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Dalnaya Radio-Lokacyonnovo Obnaruzhyeniya [DRLO]
Long-range Radio-Location and Control [DRLO]
Airborne Early Warning [AEW]
Airborne Warning and Control Systems (AWACS)

The primary way in which the Soviet Union sought to remedy the shortcomings of its ground-based air defense radars was to deploy large radars on aircraft. These aircraft, known as Airborne Early Warning [AEW] or Airborne Warning and Control Systems (AWACS), monitor enemy penetrators - AEW - and coordinate air defenses over a large area - AWACS.

One of the factors in the radar horizon formula is antenna height. The same aircraft operating at 3000 feet against an antenna height of 25,000 feet (in an Airborne Warning and Control, AWACs, type system) would have a radar detection horizon of over 250 miles.

The range of an AWACS is much greater than that of ground-based radars - over 200 miles to the horizon and over 400 miles to another aircraft at a high altitude. A line-of-sight radar standing 50 feet above the ground theoretically can detect at about 30 miles abomber flying at 300 feet above the ground. At greater distances, the bomber is hidden by theearth's curvature. The actual detection range might be less than the theoretical range because ofthe disruption or blocking of radar pulses by terrain features such as hills. The actual detectionrange might be greater than the theoretical range if the radar is located on a hill.

Countries possessing airborne look-down, shoot-down radars have a definite advantage in detecting low altitude attacks. These radars are usually pulsed doppler radars and capable of detecting moving targets in ground clutter. When airborne, the AWACS cannot be targeted in advance since its precise location is unknown.

AEW aircraft can make a decisive contribution to air operations, detecting hostile aircraft as soon as they take off, and managing air defense and counter-air operations. While one side vainly gropes in the dark, the side with AEW capability knows exactly where the enemy is -- and isn't -- can most efficiently direct friendly forces against the enemy's weak points, and maximize surprise. Well known American airborne early warning radar systems for manned aircraft are the AWACS and HAWKEYE, both of which employ specially designed airframes and are relatively expensive.

  1. The first indication of a Soviet AEW program was the 1968 release of a documentary film showing a transport-type aircraft which appeared to be carrying a radar dome. This first Soviet AWACS, the Moss, was relatively ineffective in tracking low-flying bombers and cruise missiles.
  2. The more recent Soviet AWACS, the Mainstay, is considered to be much more capable. The MAINSTAY airborne warning and control system (AWACS), deployed in the late 1980s, provided the Soviet Air Forces with a battle management capability for their new FLANKER and FULCRUM aircraft. An effective AWACS capability was essential for the Soviet drive for theater air superiority over NATO. Mainstay can detect remote threats and vector an interceptor such as the Flanker. Its mission is to detect low-flying aircraft and missiles and to help direct fighter operations. The Mainstays might patrol near the Soviet borders to track approaching U.S. bombers, providing the greatest possible reaction time.
  3. Two Naval AEW aircraft were developed but cancelled. The first was an AEW version of the Antonov An-72 twin-turbofan STOL transport, codenamed "Madcap" by NATO; this interesting design (the radar disc was mounted atop a forward-swept, V-shaped set of tail fins) was cancelled. Systems evidently affected by cutbacks included the Madcap airborne warning and control aircraft, which probably had been canceled by 1991. The official reason given was that a turboprop was more efficient for the AEW role than a jet The fact that Yakovlev is a Russian company while Antonov is Ukrainian probably had something to do with this.
  4. The second was Yakovlev's Yak-44, a twin turboprop rather similar to the Grumman E-2 Hawkeye. The Yak-44 was also in turn cancelled (although a revival has been considered).
  5. The Ka-31 Helix-B AEW version of the Kamov Ka-32 helicopter was developed on the basis of Ka-27 ship-borne coaxial helicopter.

The design of aircraft to carry radar equipment suitable for carrying out an airborne early warning (AEW) mission poses significant problems. One requirement for such a mission is provision of 360.degree. azimuthal radar coverage. This creates the need to install, in the aircraft, radar antenna arrays having substantial physical space requirements. One solution to this problem is to mount additional structures on a standard aircraft to accommodate the required radar equipment. The well-known addition of an external rotodome onto an aircraft is an exemplary implementation of such a solution. Use of a dorsal fin mounted on an aircraft to house antenna arrays is another known example of such a solution. The addition of such structures typically requires structural modification to the aircraft to accommodate the additional structure.

One obvious adverse affect of such additional structures is that the aircraft suffers aerodynamic drag penalties. As a result, the overall performance of the aircraft is limited. The drag penalties also serve to limit the flying range of the aircraft. This result is contrary to the AEW mission of the aircraft since it is desirable for the aircraft to travel significant distances from its base of operation and/or remain airborne for extended periods in order to scan over a large area. A further adverse effect of additional structures is that the aircraft becomes mission dedicated. That is, the aircraft serves no useful function other than to fly the AEW mission.

The utilization of integral radome-antenna structures, and particularly such types of structures which are rotatably mounted on aircraft and employed as so-called airborne early warning systems (AEW) is well-known in the technology, and has successfully found widespread applications in conjunction with military surveillance aircraft,, especially aircraft adapted to be launched from naval carriers. In various instances, as currently utilized in military aircraft, such radome-antenna structures are mounted positions so as to be superimposed above the fuselage of the aircraft, although conceivably also being suspendable from below the fuselage, and incorporate a depending shaft structure, generally hollow in nature, extending downwardly from the radome into the fuselage of the aircraft, and wherein the shaft is operatively connected to a suitable drive arrangement for simultaneously rotating the shaft about the longitudinal axis thereof and the radome-antenna structure at specified speeds of rotation.

Suitable couplings and slip ring assemblies may be provided in order to connect the antenna array contained in the radome to suitable stationary sources of electrical energy while, concurrently, enabling the pick-up of signals received by the antenna array and to transmit the signals to stationary signal processing component and/or display consoles which are located in the cabin of the aircraft. Moreover, a suitable cooling fluid may also be transmitted to the antenna components contained in the radome through the intermediary of the hollow shaft mounting and supporting the radome-antenna installation for rotation.

By 1975 the Soviets had an airborne surveillance system - a converted CLEAT transport which is known as the MOSS. It was, however, vastly inferior to the American AWACS, particularly in radar capability. In any event, the cost for the large numbers of aircraft required for contiguous surveillance coverage at all times across the vast expanse of the U.S.S.R. would probably make some types of operations infeasible. Thus US intelligence expected that they Soviets employ the SUAWACS force by flying patrols along the periphery of the U.S.S.R. Moreover, interceptor and SUAWACS basing constraints and the much longer border of the U.S.S.R. would virtually preclude a SUAWACS operation that would be as effective as the American AWACS in the CONUS air defense role. For example, a Soviet bomber force would be required to traverse the vast expanse of Canada before reaching the USA.

In addition, the numerous civilian and military bases across the Northern states are suitable for both AWACS and interceptor operations. The U.S.S.R. has no barrier of friendly territory protecting its northern approaches, its border is much longer, and basing suitable for SUAWACS/interceptor operations is not always available.

It should also be noted that the bomber penetration problem into the U.S.S.R. in a nuclear conflict is distinctly different from the tactical penetration of a theater of operations in a conventional conflict or Soviet penetration of the USA against an AWACS augmented air defense force. Tactical operations within a theater are characterized by relatively confined air space which would be under continual surveillance and one in which repeated penetrations are required. Moreover, the long-range radar of the AWACS would be able to track hostile aircraft virtually from take-off. Thus in the tactical scenario, avoiding detection by exploiting gaps in AWACS coverage is not possible.

The American bomber penetration problem would be characterized by avoidance of detection to the extent possible and rapid transit of surveillance zones to minimize exposure and probability of intercept when detection cannot be avoided. The US Air Force assumed that the SUAWACS would patrol in areas where interceptors could respond effectively in the event that bombers were detected. Thus, interceptor basing, range, and payload constraints limit the portion of the U.S.S.R. that are likely areas for SUAWACS patrols. The USAF would therefore pre-plan bomber penetration routes, where feasible, through areas not supportable by airborne interceptors, i.e., areas least likely for SUAWACS patrols. The USAF would plan the bomber penetration tactics to descent to low level outside the surveillance volume of the SUAWACS. Low level tactics would not prevent detection but would minimize the time under surveillance. Radar Homing and Warning (RHAW) equipment could detect the presence of a SUAWACS in sufficient time to permit the use of this tactic. It would also allow the bomber crew to determine the direction of movement of the SUAWACS and exploit temporary gaps in surveillance coverage inherent with patrol coverage as opposed to contiguous orbits.

ECM equipment would be employed judiciously by American bomber to prevent highlighting the location of the bomber. There would be times when the penetrating bomber would enter the surveillance volume of the SUAWACS when Soviet interceptors were available. In this Case, bomber ECM would force the SUAWACS to vector the interceptor out the resultant strobe or cause the SUAWACS to resort to strobe triangulation. In either case, time to intercept as well as the probability of detection and conver*\on of the interceptor would be degraded to some extent. Moreover, mutual supPort jamming by other penetrating aircraft could be used to further degrade the effectiveness of the SUAWACS/interceptor team.

However, the pricipal means of insuring continued American penetration after detection would result from the capability of the bomber to degrade the effectiveness of the interceptor's fire control system and radar guided missiles through a combination of ECM and maneuver. The Amerians assessed in the mid-1970s that the systems of the B-52 would be effective in this role; the defensive avionics, much smaller radar cross Section, and high subsonic *ed of the B-1 during low altitude penetration would further degrade interceptor kill capability. In addition, the higher penetration speed of the B-1 would reduce the time spent within the surveillance coverage of a SUAWACS by nearly 40 percent compared with the B-52.

Of course, bomber penetration capabilities could be further enhanced by employing air-to-surface missiles, such as SRAM or the air-launched cruise missile, against surfaced-based control facilities and interceptor bases. In sum, the USAF belived as of 1975 that the deployment of a SUAWACS would present a "formidable but not surmountable" problem to a bomber force. US Air Force studies acknowledged this threat and concluded that the advanced technology incorporated in the design of the B1 will ensure continued bomber penetration capability against advanced defensive systems such as a Soviet AWACS.

By 1980 the Soviets were progressing in their attempt to acquire a true AWACS capability. The USSR had now advanced from the TU-126/MOSS, which has serious shortcomings, to the Modified MOSS, which was flight-testing upgraded avionics. The CANDID AWACS, expected to reach initial operational capabi1ity (IOC} in 1983, ultimately was expected to provide the Soviets with an all-purpose. overland and overwater strategic defense and theater operations support capability. On the basis of preliminary assessments, the US believed it would be able to detect and track bomber-size targets to the radar horizon and to detect and track low-altitude, cruise-missile-size (0.l m2) targets operating over land to 130 km. The US estimated the system would be able to process up to 50 targets and conduct multiple simultaneous intercepts. Time on station will be about 6 hours unrefueled, and 15 hours with one refueling for an 800-nm-radius mission.

The Soviets were expected to increase the size of their AWACS fleet as well as to improve significantly the capabiiities of the aircraft within the fleet. Soviet perception of the future threat as characterized by large numbers of small-size cruise missiles, high-speed attack weapons, and penetrating bombers could possibly lead them to build a large AWACS fleet, perhaps 100 aircraft by the end of the 20th century. This force would complement ground-based capabilttfes and be integrated into the USSR's air defense coomand-and-control system. The AWACS-led defense against mass aerodynamic threats was expected to concentrate on overwater, and later overland, approaches to the European USSR. DIA did not believe, however, that the Soviets would attempt to provide AWACS coverage of their entire national periphery.

The Soviet Union had been involved tn Airborne Warning and Control System aircraft development since at least the mid-l960s. Moscow considers the AWACS a strategic asset and has assigned all AWACS aircraft to the National Air Defense Forces (PVO Strany). The primary AWACS mission is defense of national airspace against massed bomber and cruise missile attacks. The second most important expected mission was battlefield support of Front air operations.

As an airborne air battle command post, the AWACS would enhance overland flexibility and responsiveness in both strategic and tactical applications. As a situation and intelligence synthesizer, the AWACS would contribute to the success of a ground-based authority in planning and executing operations. The Siauliat unit, home of the MOSS AWACS, was viewed by the Soviets as an experimental squadron which had an inherent operational capability for use in time of war. Its peacetime employment has been exploratory in tactics, equipment, and operations. A full AWACS operational capability can be obtained only with mass production, deployment, and routine daily operations.

The Soviet concept of operations for their AWACS fleet would probably involve transient orbit manning. This meant all potential orbits will not be manned at all times. Approaches to European USSR through the northern, Baltic, and southern littorals, as well as the Pacific maritime approaches to the Vladivostok and Petropavlovsk areas, would be critical areas for national defense. In the secondary-mission area of theater support, central European and Chinese border regions would be paramount.

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Page last modified: 13-09-2021 17:21:55 ZULU