A short history of AWACS
Since at least the Vietnam War, an increasingly critical element of air combat has been the radar early warning system. As air combat evolved, engagement distances grew larger, and thus the necessity of accurate radar returns and warnings became just as important as sharp eyes. Today, radars and warning receivers are arguably the most important tools in air combat; great radars potentially reveal the most advanced stealth aircraft, and warning sensors alert the pilots to threats they cannot visually identify – you cannot succeed nor survive in the modern battlespace without these systems.
The ultimate radar package comes in the form of the Airborne Early Warning and Control aircraft, or AEWs. Often overlooked by the public, AEW crews often play a critical role in the outcome of air engagements, assisting pilots in the same way as ground controllers once did. Today, we look back at the history of AEW aircraft - or AWACS as people often refer to them - all the way up to our own RAAF’s E-7 Wedgetail, arguably the most advanced platform on the market today.
EARLY HISTORY
As a side note, before starting, we will use the term AWACS to refer to some of these platforms, however technically the designation of AWACS refers to the multifunction suite installed on the E-3 Sentry. Strictly speaking these airborne platforms are simply AEWs, or Airborne Early Warning systems. However, for the sake of relatability and ease of understanding, we will use the term AWACS more broadly, as this is how the phrase is increasingly used today, even by pilots.
Since the introduction of radars, pilots have had to rely on a mixture of onboard radar and early warning systems, they also had to balance this with their own intuition and situational awareness. Ground radars offered many advantages over this, as those on the ground could effectively act as another set of eyes for the pilot, improving overall situational awareness. Putting this sort of technology into the air, however, would take early warning systems to the next level.
The key advantages of having what would essentially be a flying radar, would be range and mobility. Radars on the ground were either fixed or had to be towed around on trucks. At sea, it was a similar situation with the Navy’s Combat Information Centres on ships; they are good, but obviously slow moving and close to sea level due to the fact that they were… well, fixed on a ship.
An airborne system – flying at high altitudes - would be able to see far beyond any ground or ship radars. Low flying targets would be easier to pick up, and the obstruction of terrain would only be a serious issue at distances quite far away. Flying at altitude, they could move quickly to wherever they were needed, and crucially - thanks to their extended radar range - they would be far less vulnerable to counterattack than ground-based radar systems.
In World War 2, the first rumblings of this concept would emerge. In the 1930s, interest in radar was a big deal. As several falling outs between Germany and the UK led to increased tensions during this period, increased attention was given to the possibilities of using radio waves and radar for various tasks. At one point in the mid 30s, rumours circulated amongst the public that the Germans had developed radar death ray weapons that they would use in an armed conflict. British experts responded, saying this was probably false, and that the real benefit lay in aircraft and ship detection.
From 1936 to 1938, the British would develop the first early warning radar system, known as Chain Home. This ground-based system proved beyond any doubt that radar, as a means of tracking aircraft, was going to play a big role in the future.
By the time of the Second World War, proposals had been drawn up for an aircraft mounted radar system by British engineers. Fitting a Vickers Wellington with a rotating antenna array, they tested this aircraft to detect both German boats and aircraft sent out to attack shipping. Refinements were made, and by late 1944 an improved Wellington radar system became what we would call an airborne early warning and control aircraft, locating and tracking German bombers and even V-1 bombs. Such information was relayed to fighters to execute an intercept.
The importance and development of radar technology accelerated throughout the war. Both sides had developed night fighters with antenna systems to locate aircraft in the dark. The British had also developed an early form of chaff - known as Window - which they used to both throw off night fighters, and to disorientate ground radars when bombing German cities.
In late 1944, the US started to develop their own airborne radar system. Using an Avenger, the Navy began testing a variety of radar concepts under Operation Cadillac. One test found that at altitude, one such radar could detect targets up to 160 kilometres away.
The US saw the great potential of airborne radar and began in earnest to develop such systems. The vision was to have a large aircraft, with space for a crew to operate the radar and communicate what they see.
In 1949, the first such aircraft would take flight. Using the Lockheed Super Constellation as a platform, the first official AWACS went into production. Initially referred to as the PO-1W, it would hold a crew of 18, and use the AN/APS-45 and AN/APS-20 radars. Over the decades to come the aircraft would go through numerous upgrades and prove itself as a valuable air asset.
Interestingly, at the same time the Navy had also begun using blimps as airborne early warning systems, known as N-class ships, although these would be retired in the early 1960s.
VIETNAM WAR
By the time of the Vietnam War, air combat had changed significantly. Onboard radars were becoming essential, and missiles like the Sparrow were increasing the range of engagement. The PO-1W had been redesigned to become the Lockheed EC-121 Warning Star, a successful production platform that had operated since the mid-50s in numerous variations. These aircraft were used extensively over Vietnam in support of Operation Rolling Thunder and Operation Linebacker one and two.
By 1965, the Soviets were also operating AWACS - the Tupolev Tu-126 (NATO reporting name as ‘Moss’). Like the Warning Star, it was based on a commercial airliner, the Tu-114, and accommodated a crew of 12 to operate the equipment.
In the US, Grumman had developed its purpose-built airborne early warning platform in the mid 50s, the E-1 Tracer, and was in service by 1960. This aircraft was based on Grumman’s C-1 carrier transport aircraft and featured the new AN/APS-82 radar. This new system featured an airborne moving target indicator, which would identify moving targets and declutter static ground objects or ocean surface from the image. With a crew of just 4, it was significantly smaller than the Warning Star and was carrier based.
Even by the time of its introduction the military were concerned the aircraft would soon be obsolete. However, Grumman had already been working on yet another AWACS design - the E-2 Hawkeye. Featuring a crew of 5, it was still carrier-capable, and integrated the new APS-125 radar. First flying in 1960 - the same year the E-1 entered service - this new design proved superior and would itself enter service in 1964 with the US Navy as the E-2A. The Hawkeye did, however, suffer serious avionics problems due to inadequate ventilation for the systems on board and the fleet was grounded at one time. The upgraded E-2B addressed these issues and upgrade programs have continued for the type right up to today’s E-2D Advanced Hawkeye.
In Vietnam, the need for AWACS coverage was strategically important. The north Vietnamese primarily used ground controllers to vector pilots to target. When flying over North Vietnam on strike missions, this put US pilots at a disadvantage. The MiGs they were fighting either didn’t have radars, or had radars switched off until intercept. In contrast, US aircraft would rely on their own onboard radars to search for targets.
To complicate matters for the Americans, MiG pilots had been taught to fly low, which both obfuscated their visibility against the ground, and made them invisible to US radars due to terrain masking. The MiGs would simply fly according to the instructions given by ground controllers in the north.
The rollout of AWACS changed this dynamic. During the early years of the conflict, the readily available E-1 was used extensively. The E-1 crews would point out MiGs to US pilots, vector intercepts, and assist with coverage during Alpha strikes into north Vietnam. This was an instant game-changer, as these aircraft essentially gave pilots another set of eyes in the sky, and a much clearer battle space perspective. As these AWACS pushed further up the country, the less effective the MiGs terrain masking tactics became. Then, in 1965, the first E-2 Hawkeyes would arrive on deployment to Vietnam, amplifying the AWACS advantage in the war.
However, the primary AWACS (or at least the forerunner to the AWACS aircraft we know today) during the Vietnam conflict was the EC-121. The first Warning Stars had arrived very early in the conflict. They would quickly earn themselves a good reputation outsmarting the North Vietnamese.
During the opening days of Operation Rolling Thunder, Northern forces had been equipped with an advanced radar array that could track aircraft flying about 5000 feet practically anywhere in the country. Allied attempts to jam this radar system had failed. The EC-121 Warning Stars were called upon to level the playing field, and although their look down capabilities were limited and decluttering complex topography was difficult, the crews were highly adept. Having flown for years around Cuba tracking targets, they had their own manual method of decluttering radar images. The pilots would take the aircraft out off the coast of Hanoi, drop down to between 300 to 50 feet from the surface and bounce the look-down radar off the water surface, and detect aircraft at medium altitudes out to 150 miles. When paired with a EC-121 flying at 10,000 feet, a pair could patrol the airspace for about 100 miles into Vietnam, enough to cover the main MiG base just north of Hanoi.
As the war went on, both the EC-121 and E-2 would receive major updates, improving their radar capabilities. By the height of the war, some Warning Stars had received QRC-248 IFF interrogators, similar to the Combat Tree system on the F-4, which allowed far better locating and tracking of MiGs against the terrain.
By the 1970s, the airborne early warning method had proven indispensable for modern air combat. The Vietnam experience, and dramatic increases in air combat range, made the development of a new AWACS platform all the more urgent.
It was also during this time that the idea of an airborne command post became popular. In the US, this would result in several fixed wing or rotary wing platforms converted into flying command posts, such as the Lockheed EC-130, and later the Boeing E-6 and the Northrop Grumman E-8 Joint Surveillance Target Attack Radar System (or STARS).
The race was on for the US, UK, and Soviet Union to produce ever more sophisticated airborne early warning platforms. For the British, the answer to AWACS tasking would be the British Aerospace Nimrod AEW3. Based on the naval patrol aircraft of the same name, this new Nimrod platform would feature a massively overhauled array of systems and radars. Unfortunately, this platform would prove far too complex and expensive for long term use, and the British shelved it.
For the Soviets, the answer was the Beriev A-50. Based on the IL-76 transport, it would replace the Tu-126, and bring the Soviet air forces early warning abilities up to a new standard.
For the US, their answer would be the Boeing E-3 Sentry. Arguably the most recognisable airborne early warning aircraft, the E-3 emerged in 1977, a few years before either the Soviet or British designs, and revolutionised the abilities of US air assets. Based on the Boeing 707 and utilising a new pulse doppler radar from Westinghouse, the E-3 would host a crew of around 14, and would give unparalleled support for air assets, completely outclassing the EC-121.
It was with this platform that the term AWACS emerged, referring specifically to the onboard systems the aircraft used. The true effectiveness of such a platform for airborne warning as well as control was put to the test during Operation Desert Storm. Despite hundreds of coalition aircraft operating during the first night of Desert Storm, the E-3s managed to effectively control the airspace. After the conflict ended, it was reported that of the 41 air-to-air kills scored during the war, 38 were executed under E-3 guidance and assistance.
SITUATION TODAY
Today AWACS aircraft have become a crucial part of air combat – providing crucial battlespace awareness, lightening the workload for pilots, giving better coverage than ground radars, and facilitating networking of air, sea and ground assets.
Both the US and China increasingly shape aerial warfare doctrine around networked systems in the air, on the ground, and on the sea. AWACS aircraft integrate technology that allows increasingly precise datalink capabilities, a significant feature of modern warfare. As China appears to favour the American logic behind aerial warfare, it is likely we will see both the US and China adopt an ever more complex ability to integrate networked warning systems, using sensor information sharing, as well as artificial intelligence to crunch data and produce a more accurate picture of the battlespace.
In Russia, following the failure of centralised systems in the Soviet-Afghan war, the Russians had moved toward a less-networked and more individualist approach to air combat, in which more autonomy is given to different flights or groups. This is obviously more taxing on the individual pilot, who must always have a heightened sense of situational awareness. However, AWACS superior view of the battlespace and capacity for datalink and systems communications, will likely bring Russian doctrine for aerial warfare more in line with US and Chinese strategies.
Today, the US continues to operate the E-3 as the primary early warning system in the air, with the navy retaining the still highly valuable E-2 Hawkeye. In Russia, it remains the A-50, with plans to soon procure the new A-100. In China, this job is primarily handled by the KJ-500, as well as the KJ-2000. Japan also operates its own AEW platform known as the Boeing E-767, essentially a 767 airframe with internals from the E-3 Sentry.
However, the newest development has been the E-7 Wedgetail, produced for the Royal Australian Air Force.
E-7 WEDGETAIL
Based on the Boeing 737, the new Wedgetail has been developed primarily as an AEW platform for Australia. From outward appearances it is unique. Notably, the E-7 lacks the familiar circular radome of the E-3, but rather sports a fixed AESA radar antenna across the top of the fuselage.
The RAAF had been looking for a comprehensive airborne early warning platform for over 30 years. The long-awaited E-7 platform now serves the RAAF in a variety of roles beyond early warning and airborne command. The antenna array can be used in an electronic intelligence role which was first put to the test in a bid to find the wreck of Malyasia Airlines Flight 370 in 2014. The E-7 has also taken up a maritime patrol role and was deployed to the Middle East in the war against ISIS. During this conflict the E-7 flew 36 sorties - each lasting more than 12 hours - achieving a 100% success rate on each sortie. Long missions were completed with in-flight refuelling and crew rotations.
The Wedgetail now arguably leads the world in terms of airborne early warning capabilities, so much so that the US itself is now preparing to phase out its E-3 Sentry fleet and replace them with E-7s starting in 2027. Apart from the US, the UK and NATO are looking at acquiring Wedgetails, again replacing their E-3s, whilst both Turkey and South Korea operate the type.
We can only assume that the importance of AEW or AWACS aircraft will continue to grow. The implementation of drone technology and the increasing reliance on datalink systems essentially makes these aircraft the heart of an airborne fleet. Thanks to the E-7, our Australian Air Force currently has an edge technologically. The Wedgetail platform gives us the capability to easily patrol our extremely large landmass and oceans surrounding Australia. A unique challenge for Australia with a small population yet expansive landmass.
In collaboration with the KC-30, MQ-4C Triton, and Ghost Bat drone, the RAAF has the capacity to patrol the country and oceans effectively, and with a high resolution of data, considering the enormous distances involved.
The Wedgetails have been operated by number 2 squadron since 2010 and in future videos we will cover some of the combat missions and talk to some of the pilots and crew involved when supporting coalition forces in the Middle East as part of Operation Okra.