between aircraft
- command guidance from ground control stations using automatic interception mode.
The Su-27SK is a highly integrated twin-finned aircraft. The airframe is constructed of titanium and high strength aluminum alloys. The engine nacelles are fitted with trouser fairings to provide a continuous streamlined profile between the engine nacelles and the tail beams. The fins and horizontal tail consoles are attached to tail beams. The central beam section between the engine nacelles consists of the equipment compartment, fuel tank and the brake parachute container. The fuselage head is of semimonocoque construction and includes the cockpit, radar compartments and the avionics bay. The glove, i.e. the leading section of the wing root, on the starboard side houses a 30 mm GSh-301 gun with 150 rounds of ammunition.