Asian Airborne Early Warning Programmes

In any conflict environment it is essential to know what is happening in the air. Ground radars are able to provide a good picture, but having an airborne radar that can move from place to place is exponentially better. During the Cold War, airborne warning and control system (AWACS) aircraft like the E-3 Sentry were largely superpower luxuries, but in the last 15 years a variety of smaller, cheaper and equally effective aircraft have come onto the market, allowing both first world and third world countries to equip their air forces with these vital force multipliers.

17th Nov 2011


 Surveillance

 Asian Airborne Early Warning Programmes

Byline: Guy Martin / Johannesburg

In any conflict environment it is essential to know what is happening in the air. Ground radars are able to provide a good picture, but having an airborne radar that can move from place to place is exponentially better. During the Cold War, airborne warning and control system (AWACS) aircraft like the E-3 Sentry were largely superpower luxuries, but in the last 15 years a variety of smaller, cheaper and equally effective aircraft have come onto the market, allowing both first world and third world countries to equip their air forces with these vital force multipliers.

Asian nations in particular have quickly adopted these specialised aircraft and several countries, notably Thailand and South Korea, are gaining an airborne early warning and control capability for the first time. Meanwhile, regional tensions between India, China and Pakistan are fuelling competitive acquisitions in that region and encouraging the development of local airborne early warning and control (AEW&C) technology.


India

In April 2000 Russia sent two Beriev A-50 ‘Mainstay’ AEW&C aircraft to India, where they were used by the Indian Air Force (IAF) to evaluate the type and monitor Pakistani activity across the border. The IAF subsequently purchased the A-50 airframe with the Israel Aerospace Industries (IAI)/Elta Phalcon radar. The latter utilises an active electronically scanned array (AESA) L-band (D-band) Elta EL/M-2075 radar with a range of 380 to 400 km (235 to 250 miles) and the ability to track around 60 to 100 targets simultaneously.

On March 5, 2004, the Indian Ministry of Defence agreed to purchase three A-50EI systems at a total cost of US$1.5 billion. Three radar antennas are mounted in a non-rotating radome above an Ilyushin Il-76 transport, powered by Aviadvigatel PS-90 engines developing (16 000 kg/35 300 lb of thrust each). Each aircraft has a crew of 18.

Deliveries were two years late, taking place in May 2009, March 2010 and December 2010 (although actual deliveries to India, rather than Israel, came months later). Nevertheless, India is currently negotiating with IAI to purchase another two A-50EI systems and the Indian ministry of defence is studying an US$800 million draft contract, which it is expected to sign soon.

India in the 1980s attempted to develop its own AEW&C system under Project Guardian/Airawat. A prototype flew in 1990, but the project was halted in January 1999 when the Hawker Siddeley HS-748 testbed aircraft crashed, killing several important scientists and engineers. However, in October 2004 approval was given for a new Rs 1800 crore (US$398 million) indigenous airborne early warning (AEW) project. In June 2008 India signed a US$250 million deal with Embraer for three EMB-145s. These will have active electronically scanned array radars (Active Array Antenna Units) built locally by the Defence Research & Development Organisation’s (DRDO’s) Centre for Airborne Systems (CABS). The S band (E-F band) active electronically scanned array radar should have a range of 250-375 km (155-230 miles) with 240 degrees of coverage.

Embraer handed over the first EMB-145 at its factory in Brazil on February 21 and will deliver the remaining two aircraft in 2012 and 2013. The EMB-145 will become operational with the IAF in two to three years time once testing and certification has been achieved, long past the originally scheduled date of 2011.

The Indian Air Force is said to be looking into acquiring another 20 airborne early warning platforms and in November last year the DRDO said it had received the go-ahead for developing another six AEW&C systems for delivery from 2015.

The Indian Navy is one of a small handful of organisations operating AEW helicopters. In August 1999 the Navy ordered four Kamov Ka-31s, which entered service in April 2003. Another batch of five, ordered in February 2001, was delivered in 2005. Total cost of the nine helicopters is estimated to be around US$200 million. Ka-31s are deployed from the INS Viraat aircraft carrier and three Talwar class guided missile frigates, as well as the Navy’s shore bases.

The Ka-31 features the E-801M Oko (Eye) pulse-Doppler phased array early warning radar. Typical range against a surface ship is more than 100-200 km (60-125 miles) while the radar can monitor fighter sized aircraft at up to 150 km (95 miles). The radar can track 20-40 targets simultaneously, making it an important part of navy operations since surface vessels’ radar coverage is limited by the curvature of the earth.

However, the Ka-31 has not lived up to the Indian Navy’s expectations, with a short loiter time (2.5 hours) and technical defects. This has prompted the Navy to contemplate purchasing fixed wing AEW aircraft for its future aircraft carriers - in May last year India’s navy released a request for information (RFI) for four carrier-based AEW&C aircraft. Northrop Grumman responded by proposing its E-2D Advanced Hawkeye, which was cleared for export by the United States government. After receiving a Request for Information for its E-2D, Northrop Grumman is confident of a Request for Proposal by the end of the year.


Pakistan

India’s neighbour and rival Pakistan is also hurriedly acquiring AEW&C aircraft, after trying to do so for more than 25 years. In June 2006 Pakistan signed a deal with Saab for four Erieye radar systems mounted on Saab 2000 turboprops, which are larger and more powerful versions of the Saab 340. The Saab Microwave Systems PS-890 Erieye multi-mode pulse-Doppler radar can detect and track targets over sea and land at ranges of up to 450 km (280 miles) and amidst jamming, heavy radar clutter or low target altitudes operates out to 350 km (220 miles).

The Saab 2000 Erieye aircraft feature five operator stations and four command stations. They are equipped with the HES-21 electronic warfare suite that includes laser, radar and missile approach warning sensors and countermeasures dispensers. Endurance is nearly ten hours. The first Saab 2000 arrived in Pakistan in December 2009.

In a further sign of its strong relationship with China, Pakistan will receive four Shaanxi ZDK-03 AEW&C aircraft from its northern neighbour at the end of this year. The aircraft are based on the Shaanxi Y-8/KJ-200 AEW&C turboprop aircraft but are designed to Pakistan’s specifications. In 2008 Pakistan signed a US$278 million contract with Beijing for the four aircraft. China rolled out the first ZDK-03 on November 13 last year, with deliveries expected to begin in November this year and conclude by 2014. The aircraft feature AESA radars and open architecture electronics that allow for future improvements.


China

The ZDK-03 is the result of China’s numerous AEW&C experiments. Since the 1960s China has expressed interest in acquiring an AEW&C capability, and tested an AEW rotordome aboard a Tupolev Tu-4 (Boeing B-29 Stratofortress). In May 1997 China acquired an Ilyushin Il-76 to use as AEW platform with the Phalcon system and planned to procure three more. The first Il-76 was modified by Beriev and delivered to Israel in October 1999 for the installation of the Phalcon system, but the deal was vetoed by the United States and cancelled in July 2000, dealing a massive blow to China’s AEW&C ambitions.

China was forced to pursue its AEW ambitions independently. After the A-50/Il-76 had been stripped of equipment it was in 2002 allocated to the China Flight Test Establishment and used as the prototype for China’s indigenous AEW programme. The resulting KJ-2000 aircraft, first flown on November 11, 2003, was fitted with a dorsal radome that is assumed to house three fixed active electronically scanned antenna arrays built by the Nanjing Research Institute of Electronic Technology (‘14th Institute’). Apart from the prototype, four KJ-2000s are operational, having entered service in 2006-2007. They serve with the 26th Air Division of the People’s Liberation Army Air Force in Zhejiang Province near the Taiwan Strait.

China has performed a lot of experimentation with the smaller Shaanxi Y-8 (Antonov An-12) platform, which was modified with a circular rotodome above the fuselage, but it seems that development of this variant has been sidelined by phased array versions of the Y-8 featuring ‘balance beam’ or ‘plank’ radar arrays.

At least one Y-8 was modified with the BAE Systems (Racal) Skymaster AEW radar, six of which were ordered for US$66 million in 1996. The radar, installed in a bulbous nose, can scan 360 degrees out to more than 370 km (230 miles), although range is only 185 km (115 miles) in high clutter/sea state conditions. A Skymaster modified Y-8 flew in November 1998 and was observed in People’s Liberation Army Navy (PLAN) exercises. At least two are reportedly deployed near Shanghai and used by the PLAN for maritime patrol.

China developed a smaller AEW&C aircraft out of the Y-8 to complement the larger KJ-2000, with the aim of operating the smaller KJ-200 as part of a joint AEW network. The KJ-200 features a rectangular antenna above its fuselage, similar to that of Embraer’s EMB-145. Unfortunately for China’s AEW&C ambitions, the project suffered a major setback on June 3, 2006, when the KJ-200 prototype crashed, killing all 40 on board, including key programme technical staff. Nevertheless, the KJ-200 project has gone forward and at least four KJ-200s have been built so far. At least one has been seen in PLAN colours.

China also requires AEW aircraft for its first operational aircraft carrier, the ex-Soviet Varyag, as well as the two other aircraft carriers it is believed to be building. To this end China bought nine Ka-31s (and nine Ka-28s) from Russia. It seems that the first two Ka-31s were delivered late last year and by the end of January five had been delivered, with the remaining four following by mid-year.

The PLAN may also have developed an indigenous AEW helicopter - in October 2009 photos emerged of a CHAIG Z-8 with a retractable radar antenna attached to the rear loading ramp door. The radar-equipped Z-8, in PLANAF colours, was observed landing on the Varyag before its maiden voyage in August and, like the Ka-31, may be a stop-gap aircraft until China fields its own fixed wing carrier-based AEW aircraft. The Varyag will enter service in late 2012 and will primarily be used for training, giving the PLAN a valuable opportunity to prepare its AEW aircraft for China’s indigenously built aircraft carriers.


Japan

Japan was one of the first export customers for the Northrop Grumman E-2 Hawkeye (coming second after Israel). It received eight Group 0 Hawkeyes between 1982 and 1985 and five Group II aircraft in 1992-1993. E-2s are flown by the Air Warning Surveillance Unit based at Misawa Air Base. Their AN/APS-145 radar can detect large targets up to 550 km (340 miles) away, or a 3 sq m (30 sq ft) target at 330 km (210 miles). The radar can track 20 000 targets simultaneously while controlling the interception of 40.

The Japan Air Self Defence Force (JASDF) planned to upgrade its Hawkeyes to Group II standard but instead upgraded them all to Hawkeye 2000 standard. These aircraft feature an updated mission computer, inertial navigation system, workstations and Co-Operative Engagement Capability (CEC) datalink that allows multiple platforms to view the same information. The first modified E-2C was flown in July 2004 and delivered in early 2005. Modification work, lasting around five years, was carried out in Japan with Northrop Grumman supplying the necessary kits.

In order to strengthen its AEW component and complement its smaller Hawkeyes, the JASDF in December 1992 decided to order four E-767s from Boeing. The order for the first two aircraft went through in November 1993. Japan’s AWACS mount the Boeing E-3 Sentry’s AN/APY-2 radar system on the 767 airframe, as production of the E-3’s 707 airframe ended in 1991. The E-767 AWACS features a large 9.14 m (30 ft) diameter rotodome above the fuselage housing the Northrop Grumman radar, which is an S-band (E-F band) system giving 360-degree coverage out to a range of more than 375 km (250 miles). It can detect and track air and sea targets at the same time and is able to pick up low-flying targets amidst ground clutter and can also pick up targets in the stratosphere.

The 767 AWACS is in many respects far superior to the 707-based E-3. The wide-body airframe gives 50% more space and almost twice the volume of the 707 and only requires two, not four, flight crew. However, the E-767 is very expensive, something that has put off at least one potential buyer.

In March 1998 Japan’s first two E-767s were delivered to the Japanese Air Self Defence Force at Hamamatsu Air Base for a year of testing, and the final aircraft were delivered in 1999. They entered service with 601st Squadron on May 10, 2000 (they now serve with Air Warning Control Squaron at Hamamatsu). Together with the Hawkeyes, they work together to augment Japan’s Basic Air Defence Ground Environment, which consists of radar stations and air defence centres located throughout the country.

They have recently received the Radar System Improvement Programme (RISP) upgrade that improves the AN/APY-2’s effectiveness against cruise missiles and aircraft. The upgrade also features better electronic counter-countermeasures, improved reliability/maintainability and new pulse compressed waveforms.


Singapore

In 1987 Singapore received four AN/APS-138-equipped Group 0 E-2C Hawkeyes. They have received numerous upgrades throughout their lives and have many Hawkeye 2000 features such as a new mission computer, colour displays, GPS and updated cockpit.

In April 2007 Singapore announced it would replace these aircraft with four Gulfstream G550 Conformal Airborne Early Warning (CAEW) aircraft as part of the Republic of Singapore Air Force’s modernisation plans. IAI’s CAEW platform mounts a smaller derivative of the Phalcon called the EL/W-2085, which has two L-band (D-band) antennas at the sides of the aircraft and S-band (E-F-band) nose and tail antennas to give 360-degree coverage. Each of the six workstations is able to monitor aerial activity and perform command and control tasks. A jam-resistant satellite datalink provides voice, data and video communications.

The Elta EL/W-2085 system also includes electronic support measures, electronic intelligence and communications intelligence systems as well as an identification friend or foe system integrated with the radar. A comprehensive countermeasures suite includes a missile approach warning system, radar warning receivers, chaff and flare dispenser and directional infrared countermeasures.

For its size, the G550 CAEW is a high performance aircraft. It is able to fly at 1 084 km/h (673 mph), has a range of 12 500 km (7 770 miles) and an endurance of nine hours at 12 500 m (41 000 ft) altitude.

The first G550 was handed over to the Royal Singapore Air Force on February 19, 2009, and assigned to No 111 Squadron.


Taiwan

Another Asian Hawkeye operator is Taiwan, which ordered four E-2T Hawkeyes with AN/APS-145 radar in 1993, as part of a US$749 million contract. They were delivered in September 1995 and entered service that November. They are important assets in protecting Taiwan against sea or air attack from China across the Taiwan Strait. In July 1999 Taiwan also bought two Hawkeye 2000Es for approximately US$400 million. Designated E-2K locally, they entered service with the Republic of China Air Force’s 2nd Early Warning Squadron at Pingtung on April 15, 2006.

As with many other Hawkeye operators, Taiwan is keen to keep its aircraft up to date. In 2009 Northrop Grumman received a US$154.1 million contract via the US Navy to upgrade Taiwan’s six Hawkeyes to E-2C Hawkeye 2000 standard by June 2013. The contract involves modifying the two E-2Ks that already meet basic E-2C Hawkeye 2000 configuration. The other four aircraft will be modified from their E-2C Group II configuration and will receive JTIDS/Link 16 capability.


Australia

For many years Australia searched for a suitable airborne early warning aircraft under Project Wedgetail. In December 2000 the Royal Australian Air Force (RAAF) settled on Boeing’s 737 Wedgetail AEW&C aircraft and ordered four plus three options, at a cost of US$1.65 billion. In May 2004 Australia decided to buy another two aircraft, bringing the programme cost to US$3.9 billion.

The 737-700-based Wedgetail’s main feature is Northrop Grumman’s state-of-the-art L-band (D-band) Multirole Electronically Scanned Array (MESA) radar bolted onto the top aft fuselage in ‘top hat’ configuration. The radar provides coverage out to more than 400 km (250 miles) and can track several thousand sea and air targets simultaneously. MESA’s unique antenna design uses three different electronically scanned arrays to give 360 degree coverage. There are two side-looking arrays as well as the top-hat array that uses so-called ‘endfire’ techniques to steer the radar beam in front of and behind the aircraft. This allows for a relatively low-drag antenna. Radar operators can identify certain targets and sectors and then get the radar to scan them in greater detail.

An IFF system is combined with the main radar and has a range of more than 550 km (345 miles). Other avionics include Link 4A, Link 11 and JTIDS datalinks, as well as 11 HF/UHF/VHF radios. A comprehensive self-protection suite includes a directed infrared countermeasures system, plus chaff and flares.

The highly advanced radar and other electronics systems have experienced numerous problems and significantly delayed the introduction into service of Australia’s Wedgetails. During the development of the top hat antenna, problems were encountered and the antenna had to be redesigned, necessitating extra wind tunnel tests, thus causing further delays. Delays were also caused whilst the software was upgraded and improved.

A 2009-2010 Auditor General report stated the Wedegtail’s radar would not match specifications upon delivery and there were problems with many of the aircraft’s electronic systems, including the Electronic Support Measures (ESM) systems. Although most of the problems have been ironed out, the Wedgetail’s radar will not quite reach specifications.

Deliveries were originally scheduled for 2006, but the first two aircraft were only delivered to the RAAF on November 26, 2009, and were accepted on May 5, 2010. Boeing delivered four of six aircraft with some systems missing, meaning they had limited functionality and were mainly used for training purposes with No 2 Squadron at RAAF Base Williamtown. Boeing expects to deliver all six aircraft in full configuration by the end of the year - Australia’s Wedgetails are expected to achieve initial operating capability in December. Between October 17 and November 4, the aircraft took part in the Bersama Lima Five Power Defence Agreement exercise involving Malaysia, New Zealand, Singapore and the United Kingdom. Final acceptance of the first fully configured Wedgetail will take place in March 2012.


South Korea

In August 2006 South Korea selected the 737 AEW&C aircraft to fulfil the country’s E-X requirement for surveillance aircraft, to be delivered by 2012. The US$1.59 billion price tag for four Peace Eye aircraft also includes training and support. The first aircraft was delivered to Gimhae air base southeast of Seoul on August 1. It underwent flight testing before being accepted by the Republic of Korea Air Force on September 21 during a ceremony attended by the Republic of Korea Air Force and American and South Korean officials and industry partners. South Korea’s remaining three aircraft are being modified by Korea Aerospace Industries at its Sacheon facility for delivery next year.


Thailand

Thailand has become the most recent Asian nation to field an AEW&C aircraft and the first export customer for Saab’s S100B Argus. In February 2008 Thailand announced the procurement of 12 Saab Gripens, two former Swedish Air Force Saab 340 AEW&C aircraft, with Erieye radar, and one Saab 340 transport, worth a total of US$1.65 billion. Only half the order went through initially, but in August 2010 Thailand approved funding for the remaining six Gripens and the second AEW&C aircraft, signing a contract three months later. These aircraft will be delivered in 2013.

Thailand’s first Saab 340 AEW&C aircraft performed its maiden flight on November 13, 2009, and was handed over to the Royal Thai Air Force on November 13, 2010. On July 8 the Air Force declared its new air defence system, comprising its six Gripens and one Saab 340 Erieye, operational during a ceremony at its Wing 7 base in Surat Thani.


Russia

Russia began development of the Beriev A-50 ‘Mainstay’ AEW&C aircraft in the early 1970s as a replacement for the marginally effective turboprop-powered Tu-126 ‘Moss’. The resulting Il-76-based aircraft first flew on December 19, 1978, and entered Soviet Air Force service in 1984. 27 were built and 16 remain in service with the Russian Air Force’s 2457th Aviation Base for Combat Operation of Airborne Early Warning Aircraft at Ivanovo-Severnyi.

The A-50 mounts the Vega Shmel (Bumblebee) pulse-Doppler radar in a large rotodome above the fuselage. The Shmel radar and guidance systems are able to track between 50 and 60 targets and control 10 to 12 fighters simultaneously. The Shmel radar has fairly good look-down capability and is able to track small targets like cruise missiles against ground clutter. Look-down range is between 200 and 250 km (125 and 155 miles) while range against fighter-sized targets is 300 to 350 km (185 to 220 miles).

The A-50 is crewed by 15 people, including five flight crew. The A-50 has a comprehensive communications system that includes data-link, satellite communications and multiple radios that allow it to control fighters and download tactical information to ground stations and fighters automatically.

Russia recently begun receiving its first upgraded A-50U aircraft, which feature improved radar systems with better range and tracking capabilities, more powerful computers, digital avionics, LCD workstations, improved communications and navigation equipment and more fuel for greater range. Work on the upgrade began in September 2008 and the first aircraft was handed over to the Russian Air Force on October 31.

Russia plans to produce a new AEW&C platform in the next five years. In August, Russian air force chief Colonel General Alexander Zelin said he expected to receive the new A-100 aircraft within the next five years. This will be based on the Il-476 transport, powered by PS-90 engines. Unlike the A-50’s radar, the A-100 will have an AESA radar, capable of detecting and tracking both air and ground targets. Zelin said the Russian air force will have the Il-476 platform by 2013-14 and the A-100 by 2016.
 

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