Aircraft Carrier Based AWACS – A NECESSITY

By Sayan Majumdar


New Delhi, 16 June 2006

The nature of airborne threat to Indian Navy surface combatants has undergone a significant change lately. At the turn of the millennium the optimum airborne threat was exemplified by enemy strike and Long Range Maritime Patrol/Anti-Submarine Warfare (LRMP/ASW) platforms armed with deadly accurate anti-ship missiles like AGM-84 Harpoon and Exocet AM39. The situation has altered significantly during past few years because of rampant violation of Missile Technology Control Regime (MTCR), in respect to cruise and ballistic missile technology in the Asian continent. These developments have necessitated the preferable tactics of destroying the attacking missile platform well before the missile is released to ensure a decent chance of survival of the defending vessels. Capabilities for execution of “outer-air battles” have assumed priority and an aircraft carrier based Airborne Warning & Control System (AWACS) platform to fulfill the role of the primary sensor, has become obligatory in these concepts. Fixed-wing AWACS platforms have superior coverage of airspace and more importantly have the ability to guide and control ship-borne fighters towards their targets, both in air defence and strike missions, an attribute lacking in the Airborne Early Warning (AEW) helicopter platforms.

The most successful aircraft carrier based AWACS platform is represented by Northrop Grumman E-2C ‘Hawkeye’, which in E-2A variant gained operational status aboard the CVA-63 USS Kitty Hawk. Operating off the coast of Vietnam in autumn 1965 in support of United States Navy (USN) F-4 Phantoms and F-8 Crusaders, they performed an armed Combat Air Patrol (CAP) role to cover strike elements. Subsequently Hawkeye platforms started to control strike missions, guiding USN strike packages of F-4 Phantoms and A-6 Intruders around high ground and defensive concentrations, and warning them of enemy interceptors in the vicinity.

However the primary role of the E-2C Hawkeye aircraft is to operate as an all-weather AWACS platform to the naval task force capable of area and on-station search. From an operating altitude of 25,000 to 30,000-ft, the Hawkeye warns the naval task force of approaching air threats and provides threat identification and positional data to interceptors. Secondary roles include strike command and control, surveillance, guidance of search and rescue missions including support for anti highjack operations and as a relay to extend the range of communications between the airborne platforms and the Combat Information Centre (CIC) of the parent aircraft carrier.

The E-2C with the APS-120 radar made its operational debut with “unit” VAW-123 aboard USS Saratoga bound for the Mediterranean Sea in September 1974. This version was first to acquire a decent “overland” capability. Hawkeye is usually the first “unit” to leave the aircraft carrier deck after commencement of air operations. At on-station search mode the E-2C flies at a height of around 25,000 to 30,000-feet at a distance of 370-km from the parent carrier initiating a constant orbit, gaining altitude steadily as the fuel burns off. The flaps are set at 10-degrees deflection to provide the optimum 3-degrees radar-scanning attitude. Thanks to the new Allison T56A-427 engines, the E-2C can cruise on station for more than four hours.

During the 1990s the then recently introduced APS-138 advanced radar processing system enabled detection, identification and tracking both over land and sea in excess of 450-km and with expanded computer memory was able to accomplish triangulation automatically. Advanced passive detection enabled “silent” recognition and classification of hostile electronic emissions at ranges well in excess of the onboard radar. A pair of Litton L-304 computers handled data processing. Data inputs or request for information were made either by means of an alphanumeric keyboard or by a light-pen which is usually used to “hook” a specific USN F-14 Tomcat interceptor to a specific target by feeding relevant target information to the interceptor weapons control system by means of a data-link.

The developing tactical situations were presented by means of the Hazeltine APA-172 control indicator group to the “mission control room” located in the rear fuselage directly beneath the radome and included the “trio” of Combat Information Centre Officer, Air Control Officer and the Radar Operator on identical crew stations of 10-inch diameter main radar display screens, providing data pertaining to target tracks and 5-inch alphanumeric auxiliary display. Independent control at each station enabled crewmembers to select relevant information and data to be presented including target symbols, velocity vectors, and disposition of friendly fighter forces, surface task groups and waypoints.

 Presently the radome houses the AN/APA-171 antenna supplied by Randtron Systems. The Lockheed Martin AN/APS-145 radar is capable of tracking more than 2,000 targets and controlling the interception of 40 hostile targets. One radar sweep covers 6 million cubic miles. The radar's total radiation aperture control antenna reduces sidelobes and is sufficiently robust against Electronic Counter Measures (ECM). Now it is capable of detecting hostile airborne targets at ranges greater than 550-km. Even cruise missiles with Radar Cross Section (RCS) of 1-metre square or less can be detected at around 185-km. This serves as a critical advantage as even hostile submarines are likely to make attack with sea-skimming anti-ship missiles and cruise missiles, thus ASW screening becomes analogous to air defence and the “presence” of incoming cruise missiles often will serve as a warning of the impending attack. The latest mission computers are equipped with an enhanced high-speed parallel processor. The Lockheed Martin AN/UYQ-70 advanced display system and computer peripherals provide the operators with multi-colour displays, map overlays, zoom facilities and auxiliary data displays.

Northrop Grumman, meanwhile expressed their eagerness to sell six “next-generation standard” E-2C Hawkeye 2000 AWACS aircraft to the Indian Navy which in “USN colours” made its first operational deployment in 2003 aboard USS Nimitz in support of Operation Iraqi Freedom. Hawkeye 2000 features a smaller and lighter Raytheon Mission Computer Upgrade (MCU) based on open architecture commercial off-the-shelf (COTS) technology, with increased memory and faster processing. More importantly Co-operative Engagement Capability (CEC) consists of processor, data distribution system and antenna and to enable Hawkeye 2000 to perform real-time battle management, fusing and distributing information from sources such as satellite and ship-borne radar. Also included in the “package” are Lockheed Martin Advanced Control Indicator Set (ACIS), Satellite Communications (SATCOM) and pristine navigation and flight control systems.

In response to the projected sale of Hawkeye 2000, the Indian Navy would do well to redesign the flight-deck of its 37,500-tons Indigenous Aircraft Carrier (IAR) under construction at Cochin Shipyard Limited (CSL), Kochi to incorporate a Conventional Take-Off Landing (CTOL) capability with steam catapults. With IAR construction at an initial stage incorporation of CTOL capability will not be a much demanding proposition considering the dimensions of the flight deck and American assistance is perhaps available because of emerging strategic and business equations. Hawkeye 2000 platforms will be ideally complemented by Indian Air Force PHALCONS. Hawkeye meanwhile remains well within its development cycle with research proceeding on the next-generation, E-2E Advanced Hawkeye, to be fitted with a sophisticated next-generation solid-state, electronically steered Ultra-High Frequency (UHF) radar, Theatre Missile Defence (TBM) capabilities, multi-sensor integration and a Northrop Grumman Navigation Systems tactical cockpit.

Aircraft carrier based Hawkeye 2000 will prove to be invaluable in enabling Indian Navy MiG-29K/KUBs to establish local air superiority in open oceans even within the range of enemy fighter and strike aircraft and will be instrumental in intercepting and destroying enemy strike and Long Range Maritime Patrol/Anti-Submarine Warfare (LRMP/ASW) platforms at great distances effectively debarring them from conducting LRMP/ASW and anti-shipping operations and engaging incoming cruise missiles. For interception of cruise missiles a possible further development of the MiG-29KUB platform with even more powerful radar, preferably an Active Electronically Scanned Array (AESA) type, alongside encrypted TKS-2/R-098 Intra-Flight Data Link (IFDL) will permit networking of multiple MiG-29KUB platforms effectively providing additional Airborne Early Warning (AEW) coverage of respective sectors alongside vectoring appropriate fighters in pursuit. Exercising a significant proportion of MiG-29KUB option will also enhance operational capabilities in sphere of electronic warfare and long-range interdiction. MiG-29K/KUB flight and navigation system built on an open architecture principle around MIL-STD-1553B standard Databus will enable integration of diverse weapons and sensors conceptually including “outer-air battles” specific types like the 150-km range European MBDA Meteor Beyond Visual Range Air-to-Air Missile (BVRAAM) alongside the “monster” Indo-Russian R-172.

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