An IDC Analysis


New Delhi, 29 June 2006

In 21st century warfare, Aerial Early Warning (AEW) has become an inescapable tool for any modern war fighting force. The West calls these changes in warfare technology revolution in military affairs (RMA), but it was the Russians who called it Transformation. We would like to call it Transformation In Warfare (TIW) –– a recurrent happening since the arrival of the bow and arrow followed by the cavalry, the use of elephants in India, then gunpowder, guns and cannon, which the British used to defeat Indians including the French trained forces of Tippu Sultan.

Then came the missiles and today computing technology and electronics have given rise to the concept of Command, Control, Communications, Computer, Intelligence, Surveillance and Reconnaissance (C4ISR), which is the new buzz word and AEW is an important component. Lord Wellington who defeated Napoleon had said, “I always dream of how I can see what is over the hill to deploy my forces,” and that is what AEW is all about –– the ability to look far and over the hill.

There can be no long range missile deployment (a la BrahMos) or aerial warfare or interception of the incoming fighters over land or sea for the Navy and Air Force without AEW. AEW is also a source to lick the anti missile defence problem. The Indian Navy realised this and ordered 8 KA-31 AEW helicopters, which arrived in 2003 and they have a rotating foldable antenna for AEW.
Shashank Sinha enlightens us further with his study on the history of AEW and its progress in India. Even the Pakistan Air Chief has just ordered the ERIEYE radars worth $1 billion from Sweden and we post the story below.

Dawn of AEW & C Operations in the Indian Military

By Shashank Sinha

The Indian Navy scored a first in 2003 when it inducted Kamov-31 helicopters in its naval air arm, thereby heralding the introduction of airborne early warning systems (AEW & CS) in Indian armed forces. With the IAF preparing to take delivery of its own AEW & CS aircrafts by 2007 it is imperative to take a look at the origins and operations of such systems worldwide.

Origins of AEW & CS

Origins of AEW & C systems can be directly traced to a research programme of US Navy (USN) in June 1942. Initiated as “Project Cadillac”, the Massachusetts Institute of Technology was entrusted with development of airborne radar capable of detecting enemy aircraft and warships far beyond the horizons of existing ship borne radars. The need for such a system was more accentuated during the bitter fighting around Okinawa islands in the pacific theatre of World War II, where the USN was reeling under kamikaze suicide attacks and wanted a much expanded threat warning system for its fleet. Cadillac resulted in tests, beginning from August 1944, of a modified Grumman TBM-3 Avenger torpedo bomber, fitted with AN/APS-20 radar in a large ventral radome and accommodation in the aft fuselage for a radar operator. Follow on Cadillac conversion programmes were based on naval B-17 Flying Fortress bombers and Super Constellations, the USN opting for the WV-2 Super Connie and APS-20 combinations. The USAAF (later USAF) ordered a version of Navy WV-2, designated as the RC-121 Warning Star (later EC-121) in 1951. With the soviet manned bomber threat looming large, they were used primarily to work with and extend the coverage of NORAD (North American Air Defence). These were the very first AEW system to be developed and deployed.

Rapid development of radar and electronics technology was making possible substantial expansion of the situational awareness envelope for the military commanders, but it was the immediate tactical exigencies of a conflict which set the stage for the next big step for AEW & C operation.

EC-121 ‘Warning Star’: AEW & C Over Vietnam

A major problem faced by American war planners in Vietnam was the lack of comprehensive land based radar coverage. An incident in 1965 involving downing of two F-105s by NVAF (North Vietnamese Air Force) MiGs in air combat glaringly demonstrated that early detection and warning of enemy fighter activity was essential for reducing aircraft losses. As the surface based radar net was unable to do the job the USAF looked on to application of AEW & CS for the first time in combat conditions. EC-121s from 552 AEW & C Wing was brought in to fill the gap.

They operated from bases in Thailand flying patrols over the Gulf of Tonkin looking out for NVAF air activity and guiding American air operations. These operations saw an increased usage of AEW platforms as a flying air traffic control, which was later to become an essential part of all modern AEW &CS missions. By 1967 they also started actively guiding air combat. On 24th October 1967 an EC-121 guided an F-4D phantom II fighter onto a Vietnamese MiG-21 marking the first time an aircraft had been successfully intercepted and destroyed through direction given by an airborne controller. In many ways the warning star provided the genesis of modern day AEW &Cs operations and reaffirmed its status as an integral part of future air campaigns. These operations over South East Asia gave birth to the tactics so successfully demonstrated in the 1991 gulf conflict.

E-2 Hawkeye and E-3 Sentry –– AEW Comes of Age

Boeing E-3 ‘Sentry’ popularly known as AWACS (Airborne Warning and Control System) is regarded as the first fully “evolved” system to come into service. And although it entered service almost 25 years ago, it is still considered as the finest AEW system flying today. It certainly is the most popular. It made a dramatic debut through operation ‘desert shield’ immediately after the Iraqi invasion of Kuwait. In the days that followed the E-3s flew some 845 sorties and logged more than 5000 hours of on station time, directing around 120,000 coalition air sorties, impressive figures by any standard. The fact that out of the 40 air to air kills during that war 38 were controlled by the E-3 is an affirmation that AEW capability has become the fulcrum for the conduct of air operation.

The ‘AWACS’ programme grew out of a USAF Air Defense Command and the Tactical Air Command requirement in 1966 for an AEW system which was considerably advanced in every aspect over the EC-121 then in service. The Boeing 707 platform was chosen and E-3 AWACS reached initial operating capability some 11 years later. The last of the 34 aircraft built were handed over to the USAF in 1984. The primary radar housed in the roto-dome is the Northrop Grumman AN/APY-1/2 look down unit, scanning at 6 revolutions per minute. It has a view of 360 degree scanning air and sea targets simultaneously, and a range of more than 320 km when operating at operational altitude. The aircraft is equipped with 14 command and control consoles for data output enabling it to be used a full fledged battle management centre. Upgrades are underway to improve the ability of the radar to detect small and stealthy targets. GPS navigation, enhanced computer memory, better ESM (Electronic Support Measures) and installation of JTIDS (Joint Tactical Information Distribution System), should suffice to keep the E-3 on the cutting edge for now.

The role of the AWACS itself has changed considerably and evolved over the years since it was introduced in late 1970s and early 1980s to support strategic air defence against Soviet bombers controlling fighter assets like the F-4 and F-106 in closely controlled intercepts in a rather narrow strategic environment. Later, while the E-3s role remained attentive to Soviet Bomber threat; it also began to greatly focus on control of tactical assets in the tactical environment. By the beginning of the 1990s during the Gulf war, AWACS provided control and battle management, theater wide on the operational level. For this it relied more on interoperability with other surveillance assets and ground centers. Also conducive to such a role was arrival of advanced fighters such as the F-15 and F-16 which required lot less intercept control assistance and enjoyed a greater degree of autonomous capability because of their onboard advanced sensors. As a result the AWACS role has shifted to a much broader one of “tactical advisor” operating on a much wider tactical area.

The E-2 Hawkeye entered service in 1973 as the standard ship borne AEW platform of USN. Its latest Lockheed Martin AN/APS-145 radar handles more than 2,000 targets and controls 40 interceptions while capable of detecting aircraft at ranges greater than 550km with one radar sweep covering 6 million cubic miles. A comprehensive communications Suite includes UHF and HF data link plus JTIDS to provide secure voice and data communication. Various upgrades are underway to enhance capabilities of this already impressive platform with fitment of new solid state electronically steered UHF radar. The role of the E-2 is also changing much as the AWACS, but providing early warning of approaching threats to carrier battle group still remains the primary mission. This has mostly to do with the inherent vulnerability of naval assets from which the E-2 operates. Many international operators operate the E-2 as land based AEW aircraft, Taiwan and Israel being the two most prominent. At the hands of the latter the E-2 performed remarkably well during the Bekka valley confrontation of 1983 showing its versatility. It also proved that sound tactics are of more importance to exploit the advances offered by any system.

From Moss to Mainstays –– The Russian Experience

Russian efforts in getting together an AEW system have traditionally been guided by a very different set of needs. Being a big continental power with a huge geographical land mass and surrounded by NATO bases, USSR was always very concerned about homeland air defence. Their biggest worry lay in Eurasian arctic regions where the radar net was not comprehensive. These areas often stationed PVO regiments armed with heavy long range interceptors capable of high endurance missions. One way to tackle the problem was an AEW system which materialized in the shape of TU-126 (NATO: ‘Moss’) radar picket aircraft in 1971. It was based on the Tu-114 turboprop airliner and 12 airframes were modified to carry roto-dome radar. Overall capabilities remained modest, mainly due to poor radar but it remained in service till mid 1980s complementing ground radar network. It must be said however that, from its very outset the Tu-126 was never intended to carry out the same mission criteria as the AWACS. It was chiefly used as a mobile airborne radar station operating within borders in support of existing land based radar. A job it did reasonably well.

From mid 1980s a new AEW aircraft the A-50 began entering service to replace the Tu-126. Based on the world beating Il-76 military freighter it carries a now too familiar roto-dome housing the ‘Schmel-M’ radar. It is a vast improvement being able to detect a small object bearing an effective target area of 3 meter square out to ranges of 220 to 240 km, tracking 50 to 60 targets simultaneously and guiding 10 to 12 aircraft through secure data link. The A-50 is widely associated with new generation Russian fighters like the MiG-29 and Su-27 which it normally controls. At the same time however, actual operations remain limited to supporting defensive fighter operations. As long as Russian defence posture continues to be centered on homeland defence and sees no need to play any role outside its borders this is unlikely to change.

India and AEW

India initially took the indigenous route to get an AEW system. DRDO’s Center for Airborne Systems (CABS) started work in July 1985 under project ‘Guardian’ later renamed ‘Airawat’. Termed as an ASP or ‘Airborne Surveillance Platform’ it involved fitting roto-dome based radar into an HS-748 Avro medium transporter. It first flew on November 5, 1990. Development continued throughout the decade by the ERDE (Electronics and radar Development Establishment) and it even made an appearance at aero India Air show in 1996 and 1998. However, the entire project came to an abrupt end on 11th January 1999 when the aircraft operating out of INS Rajali naval air station crashed near Arkonam in Tamil Nadu.

In August 2001 India turned to Israel after US gave an informal nod to go ahead with the supply of Phalcon AEW system. The programme involves mating the IAI/ELTA Phalcon AEW system with Russian supplied Il-76 airframe. Phalcon induction is poised to take IAF electronic surveillance capabilities to a new level. The system itself packages, Elta EL/2075 solid state Phased-array radar with sophisticated ESM/ELINT, IFF and CSM/COMINT system. Data gathered by all the sensors are continuously fused together to form a comprehensive electronic picture that greatly increase the scope of threat detection and classification. In line with the latest trend the EL/2075 is electronically steered beam radar, which has many advantages compared to a mechanically scanning unit, chiefly less aerodynamic limitations on the airframe, better performance against high maneuvering targets and a faster reaction time (track initiation is achieved in 2 to 4 seconds as compared to 20 to 40 seconds with roto-dome radar). Apart from providing the normal control duties, the Phalcon also doubles up as an ELINT and COMINT aircraft in its own right, negating the need to operate specialized aircrafts for each requirement. Thus the scope of AEW platforms is expanding worldwide to include SIGINT operations to monitor UHF, VHF and HF transmissions. This trend is expected to continue as such platforms are being increasingly used to target irregular terrorist outfits.

Indian Navy meanwhile has characteristically taken the lead in actually operationalising an AEW system when it started inducting the Ka-31 (NATO: Helix) helicopters in April 2003. Till now a total fleet of 9 choppers have been inducted into the INAS 339 Falcons squadron. Their deployment will spread across the aircraft carriers Viraat and the upcoming Vikramaditya (ex Gorshkov), the three Talwaar class frigates and the three Project 17 frigates now in the process of being fitted out at MDL. As part of carrier air groups they will work with MiG-29Ks to carry out fleet air defence missions while missile armed frigates would also use them for over the horizon targeting duties for their SSMs. The Ka-31 is expected to form the crucial back bone of emerging network centric operational doctrine of IN. To fulfill such a wide variety of roles it relies on an electronic suite centered on the E-801M Oko (“Eye”) mechanically scanned early warning radar. The 6m² radar antenna is stowed flat against the underside of the fuselage until deployed, when it folds out and rotates around 6rpm to achieve 360° azimuthal coverage. A surveillance range of 150km against a fighter sized target and 100 to 200 km against a surface ship is claimed, with the ability to track 40 targets simultaneously. IN seems to be satisfied with the abilities of the chopper and has made plans to include it in air group of the future ADS under construction at Cochin SY. While it’s certainly not comparable with fixed wing AEW platforms like the E-2, particularly lacking secure data link capability, its ideal for the smaller carriers India plans to acquire and build.

In August 2005 the Ministry of Defence reported to the Rajya Sabha about the revival of the indigenous AWACS programme. An amount of Rs.1800cr. was sanctioned for the same to the DRDO in October 2004. The whole programme is to be managed and fabricated by the CABS which expect initiation of testing by 2008 for service entry in 2010. The most likely platform could be the Brazilian Embraer EMB-145 a derivative of the Embraer ERJ-145 regional/business jet. EMB-145 AEW & CS aircraft is already in operation with the air forces of Brazil and Greece packing an Ericsson ERIEYE active, phased array pulse-Doppler radar. ERIEYE has a fixed, dual-sided and electronically scanned antenna mounted on top of the fuselage for 360° detection and tracking of air and sea targets over a typical range of 350km. The Indian system could have the ERIEYE or its local derivative.

Far more challenging would be the actual assimilation of AEW capabilities in the overall air operations. Indian military planners would have to work from the scratch, having almost no previous exposure to AEW operations. IAF has had the opportunity to fly with E-3 during Exercise Garuda II in June 2005 and Cope India 2005 in November, and would no doubt capitalize on the experience to develop its own AWACS tactics. Coming up with sound AWACS tactics is not just a luxury and will prove vital for conduct of successful fighter operations in future. This will hold truer as the proliferation of advanced fighter and all aspect BVR AAMs in neighborhood continues. With the advent of long range radar guided and all aspect IR AAM on potentially hostile fighters such as F-16 and Su-30MKK, odds would even with latest IAF fighters/AAM combinations. The potential impact of such fighter/missile combination was first evaluated by USAF in a series of tests known as AIMVAL/ACEVAL in late 70s. Small and cheap F-5E and A-4 armed with modern missiles were pitted against F-14 and F-15 and without the need to maneuver in the six o’clock position the small fighters scored an even no. of kills. It was an indication of onset of new highly lethal fighter operations. The only way to tackle such an adversary would be to use better situational awareness to ‘splash’ it at long ranges with the latest BVR AAMs like the R-77. Presence of an AEW in the loop would ensure that threats are identified much further out and dealt with faster. An IAF AEW platform flying more than 100 km inside Indian Territory could still cover about 600kms of enemy airspace carrying out surveillance of enemy aircraft and signal traffic. Future upgrades would surely include capabilities similar to the UK’s Astor Sentinel airborne stand off ground surveillance radar aircraft and the USAF J-STARS. Thus the scope of AEW missions is set to expand into true intelligence gathering platform working independently or in tandem with other airborne assets such as UAV and feeding near real-time data to air and ground commanders. This would require a whole new approach towards offensive and defensive fighter operations.






  5. Jane’s Fighter Combat in the Jet Age, By David C. Isby, Harper Collins 1997

(Shashank Sinha may be contacted at

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