In an age of digital networks and advanced weapon systems, the Airborne Early Warning and Control (AEW&C) aircraft is more important than ever. AEW&C is essentially a powerful radar and other sensors mounted in an aircraft so that, when flying at high altitudes, the airborne system possesses all the benefits of mobility and detection range
1st Jul 2010
In an age of digital networks and advanced weapon systems, the Airborne Early Warning and Control (AEW&C) aircraft is more important than ever. AEW&C is essentially a powerful radar and other sensors mounted in an aircraft so that, when flying at high altitudes, the airborne system possesses all the benefits of mobility and detection range. For example, an aircraft flying at 9,000m can typically offer radar coverage of a 312,000km² area. Able to distinguish hostile and friendly aircraft hundreds of kilometres away, AEW&C platforms provide commanders with an overall view of the battlefield to enhance airspace operations, surveillance, command and control (C2) and battle management. When networked with fighter aircraft, the AEW&C extend the sensors of the fighters and give them increased stealth since they do not need to employ their own radar systems. The AEW&C is certainly a true force-multiplier.
Previously commonly referred to as Airborne Warning and Control Systems (AWACS), AEW&C assets are passing through something of a generational transformation, as mechanically scanned radar systems are overtaken by Active Electronically Scanned Array (AESA) technology. Although AESA has been around for some time in ground-based equipment, it is now advanced and miniaturised enough to fit inside aircraft. To illustrate the advances being made, the current Phalcon AESA system from Israel Aerospace Industries (IAI) and ELTA Systems is said to be 2.5 times lighter, processes general-purpose data 200 times faster, and processes signals 3,000 times faster compared to the company’s 1995 system.
AEW&C systems are renowned for being expensive…as Australia and Boeing are finding out to their cost. However, Asian militaries are exploiting this new technology that can now be installed on smaller platforms, producing benefits in initial purchase and running costs. Two new systems are making AEW&C assets more affordable – the Saab Erieye and IAI/ELTA Phalcon - with several Asian countries obtaining this capability for the very first time.
The most widely employed AEW&C systems are the American E-3 Sentry and E-2 Hawkeye. The E-3 Sentry from Boeing Integrated Defense Systems has been serving since 1977, and is a mainstay of the United States Air Force (USAF). Based on a Boeing 707 airframe, the E-3 is easily identified by a 9.14m-diameter rotating radar dome (“rotodome”) mounted dorsally atop the fuselage. The AN/APY-2 pulse Doppler radar system is built by Northrop Grumman. Examples are found in Asia, with the USAF basing E-3 Sentries at Kadena Air Base on the Japanese island of Okinawa. These aircraft of the 961st Airborne Air Control Squadron (961 AACS) are able to monitor territories such as North Korea and parts of China.
The Japan Air Self-Defence Force (JASDF) flies four E-767 AEW&C aircraft, which is essentially E-3 technology fitted inside a more modern Boeing 767-200ER platform. The 767 was selected because production of Boeing 707s ceased in 1991, and all four JASDF planes entered service on 10 May 2000. Japan is the only country in the world to fly this Boeing 767 version, with one advantage of the 767 being 50% more floor space. Mission equipment includes the Joint Tactical Information Distribution System (JTIDS/Link 16), an IBM CC-2E central computer equivalent to that installed on the latest E-3 Block 30/35, and the AN/APY-2 radar system. The radar has a 360º view and 320km range. Boeing won a USD108 million Foreign Military Sales (FMS) contract in November 2006 to deliver a Radar System Improvement Programme (RSIP) to all four aircraft. This RSIP provides rewritten software, improved radar sensitivity, and more reliable computer multi-processors.
The other American system in widespread use is the E-2 Hawkeye, which originally entered US service in 1965. It has been regularly updated, with the latest in-service variant being the E-2C Hawkeye 2000. Designed especially for aircraft carrier use, the latest Hawkeye is equipped with APS-145 radar with a new mission computer, data-link system and Combat Information Centre (CIC). The US Navy (USN) has E-2C Hawkeyes from Carrier Airborne Early Warning Squadron 115 (VAW-115) aboard the USS George Washington, which is based at Yokosuka in Japan. As well as the E-767, Japan also flies 13 E-2C Hawkeye aircraft in the JASDF’s Airborne Early Warning Group (AEWG). The E-2C Hawkeyes, entering service in January 1987, are based at Misawa Air Base (in northern Honshu) while E-767s of 601st Squadron are at Hamamatsu Air Base (central Japan).
Taiwan, faced with a massive build-up of the People’s Liberation Army (PLA), operates six E-2C Hawkeyes in its 2nd Early Warning Squadron based at Pingtung. The arrival of four E-2T Hawkeyes for the Republic of China Air Force (ROCAF) in 1995 boosted the advance warning time of an attack from five to 25 minutes. Under an FMS contract, Northrop Grumman delivered two further E-2C Hawkeye 2000 AEW&C aircraft that were inducted into the ROCAF on 15 April 2006. Last year, Northrop Grumman was awarded a USD154.1 million contract to upgrade four older E-2T Hawkeyes to the latest 2000 configuration by June 2013. This upgrade will provide a JTIDS/Link 16 capability.
The rise of China and India
India is growing militarily as it envisages a strategic reach from the Persian Gulf to the Malacca Straits, but it also faces long-standing threats from neighbours Pakistan and China. Therefore, vital to its progression is acquisition of AEW&C assets. A major step forward occurred on 5 March 2004 when three AEW&C systems were ordered from IAI in a USD1.1 billion contract. The system ordered was the EL/M-2075 Phalcon radar based on Ilyushin Il-76 A-50 aircraft. The aircraft were purchased separately from Ilyushin in Russia for USD500 million before the AESA was added in Israel. The first completed aircraft was delivered to the Indian Air Force (IAF) on 25 May 2009, 18 months behind schedule because of delays in Il-76 airframe deliveries from Russia. The second aircraft was delivered in late March 2010, and India plans to acquire three more aircraft in the future too.
IAI’s Phalcon conformal array radar system negates the need for a rotodome. It was something of a surprise in 2003 when the USA announced it had no objection to India acquiring the Phalcon, which incorporated some American components. Phalcon is believed to be able to track 60 targets at ranges of up to 800km.
India is pursuing a second track for its AEW&C needs, this time domestically via the state-run Defence Research and Development Organisation (DRDO). Essentially a “mini-AWACS”, the Airavat Project is developing phased array radar atop three Embraer ERJ-145 aircraft ordered from Brazil in June 2008. This programme was revived after being cancelled in 1999 when a rotodome collapsed and caused a test aircraft to crash. A major stumbling block took place in 2006 when it was announced the prototype failed to meet IAF requirements allegedly due to a limited 300km radar range with coverage of just 240º. Again this project seemed to be an example of the DRDO’s overconfidence in its own abilities. The first unaltered Embraer aircraft should be delivered in 2011, with completion of flight testing and system integration optimistically scheduled for 2016.
India is also one of only four nations to field an AEW&C helicopter. The Indian Navy (IN) operates nine Kamov Ka-31 helicopters from Russia, and since 2003 they have flown from carriers, destroyers, frigates and from ashore. The Ka-31 has an E-801M Oko radar system that simultaneously tracks 20 targets out to a range of 150km for aircraft and 250km for surface ships. In India, Northrop Grumman has been jostling for position with its E-2D Advanced Hawkeye, which has the benefit of possessing a carrier-borne capability. After India snubbed an earlier offer for E-2 Hawkeyes, it was one of the first markets to be offered the more advanced E-2D variant. The IN is seeking up to six such carrier-borne aircraft, although none of its current aircraft carriers are equipped with the catapult needed for Hawkeyes to operate.
China wanted to acquire the Phalcon system from Israel as well, but the USA blocked this possibility and Israel was forced to cancel the programme in July 2000. As a direct result of this failure, China has developed two systems – the KJ-2000 based on an Il-76MD aircraft, and the smaller Shaanxi Y-8-based KJ-200. Four KJ-2000 (NATO reporting name Mainring) examples were commissioned in 2006-07, each equipped with Chinese-designed AESA radar designed by the Nanjing Research Institute of Electronic Technology. China claims the radar mounted in a non-rotating dome can track more targets than the Phalcon of the 1990s. These KJ-2000s are flown by the 26th Air Division of the PLA Air Force (PLAAF) in Zhejiang Province near Taiwan. Further KJ-2000 production is stalled due to a lack of Il-76 airframes because of the unacceptable prices Russia is asking for, but the need for aircraft has lessened somewhat with reductions in Taiwanese tensions. It is likely China will use an indigenous large transport design for future AEW&C aircraft, though operational entry of this new design is surely years away. Hence, one other theory being proffered is that China may retrofit AEW&C equipment onto a Comac C919 commercial aircraft in the future.
Because of vulnerabilities in relying on foreign sources, China developed the KJ-200 as a back-up. With a similar configuration to the KJ-2000, it is based on the Chinese copy of the An-12. The PLAAF has acknowledged the KJ-200 has not yet entered service and that it is still undergoing comprehensive testing. It was reported a KJ-200 crashed on 3 June 2006, killing 40 crew and technicians aboard, thus greatly setting back the programme. In 2009 there was little noticeable progress in operationally deploying these aircraft, one reason for this being their “political” involvement in the 60th anniversary parade. However, flight time is expected to rise in 2010. It is one thing to have a capable AEW&C asset, but it also necessary to have suitably outfitted aircraft that can benefit from the technology. In China’s case, since only limited numbers of fighters such as the J-10 and J-11B have digital data-links, voice communications with other aircraft remain the norm. One other weakness is that PLAAF data-links are not compatible with the HN900 data-link system of the PLA Navy (PLAN), meaning the two services have difficulty integrating. One other issue for China is its inexperience operating AEW&C aircraft, so there will be a steep learning curve in order to use this system to its full potential.
Pakistan ordered six Saab 2000 aircraft in early 2006 in a deal valued at USD1 billion. Four of these aircraft destined for the Pakistan Air Force (PAF) are to be fitted with the Swedish Erieye AEW system. The Saab aircraft have an endurance of nine hours at 9,000m, and are built to PAF specifications with five operator stations and four command stations. The radar has a 450km range, and it will be data-linked to the PAF’s C2 network and combat aircraft like the F-16. The first Saab 2000 aircraft was delivered in December 2009, while three more should arrive in 2010. In light of India’s problems in trying to indigenously produce AEW&C systems, Pakistan’s decision to opt for an off-the-shelf solution makes good sense. Cautious about becoming too dependent on the USA, Pakistan has pursued close military cooperation with China. Pakistan signed up for four Chinese ZDK-03 AEW&C aircraft in a deal worth USD278 million. The ZDK-03 is essentially a PAF version of the KJ-200, which incorporates Chinese AESA radar mounted in a Shaanxi Y-8F600 aircraft. The radar allegedly has a greater range than the Saab 2000 Erieye, and the first aircraft is expected in-country in late 2010. The deal includes shared research and development, and technology transfer.
Unsurprisingly, considering its advanced military and healthy economy, the first Southeast Asian country to gain AEW&C assets was Singapore. 111 Squadron of the Republic of Singapore Air Force (RSAF) has operated four E-2C Hawkeyes but these are being retired after arrival of new Gulfstream G550 AEW&C aircraft. Singapore ordered four G550 aircraft fitted with the EL/M-2075 Phalcon AESA radar in 2007. The aircraft were delivered in 2008 and all are expected to be fully operational this year. These aircraft have an endurance of nine hours at an altitude of 12,500m. While Singapore has not disclosed information about the radar, it is thought to have a similar capability to those delivered to the Israeli Air Force.
Thailand is another emerging country to seek AEW&C capabilities, and it will be the second Southeast Asian country to field one. The Royal Thai Air Force (RTAF) is set to take delivery of a Saab S100B Argus AEW&C aircraft with Erieye Side-Looking Airborne Radar (SLAR). The Erieye gives a 360° detection range of 350km against enemy fighters. The Saab aircraft were ordered as part of a package involving the Saab JAS 39 Gripen fighter. The Saab S100B is expected in Thailand in 2012, as well as an accompanying Saab 340 for training purposes. Phase 2 of the RTAF procurement would have seen Thailand order a second Saab AEW&C aircraft but, as part of reordered priorities necessitated by budget constraints, the new government has decided against it for now.
Australia, along with Turkey and South Korea, opted for an AEW&C system based on the Boeing 737. Under Project Wedgetail, the Royal Australian Air Force (RAAF) is set to receive four Boeing 737-700 aircraft fitted with a “top hat” Multirole Electronically Scanned Array (MESA) radar system from Northrop Grumman. However, since the order was registered a decade ago, the project has struck severe turbulence and delays now extend more than four years. There have been ongoing problems integrating the radar and electronic support measure (ESM) systems. Australia accepted the first two Wedgetails in May 2010, though presently they are only fit for training purposes by No.2 Squadron. Australia has exercised an option for two additional aircraft too. Once the Wedgetail system is successfully integrated, Boeing will be able to offer a product that could attract existing E-2 Hawkeye customers.
South Korea will hopefully be able to leverage lessons learnt from Australia’s woes. The Republic of Korea Air Force (ROKAF) will eventually take delivery of four aircraft with the culmination of its prolonged USD1.6 billion E-X AEW&C programme. The Boeing “Peace Eye” was declared the winner on 7 November 2006 after the IAI/ELTA Gulfstream G550 was eliminated. The first Boeing 737 was delivered to South Korea in February this year, and it should be ready for final handover next year after modifications by Korea Aerospace Industries (KAI). The Peace Eye AEW&C features Northrop Grumman’s L-band MESA radar. All four assets are expected to be delivered by 2012. Instead of relying on US resources, South Korea wishes to independently collect its own intelligence, surveillance and reconnaissance (ISR) data, especially as OPCON transfer from the USA is scheduled to occur in 2012. South Korea plans to employ its AEW&C aircraft in a new tactical reconnaissance wing to be set up by 2012.