By Sayan Majumdar


New Delhi, 05 June 2005

With the sanctioned upgradation of Indian Navy’s Sea Harrier fighter aircraft, INS Viraat’s flight deck is all set to register a decent new look. A total of 14 Sea Harrier FRS51 will be updated, fitting these with Rafael Derby/Alto Beyond Visual Range Air-to-Air Missiles (BVRAAM) in tandem with Elta EL/M 2032 radars. Combat manoeuvring flight recorders and digital cockpit voice recorders will be added. Hindustan Aeronautics Limited (HAL) at Bangalore will carry out the upgrade. The upgradation was long overdue as the original combination of non-coherent pulse ‘Blue Fox’ radar and Magic 2 Within Visual Range Air-to-Air Missiles (WVRAAM) combination was critically inadequate in dealing with emerging threats in the Indian Ocean region. The upgradation of the Sea Harriers may also send a tacit signal that the Navy may be interested in the Royal Navy Command Cruiser HMS Invincible facing premature decommissioning and is capable of providing a robust Afloat Naval Headquarters useful for distant and amphibious operations.

The Sea Harrier was developed for Royal Navy requirements during the Cold War era and intended primarily for protection of shipping lanes in the North Atlantic from long-range air-launched missiles fired from Soviet Tupolev-95/142 “Bear” bomber/cruise missile platforms or submarine launched missiles using target coordinates supplied from “Bears” via data-link. The “Bear” usually operating at medium or high altitude could be detected by the ship’s radar to vector a Sea Harrier out to intercept it. In any case the Sea Harrier was essentially a back up to land-based air power, as it lacked the requisite speed of a “conventional” fighter. Unfortunately the concept of having an Advanced Short Take-Off & Landing (ASTOL) project with plenum chamber burning for mounting a Combat Air Patrol (CAP) for two and half hours at an unspecified distance from the mother ship failed.

However, in close combat the Sea Harrier is formidable. It is “stealthy” in visual terms, thanks to its small size and smokeless engine. With Vectoring In Forward Flight (VIFF) attributes it has a formidable turning capability. In spite of a modest fuel fraction, the economical turbofan engine with lack of reheat enables a maximum interception radius of around 740-km.

Yet, even during the Falklands conflict in 1982 in spite of great air combat success of the Royal Navy Sea Harrier fleet, the limitations and deficiencies were apparent. With no Airborne Warning & Control System (AWACS) platform support and often-minimal ship-borne control, the Sea Harrier fleet was forced to resort to the wasteful practice of standing patrols with an inherent risk of getting outnumbered. The deployment of aircraft carriers HMS Hermes and HMS Invincible well beyond the effective range of Argentine strike fighters also “stretched” the patrol area of the Sea Harrier fleet. No wonder, in the absence of radar lookdown capability, most sightings were made visually and chances were missed. However, on the flip side the Argentine fighters, operating from land bases were made to reach the Royal Navy fleet at “firm” subsonic speeds only to be decimated by the Sea Harriers. The Royal Navy tactics and the sheer skill and professionalism of Sea Harrier pilots held the key. The Royal Navy nuclear powered submarines for their part “cornered” the sole Argentine aircraft carrier ‘Vienticinco de Mayo’ in coastal waters constraining its operational flexibility to a considerable extent. In all the Royal Navy Sea Harriers registered around 28 “kills” without conceding a single loss in air-to-air combat, with around 23 “kills” registered by the AIM-9L Sidewinder WVRAAM.

But the all-WVRAAM armament in air-to-air role in shape if AIM-9L Sidewinder also made their deficiencies apparent. AIM-9L was touted as an “all-aspect” WVRAAM. Yet, although most missile launches were made from astern, the kill ratio achieved was only about 67 percent. At very low level in dense atmosphere the advertised range of AIM-9L was severely curtailed and the missiles fell “short” of even close targets. No wonder the Royal Navy promptly went for a combination of ‘Sea Vixen’ radar with AIM-120 AMRAAM BVRAAM, with Sea Harriers holding the distinction of being the first European fighter to be armed with AMRAAM.  

The Indian Navy for their part have selected the Israeli Active-Radar Homing (ARH) AAM referred to as Alto or Derby which shares design commonality with Python 4 WVRAAM with addition of mid-body wings. Derby has Look-Down/Shoot-Down capability and advanced programmable ECCM to operate under dense electronic warfare environments. Israelis claim a maximum range of 50-km.

For BVR engagements a Lock-On After Launch (LOAL) mode is used in which the missile employs inertial guidance immediately after launch until the seeker is activated and homes in on the target. Derby also has a very low minimum range and an option for Lock-On Before Launch (LOBL) mode and thus is also capable of being employed for short-range engagements. In the LOBL mode for short-range engagements, Derby's seeker can be slaved to the aircraft's radar or the pilot's helmet mounted cueing system. The seeker is activated before launch and guides the missile all the way to the target. The warhead and proximity fuse shares commonality with that of Python 4.

To support the IN Sea Harrier fleet embarked on INS Viraat the Airborne Early Warning (AEW) role the IN employs Russian Kamov-31 (also known as the Kamov-29 RLD) representing a further development of the Kamov-27 Anti-Submarine Warfare (ASW) helicopter. In terms of enhancement of endurance the helicopter will be fitted with a helicopter-to-helicopter in-flight refuelling capability although whirling rotor blades makes such a task very challenging, demanding expertise and concentration.

The Kamov-31 is fitted with the E-801M Oko (Eye) airborne electronic warfare radar which features a 6x1-metre planar array mounted beneath the fuselage. The radar is folded and stowed beneath the aircraft's fuselage before being lowered into a vertical position, to allow 360-degrees mechanical scanning once every ten seconds. The radar can simultaneously track up to 20 airborne or surface threats, and can detect fighter-sized aircraft from a range of 110-km to 115-km and surface ships at a horizon of 200-km from an altitude of 9840-ft. Some sources state an enhanced capability. 

The co-ordinates, speed and heading of a target gathered by the radar are transmitted via an encoded radio data-link channel to a ship-borne or shore-based command post facilitating introduction of airborne network centric warfare to the Indian Navy. As is apparent, the Kamov-31 will considerably free the IN Sea Harrier fleet from the wasteful practice of standing patrols by positioning them at advantageous co-ordinates before the enemy air platforms arrive at striking distance, a critical requirement in respect to limited speed of the Sea Harriers especially while dealing with enemy strike fighters and Long Range Maritime Patrol (LRMP) platforms like P-3C Orion armed with stand-off Anti-Ship Missiles (AShM).

Meanwhile the ASW capability of INS Viraat remains formidable, thanks to a combination of British and Russian ASW helicopters. INS Viraat previously known as HMS Hermes in British Royal Navy service perhaps remains as the only post-World War II aircraft carrier shouldering on a distinguished service well into twenty-first Century. One of the more photographed warships of all time, in Royal Navy service it played a critical “Cold War role” in North Atlantic and North Sea often “brushing” with one-time arch-rival Soviet Navy surface combatants. During Falklands War of 1982 its role as an aircraft carrier and Command Ship was of paramount importance, as Royal Navy would simply have failed to undertake the Falklands campaign without this particular ship.

Presently in Indian Navy service the ageing INS Viraat still represents a potent strategic force in the vital Indian Ocean region. INS Viraat having enjoyed such a distinguished service on three oceans is expected to “hold the fort” until INS Vikramaditya (ex-Admiral Gorshkov) joins the Indian Navy fleet sometime in 2007–2008. One may hope that such an illustrious warship will “obtain” a new role as a floating maritime museum much to delight of Indian and British naval officers and personnel who served on the ship at any point of time.   

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