Analysis of Airborne Early Warning & Control platforms in the Indo-Pacific

By Mike Yeo

Airborne Early Warning and Control (AEW&C) aircraft are basically airborne radar picket systems designed to detect aircraft, ships, and vehicles at long ranges and perform command and control of the battlespace in an air engagement by directing fighter and attack aircraft strikes.

In addition, they can also perform command and control as well as battle management functions, making them a true battlefield force multiplier in a world where having information and the ability to use it is key to winning in battle.

One of the key indicators of the burgeoning military capabilities in the Indo-Pacific is the proliferation of such aircraft in the region.

In 2000 – just 20 years ago – only two countries operated such aircraft. Fast forward to today and no fewer than nine countries now operate them, with several already having replaced their first-generation types with improved platforms. In addition, several other countries in Australia’s neighbourhood have expressed an interest in introducing the capability into their own militaries.

AUSTRALIA

Following a recognition that it needed an AEW&C aircraft, Australia issued a Request for Proposals in 1996 for such a platform under Project AIT 5077 Wedgetail. A contract to supply four aircraft with three further options was issued to Boeing three years later, with Boeing proposing a solution based around a modified Boeing 737-700IGW fitted with a Northrop Grumman L-band Multi-role Electronically Scanned Array (MESA) radar.

The MESA radar is located on a dorsal fin on top of the fuselage with a ‘top hat’ that is designed for minimal aerodynamic effect. The radar is capable of simultaneous air and sea search, fighter control, and area search, with a maximum range of more than 600km (look-up mode). In addition, the radar antenna array also doubles as an ELINT array, with a maximum range of more than 850km at altitude.

Deliveries were to have begun in 2006, but the middle of that year saw Boeing admit that the program was behind schedule with problems in integrating radar and sensor computer systems expected to delay first deliveries until at least early 2009.

In the end, the first two aircraft were delivered in November 2009. These aircraft were both assembled by Boeing in Seattle, with the remaining aircraft assembled in Australia by Boeing at RAAF Amberley. By this time, the RAAF had decided to take up options for two further aircraft, bringing the total to six.

The Wedgetails serve with 2SQN at RAAF Williamtown, with a semi-permanent detachment stationed at RAAF Tindal in the Northern Territory.

Wedgetail achieved an Initial Operating Capability (IOC) in 2012, and Final Operating Capability (FOC) three years later. The first operational use of the Wedgetails was in March 2014 to provide air traffic control support to aircraft searching for missing Malaysia Airlines Flight MH370 off the Western Australia coast.

This was followed by participation in Operation OKRA against the Islamic State in Iraq and Syria that began in October 2014, flying missions as long as 17 hours directing airstrikes against the terror group’s targets in the Middle East.

The RAAF is already looking at upgrading its Wedgetail fleet, with $500-750 million flagged for Project AIR 5077 Phase 5A that will see Mode 5 IFF installed along with improvements to onboard encrypted datalinks, among others.

CHINA

China’s People’s Liberation Army Air Force (PLAAF) has transformed itself over the past two decades on the back of China’s transformation into a global economic powerhouse during the same period.

Gone are ‘knock-offs’ of obsolete Soviet-era MiGs that equipped the PLAAF in the 1990s, replaced by the products of an increasingly sophisticated domestic aerospace industry, albeit one which still depends upon a fair amount of Russian technology in the form of base aircraft designs and engines (along with accusations of acquiring technology via widespread theft and espionage).

Unsurprisingly, AEW&C aircraft are part of the modernisation plan. In 1996 China signed a deal with Israel’s IAI for the conversion of three of its Russian-built Ilyushin Il-76 fleet to AEW&C aircraft fitted with Israel’s PHALCON radar. The first aircraft had been converted but not delivered when US pressure put an end to the deal in 2000.

This forced China to develop its own KJ-200 and the larger KJ-2000 platform – KJ is the abbreviation of the Chinese word KongJing (directly translated as ‘Sky Warn’), the designation given to all AEW&C aircraft in Chinese service.

Fitted with a phased array radar arranged in a similar configuration to the later KJ-500, the first of four KJ-2000s entered service in 2005. Also based on the Il-76, the aircraft’s radar is claimed to have a maximum detection range of 470km.

The smaller KJ-200 is a Y-8 airframe carrying a dorsal ‘balance beam’ type radar outwardly similar to the Saab Erieye system. Development of the KJ-200 took place from 2001, although the crash of a prototype in 2006 which killed its test crew of 40 set the program back significantly.

The KJ-200 entered service in 2009, with aircraft assigned to the PLAAF’s 26th Special Missions Division at Wuxi west of Shanghai. At least 10 KJ-200s are in service, although the type has since been complemented with the new KJ-500. Based on the Y-9 airframe, the KJ-500 features a non-rotating circular radome which mounts an AESA radar in three separate arrays angled 120° to each other for 360° coverage. 

The KJ-500 also has a secondary electronic intelligence/signals intelligence (ELINT/SIGINT) function, with numerous fuselage fairings and an antenna array fitted. The first KJ-500 entered service with the PLAAF in late 2014, with the first examples joining the PLAAF’s 26th Special Missions Division.

Both the KJ-200 and KJ-500 are also assigned to the PLA Navy, with the service having deployed both types to operate over the South China Sea, operating from bases in China’s southern island of Hainan. China is also introducing inflight refuelling capability to the KJ-500, with an IFR probe mounted on top of the aircraft’s nose.

For China, one of the main hurdles to building more KJ-2000s has been the inability to secure more Il-76 airframes from Russia, with the PLAAF having to face the reality of balancing its relatively small fleet of aircraft across its growing airlift, tanking, and AEW&C requirements.

This is expected to be alleviated in the near future with the ongoing development of the indigenous Xi’an Y-20 airlifter. This will likely see China introduce more high-end jet-powered AEW&C aircraft in the future, although it is still unclear if these will be achieved by converting more Il-76s to KJ-2000s, or developing a new type based on the Y-20.

INDIA

Unlike China, India did not face the same kind of opposition from the US when it opted for the Israeli PHALCON radar. The two countries signed a contract in 2004 which saw Russia supply three Il-76s to Israel for conversion for India, equipped with the IAI EL/W-2090 radar.

The EL/W-2090 is an active phased array radar that is a development of the EL/M-2075 and EL/W-2085 radars. The three aircraft were delivered to the Indian Air Force between 2009 and 2011 but while India has repeatedly said it wants to acquire two more platforms, efforts to sign a contract have repeatedly failed since the mid-2010s.

Meanwhile, India’s Defence Research and Development Organisation (DRDO) has also developed an indigenous AEW&C aircraft to supplement the EL/W-2090s. The Embraer ERJ-145 regional airliner was selected as the platform with an indigenously-designed phased array radar mounted in a dorsal balance beam-type antenna.

The antenna has two radiating planar arrays assembled back-to-back inside the dorsal antenna, giving it 240° coverage. Known as Netra, and the first modified ERJ-145 made its maiden flight in December 2011, and the first two aircraft were delivered to the DRDO in 2012. An extensive test and certification process followed, resulting in the second Netra being handed over to the Indian Air Force only in 2019.

Indian defence sources have said that the third airframe was to remain with the DRDO, and it is unclear if a planned buy of up to 20 more aircraft will go ahead with India already seeking to develop a new large AEW&C aircraft based on the Airbus A330 that can also double as a tanker.

JAPAN

US ally Japan was a relatively early adopter of AEW&C aircraft, introducing the first of 13 Grumman E-2C Hawkeye turboprops in 1987. The decision was spurred by the defection of a Soviet MiG-25 which flew to Hakodate airport in northern Japan in 1976, catching Japan’s air defences totally by surprise when it landed at the small airport after a low-level flight over water. 

Assigned to the JASDF’s Airborne Early Warning Group (AEWG) at Misawa Airbase in northern Japan, the E-2C was originally the second choice for Japan which had preferred to acquire the more capable Boeing E-3 Sentry operated by the USAF. But it was unwilling to wait for production slots due to priority given to the USAF, UK and NATO production taking priority.

Japan revisited the possibility of acquiring the E-3 in the early 1990s. But with 707 production having ended, Boeing proposed a 767-based AEW&C platform fitted with the E-3’s system, and in 1993 and 1994 Japan agreed to procure four E-767s.

Based on the 767-200ER airframe, the E-767 carries the same Westinghouse AN/APY-2 passive electronically scanned array radar system as later model E-3s mounted in a similar rotating radar dome mounted on top of the aircraft’s fuselage.

The radar can track both maritime and airborne targets amid ground and sea clutter at ranges up to 320km at altitude. Japan’s four aircraft were delivered between 1998 and 1999, assigned to the AEWG’s 601 Hikotai at Hamamatsu in central Japan.

In November 2006, Boeing was awarded a $108 million contract to deliver Radar System Improvement Program (RSIP) kits to Japan’s E-767s, keeping them aligned with ongoing improvements to the USAF’s E-3 systems. Installation of the kits was completed December 2012.

The AEWG established a detachment at Okinawa’s Naha Airport in 2014, where the JASDF flew almost daily scrambles to investigate Chinese military aircraft flying in Japan’s air defence identification zone.

At the same time, increasing obsolescence issues with the JASDF’S E-2Cs saw Japan request the improved E-2D model. An initial request for three aircraft in 2015 was followed by nine more in 2018. The E-2D is fitted with a new Lockheed Martin AN/APY-9 ultrahigh-frequency-band radar housed in its dorsal rotodome, capable of detecting and tracking cruise missiles and low-observable aircraft.

While the initial Japanese aircraft are not fitted with the Cooperative Engagement Capability (CEC) integrated fire control capability like US Navy E-2Ds, it is almost certain its E-2Ds will receive this capability given Japan is going all-in with CEC for its newest AEGIS naval vessels,.

SINGAPORE

Singapore was the first country in south-east Asia to operate AEW&C aircraft when it acquired four E-2C Group 0 Hawkeyes from the US in 1987.

The Republic of Singapore Air Force (RSAF) operated the E-2C from land bases until 2015, replacing these with a similar number of Gulfstream/IAI G550 Conformal Airborne Early Warning (CAEW) systems ordered in 2007 and delivered from 2009.

The CAEW’s radar is the IAI-Elta EL/W-2085, an active phased array multi-band radar system developed from the single-band EL/M-2075 Phalcon system. The transmit/receive modules of the radar are mostly located in two huge conformal panels on the sides of the heavily-modified G550’s fuselage, with more found in oversize radomes in the nose and tail sections. The CAEWs are also equipped with ESM systems and have a limited SIGINT-gathering capability

The CAEWs are integrated into Singapore’s island-wide air defence network. While Singapore doesn’t share many of the details of its capabilities, it is likely the CAEWs have, or will receive, the Link-16 datalink to align with the integration of the system with its Boeing F-15SG Eagles and Lockheed-Martin F-16C/D fighters as part of ongoing upgrade programs.

Singapore’s CAEWs are operated by the RSAF’s 111 Sqn, based at Tengah in the west of the island. The aircraft are regular visitors to Australia, having taken part in the multinational air combat Pitch Black exercises as well as unilateral RSAF deployments to Darwin, the latter under a bilateral agreement between Australia and Singapore which allows the land-scarce nation to train in Australian airspace.

SOUTH KOREA

Technically still at war with its northern neighbour, South Korea’s military has spent decades training for and focused on stopping a potential invasion from the North.

As its economy grew into a global powerhouse, the conventional military balance has in recent decades tilted in South Korea’s favour and, despite maintaining a numerical advantage, North Korea’s military mainly operates obsolete equipment.

Instead, the main threat from the North comes from its nuclear arsenal via ballistic missiles and, as such, one of South Korea’s peacetime priorities has been to monitor North Korea’s ballistic missile program and activity. 

To that end, the Republic of Korea Air Force operates a number of reconnaissance, SIGINT and ELINT assets built around business jet airframes, as well as its primary AEW&C aircraft, the Boeing 737 AEW&C Peace Eye.

The type was selected in 2006 with Boeing to deliver four aircraft in 2012 under the Peace Eye program. The aircraft are essentially similar to Australia’s E-7A Wedgetails, and were chosen over the Israeli Gulfstream G550 CAEW that was later chosen by Singapore.

The first Peace Eye aircraft was built in Seattle and was delivered to Gimhae Air Base near Busan for acceptance testing in August 2011, with Korea Aerospace Industries (KAI) carrying out conversion work on the remaining three airframes. The last aircraft was delivered in August 2012.

South Korea approved the acquisition of more AEW&C aircraft in late June 2020. Although the actual type was not specified in the announcement, it appears likely additional Peace Eyes are favoured.

TAIWAN

Following the enactment of the Taiwan Relations Act by the US in the 1970s, the US is compelled to provide arms for Taiwan’s self-defence to fend off a potential Chinese invasion which the communist government has never ruled out as a means to reincorporate what it sees as a renegade province.

The arms provided to Taiwan include the E-2 Hawkeye. Taiwan first acquired four retired US Navy E-2B Hawkeyes in November 1995. These aircraft were refurbished and brought up to E-2C Group II standards with the AN/APS-145 radars, and designated the E-2T. In 1999, the US State Department approved the sale of two more E-2Cs to Taiwan, designated as E-2K, and these were delivered in 2006.

The E-2Ks were built to Hawkeye 2000 standards, with an avionics upgrade over the earlier E-2Ts along with a new mission computer and eight-bladed propellers. Taiwan subsequently opted to upgrade the E-2Ts to E-2K standard in 2008, and these were completed by 2013.

The E-2Ks serve with the RoCAF’s 6th Tactical Wing at Pintung Airbase in southern Taiwan where they act as a vital force multiplier for the RoCAF’s fleet of F-16s, F-5Es, indigenous AIDC F-CK-1 Ching-kuo fighters and ground-based air defence systems.

THAILAND

The kingdom of Thailand joined the AEW club in 2010, when a single Saab 340 fitted with an Erieye radar was delivered as part of a package that also included six Saab JAS-39C/D Gripen fighters and an additional Saab 340 transport.

This was followed by an additional package ordered in 2011 which included Gripens and one more 340 Erieye all of which were delivered in 2013.

Thailand also ordered the ground-based 9AIR C4I system that includes equipment for three ground-based sites in 2011. The system has been upgraded in recent years, and Thailand has also integrated its Saab 340 AEW aircraft, Gripens and upgraded F-5TH Tiger II fighters into the Saab-developed Thai Link-T datalink, allowing them to share a common battlespace picture.

The RTAF’s Saab 340 AEWs are currently based at Surat Thani in the southern end of the country alongside the Gripens.

Going forward, Thailand has shown interest in upgrading its 340s with improved C2 capabilities in the near term, turning them into true AEW&C platforms. The list of procurement priorities released by the RTAF in February 2020 also flagged the selection of a replacement for the type sometime between 2027 and 2029.

USA

The US military has based some AEW&C assets throughout the Indo-Pacific region with its forward-deployed forces. The USAF has assigned the Boeing E-3 Sentry to squadrons within its 3rd and 18th Wings based at Joint Base Elmendorf-Richardson in Alaska and Kadena Air Base on Okinawa respectively, with four aircraft in a squadron at each base.

The USAF’s E-3 Sentrys have undergone a series of incremental upgrades to maintain the systems’ relevance, including the joint US and NATO RSIP in the 1990s, the Dragon cockpit improvement program in 2009, and the ongoing Block 40/45 upgrade which replaces 1970s computer technology with an early 2000s standard. It includes a deployable ground system that receives, processes, and disseminates data.

The Block 40/45 upgrade program will bring the aircraft to the E-3G standard and, despite its age, there are no firm plans for the USAF to replace the type. Indeed, the USAF is considering future upgrades that will equip the E-3s with glass cockpits and new turbofan engines, the latter to improve the E-3s time on station and takeoff performance. 

Meanwhile, the US Navy also operates the E-2D Hawkeye, with five aircraft assigned to Carrier Air Wing 5 based in Iwakuni in Japan. The squadron was the first to convert to the E-2D and moved to Japan in 2017, where it regularly deploys on board the Japan-based forward-deployed aircraft carrier USS Ronald Reagan.

REGIONAL ASPIRATIONS

Elsewhere, both Indonesia and Malaysia have expressed an interest in acquiring AEW&C platforms, but neither appears close to making an acquisition any time soon.

Indonesia is stretched thin by requirements in a whole host of areas due to its need to adequately defend and archipelago of more than 17,000 islands stretched across thousands of kilometres, while Malaysia continues to suffer from a directionless defence acquisition process due to a severe budget crunch and a virtual freeze on its defence modernisation efforts, along with continued political instability.

If anything, the next buyer of an AEW&C platform in the Indo-Pacific might well be Vietnam, although it too has its own budget stresses and will likely face the issue of integrating a non-Russian bloc AEW&C aircraft into a military that is still dominated by Russian-built equipment.