United Kingdom
Despite the fact that the first prototype of the radar patrol aircraft appeared in the United Kingdom earlier than in the United States, the British in the post-war period did not manage to create a truly effective AWACS machine. As mentioned in the first part of the review, the first carrier-based AWACS aircraft in Royal Navy were Skyraider AEW.1. By the mid-50s, these piston machines were certainly outdated and required replacement. As an alternative, the platform of the turboprop deck-mounted Fairey Gannet AS.1 was chosen. This anti-submarine aircraft began to enter the naval aviation in 1954. Among the advantages of the new anti-submarine were reliability and ease of control, the aircraft could patrol for 5-6 hours with 400 kg of combat load in the form of depth charges or NAR.
On August 20, 1958, the first test flight of the prototype of the carrier-based aircraft of the Gannet AEW.3 radar patrol took place, and on December 2, the first production copy was delivered. If the base for the deck air radar picket was chosen quite well, then the situation with the radar was not so good. Despite a fairly developed radio-electronic industry, the UK was unable to create a compact aircraft all-round radar. As a result, an American AN / APS-20E radar was installed on the plane, a prototype of which appeared during the Second World War. For the late 40s, it was a fairly perfect station, with a detection range of large high-altitude air targets of more than 200 km. But by 1958, it was clearly outdated and no longer met modern requirements, especially in terms of the ability to see low-altitude air targets against the background of the underlying surface.
However, the British, very much afraid of the Soviet Tu-16s armed with anti-ship missiles, hastened to launch the deck-based Gunnet into series, albeit not equipped with the most modern radar. As in the radar "Skyrader", the AN / APS-20E station was located in the ventral fairing. To provide the necessary clearance between the fairing and the deck of the aircraft carrier, it was necessary to lengthen the landing gear, and to compensate for the disturbances introduced by the fairing and maintain longitudinal stability, the vertical tail area had to be increased. To maintain the same maximum speed, due to the increased drag, the power of the power plant was increased to 3875 hp. With a maximum takeoff weight of just over 10,000 kg, the aircraft could fly 1,500 km and reach a maximum speed of 490 km / h. Patrol speed is about 300 km / h. The ceiling is 7200 meters. But the Gannets, as a rule, did not rise to an altitude of more than 4000-5000 meters.
Gannet AEW.3
In flight, the radar was served by two crew members - a radar operator and a radio engineer. The plane was controlled by one pilot - he is also the commander. There was no automated data transmission equipment on the plane, the air situation notification was issued by voice over the radio. The working conditions were very cramped, and it was a difficult test for the operator and flight engineer to spend 5-6 hours in a cramped cabin on all sides with radar and communication equipment. In addition, in the event of an emergency landing on the water, they had little chance of getting out. Instead of a transparent hinged canopy of the navigator's cockpit, two narrow doors appeared in the sides of the fuselage.
A total of 44 Gannet AEWs were built from 1958 to 1960. 3. All of them were organizationally consolidated into the 849th squadron, which was directly subordinate to the main aviation headquarters of the Navy. For lack of a better aircraft, they were actively used from the decks of British aircraft carriers and coastal airfields of naval aviation. The active operation of these machines in the British Navy continued until the end of the 70s. The last Gannet AEWs were written off shortly before the Falklands events, which the British later greatly regretted.
Until a certain point, the functions of the advanced radar patrol in the UK were assigned to the Navy ships and deck Gannet AEW. However, in the second half of the 60s, after the appearance of the supersonic long-range Tu-22 bombers and cruise missiles in the arsenal of the USSR Air Force, it became clear that the Royal Air Force needed AWACS aircraft with a long flight range and significant patrol times to move the air target detection line. The situation was aggravated by the fact that in the late 60s, in order to save money, the British leadership decided to abandon full-fledged aircraft carriers with supersonic interceptors. According to the British air defense program adopted at the end of the 60s, known as the "Mediator", the Air Force was responsible for controlling the airspace at a distance of up to 600 km and sea areas up to 1300 km from the British Isles (for more details here: Air Defense System of Great Britain. (Part 2)).
In this situation, the British Air Force needed a heavy radar patrol aircraft with a significant range and duration of flight. It is not known in whose "bright" mind the idea came to build an AWACS aircraft on the basis of the ancient patrol aircraft with piston engines Avro Shackleton, and how this idea was successfully pushed through the main headquarters of the Air Force. The lineage of this aircraft, which was put into mass production in 1951, goes back to the Avro Lancaster World War II bomber. In total, until 1958, 185 archaic-looking patrol aircraft were built.
"Shackleton", whose engines ran on high-octane gasoline, did not shine with advanced solutions and high flight performance, but it could stay in the air for more than 14 hours and cover a distance of 4300 km. The maximum speed of the aircraft reached 460 km / h, which was only 10 km / h more than the speed of the Lancaster bomber. On board there were full-fledged berths for a shift crew of 12 people and a kitchen. Taking into account the fact that on the Gannet AEW.3 aircraft the AN / APS-20E radar was serviced by 2 people, it is not clear what 8 radar operators were doing on board the Shelkton.
Shackleton AEW.2
Since 1971, 12 rare aircraft have been converted into the AWACS version. Radars were no less ancient on these machines. The British did not come up with anything better than to use the used AN / APS-20E radars removed from the Gannets. In order to somehow bring the outdated stations to the modern level, specialists from Marconi-Elliott Avionic Systems developed a digital indicator of moving targets in 1973. This somewhat reduced the effect of weather conditions on the operation of the radar and increased the detection range. At the same time, there was no automated data transmission system on the Shackleton, and the notification of detected air targets was in Morse code, or in voice mode. The only advantage of the Shackleton AEW.2 was budget savings, since it did not have to spend money on the construction of new aircraft and radars. But there was no need to talk about efficiency either, the Shackleton in the AWACS version was hopelessly losing to the American Hokai and the Soviet Tu-126. Even the Chinese KJ-1, which did not enter the series, looked much more advantageous.
Two types of AWACS aircraft, which were simultaneously in service with the British Air Force
Of course, the Shackleton could not be considered a full-fledged radar patrol aircraft. Apparently, the British themselves were aware of this, which was reflected in the circle of his tasks. All the aircraft, combined into one 8th Air Force Squadron, were more involved in the search for Soviet submarines that surfaced at night to recharge the batteries and sailing under the snorkel, or in search and rescue operations in the North Atlantic. In ideal conditions, the AN / APS-20E radar could detect a submarine at a distance of up to 200 km. One way or another, the rare "Shackleton" were exploited for a surprisingly long time and at the end of the 80s they looked pretty touching.
During the operation of aircraft with liquid-cooled Rolls-Royce Griffon 57A V-12 piston engines, the Air Force had to solve the problem of supplying them with high-octane gasoline. By that time, the turbojet engines of most British combat aircraft were running on aviation kerosene. One of the last aircraft in service crashed on April 30, 1990. The Shackleton AEW.2 was officially decommissioned in 1991.
Already in 1971, when piston "Shackleton" with outdated radars had just begun to enter the Air Force, it was absolutely clear that these hopelessly outdated machines could only nominally be considered AWACS aircraft and were a temporary option. British admirals at one time hoped to purchase the deck "Hawkeye". However, the first E-2A Hawkeyes showed poor reliability and glider problems.
By the time a fully functional version of the E-2C appeared, the British fleet had already lost full-fledged aircraft carriers, and for coastal deployment, according to the British, the E-2C Hawkeye had insufficient range. After a period of long deliberation, the British Department of Defense rejected the project proposed by Lockheed for an AWACS aircraft on the platform of the base patrol P-3 Orion. Also, the "air radar picket" based on the Buccaneer deck bomber did not advance beyond the paper design stage. On this machine, it was supposed to use two spaced apart radars in the nose and tail.
The new British AWACS aircraft could be quickly created by installing the American AN / APS-125 pulse-Doppler radar on its Nimrod MR2 anti-submarine. "Nimrod", created on the basis of the Comet 4C airliner, has proven itself well as an anti-submarine patrol aircraft and long-range reconnaissance aircraft. A total of 51 "Nimrods" of various modifications were built. But the directors of British large military-industrial corporations, not wanting to share their profits with the Americans, managed to convince the Labor government that came to power that they themselves could create a modern radio-technical complex, not inferior in its characteristics to the American AWACS system. In addition to budget savings due to unification with the Nimrod MR2 anti-submarine, the executives of Marconi-Elliott Avionic Systems and British Aerospace promised that the new British AWACS aircraft will have a high export potential, which in the future will make it possible to “recoup” the money spent on the program. This is how this adventure began, which in Great Britain they prefer not to remember once again.
The first prototype of the Nimrod Airborne flew in 1977. Outwardly, the plane turned out to be extremely ugly. British developers once again decided to be original and used a rather rare scheme with two radar antennas spaced apart.
Nimrod AEW.3
The already not the most elegant "Nimrod" received "decoration" in the form of two bulky radomes in the nose and tail. British designers believed that such an arrangement, in comparison with the rotating "disc-shaped" antenna above the fuselage, would significantly reduce the mass of the RTK as a whole and reduce aerodynamic drag. Diversity dual-frequency antennas of the AN / APY-920 radar eliminated the appearance of "dead zones" as a result of shadowing from the elements of the fuselage, wing and tail. Each antenna provided 180 degree coverage.
On paper, the radar offered by Marconi looked very promising by the standards of the mid-70s. The detection range of high-altitude air targets could reach 450 km. The radio-technical complex was supposed to automatically determine the range, altitude, speed and bearing of the target. Particular attention was paid to the possibility of detecting low-altitude air targets against the background of a stormy sea surface, in addition, according to the developers, the station could see submarine periscopes at a great distance, which should have significantly expanded the capabilities of anti-submarine defense. Thanks to the widespread use of high-performance computers, simultaneous tracking of at least 400 surface and air targets was provided, and the number of operators compared to the American AWACS and U E-3A aircraft was halved.
The first three Nimrod AEW.3s used for testing were converted from anti-submarine modifications. In 1980, serial construction began, for which the groundwork for Nimrod MR2 gliders was used. Despite numerous complaints about the operation of electronic equipment and computers Mod. 4180, the first aircraft in 1984 for crew training was transferred to the 8th AWACS combat squadron.
It is not clear what the RAF command was guided by when accepting an aircraft with an absolutely inoperative RTK. Nevertheless, the British Airspace Corporation, taking into account the first prototypes, managed to build 11 copies of the Nimrod AEW.3. At the same time, despite all efforts, the specialists of the "Marconi" company did not manage to bring the hardware part up to standard. On the new aircraft, the AWACS did not work, or showed unsatisfactory characteristics, almost all the equipment - the radar was not able to work normally for low-altitude targets, the onboard computers were constantly "hanging", the automated data transmission system often failed, and it turned out that the radio-electronic compatibility of radar and communication the hardware was initially poor. The main problem was that due to the insufficient power of the radar transmitter and the low selectivity of the receiver in terms of the signal-to-noise parameter, the signal reflected from the target almost merged with the background, and the computer, whose power was insufficient, could not stably highlight the target mark against the background of the earth.
For a long time, top managers of the Marconi Avionics company fed the government and the military with "lunches", promising that all problems would be solved soon, and that the "unparalleled" RTK of the Nimrod AEW.3 aircraft would eventually surpass all competitors. After 10 years from the beginning of the program, it became clear that it did not have any distinct prospects. Although by 1986 the radar developers managed to solve most of the problems with target detection against the background of the underlying surface, the patience of the British leadership snapped and the program was closed.
The initially dead-born Nimrod Airborne cost over $ 1 billion in early 1980s prices. At that time, it was quite possible to build a full-fledged aircraft carrier with this money. Thus, Labor's desire to save on military spending has led to many times greater spending. The fate of the "Nimrods" built in the AWACS version turned out to be unenviable. After 1986, they were mothballed at Abingdon airbase, and in the second half of the 90s they were "disposed of". To the development costs of the Nimrod Airborne, about $ 900 million had to be added, which was eventually spent on the purchase of six E-3D AWACS in the USA, which received the RAF designation Sentry AEW1. Thus, in the 70-80s, the program of creating its own British AWACS aircraft became the greatest failure of the British military-industrial complex and a real "cut" of budgetary funds. The failure to fine-tune the radio-technical complex was one of the reasons for the liquidation of Marconi Avionix. However, the company did not disappear completely, but split into several specialized firms.
In the mid-1980s, the British Army launched a program to create a radar reconnaissance aircraft capable of monitoring the battlefield in conditions of poor visual visibility or at night. A light multipurpose aircraft with two Britten-Norman BN-2T Defender turboprop engines was chosen as the aviation platform. This machine is still popular due to its relatively low cost and ability to operate from poorly equipped unpaved airfields. In the transport or patrol version, "Defender" was used or is used in about 40 countries around the world. In 1984, the first aircraft equipped with a radar with a disc-shaped radome in the nose took off. In addition to the radar, under each wing there were 2 hardpoints for bombs and NAR blocks, which made it possible not only to observe the detected ground targets, but also to strike at them. Apparently, the capabilities of this machine did not satisfy the British military and orders for a radar reconnaissance aircraft did not follow.
In 1988, an AWACS aircraft with a massive spherical fairing in front of the aircraft flew for the first time. On this machine, created within the framework of the ASTOR program (English Airborne Stand-Off Radar), the pulse-Doppler radar Skymaster of the British company Thorn-EMI was used. Radars of the same type were supplied to the PRC and were used on Chinese Y-8J aircraft.
The Skymaster radar provided an overview in the 280-degree sector and could simultaneously observe 50 air and 32 surface targets at a distance of up to 200 km. The avionics included two consoles: one for detecting targets, the other for aiming combat aircraft at them. In the future, it was planned to install data transmission equipment, state identification and radio intelligence systems. To prevent the massive round nose with the radar antenna from touching the ground, the front landing gear was lengthened by 30 cm. Despite the relatively small maximum take-off weight of 3900 kg, the aircraft could patrol for 6 hours at a distance of 100 km from its airfield. Patrol altitude up to 6000 meters, at a speed of 315 km / h. The crew included two pilots and two RTK operators.
In general, given the low cost and low operating costs, the aircraft was not bad as an auxiliary air "radar picket". He participated in a number of aviation exhibitions and was actively offered for export. There is evidence that the BN-2T AEW Defender participated in the 1991 campaign against Iraq. However, foreign customers showed no interest, and the British Air Force preferred more advanced radar patrol aircraft.
Based on the experience of the "Gulf War", a special expert group of the British Air Force formed the requirements for the aircraft for radar and radio-technical reconnaissance of ground targets. However, due to the end of the Cold War and cuts in defense spending, it was only in 1999 that a competition was announced to select an aviation platform for placing a radio-technical complex. The main contenders were Global Express from Bombardier and Raytheon and Golfstream V from Lockheed Martin and Northrop Grumman. The winner was the Global Express businessjet, mainly due to its larger internal volumes and more powerful generators.
In the same year, the Raytheon Corporation began the creation of electronic stuffing under the ASTOR program. The onboard equipment of the aircraft being created was supposed to provide remote radar and radio-technical reconnaissance and control of the delivery of air and artillery strikes in real time. The prototype of the ground target reconnaissance radar was the ASARS-2 station, which was originally developed for the U-2 high-altitude reconnaissance aircraft. This radar with an antenna length of 4.8 meters is capable of providing selection of moving targets, high-resolution terrain mapping and frame-by-frame shooting of stationary objects. The creation of the Sentinel R1 radio-technical complex was carried out with the involvement of broad international cooperation. In addition to Raytheon, the British GEC-Marconi and the French Thomson-CSF took part in the work on equipping the aircraft with equipment.
ASTOR system functioning diagram
In addition to a radar, an electronic reconnaissance station, electronic warfare equipment and a self-defense complex in the form of towed jammers, automatic fire traps and equipment for detecting the launch of missiles and aviation missile launchers, there is a state-of-the-art system for displaying data and detailing the information received in the form of large-format maps moving on the screen. displays. At the same time, the analysts and control officers on board the aircraft are able to simultaneously coordinate the actions of dozens of drones and combat aircraft.
Mobile ground control stations can operate in conjunction with the ASTOR system aircraft. The collection and transmission of data is fully automated. After the tests revealed the ability of the equipment to detect submarine periscopes and small inflatable boats at a great distance, the British Navy showed interest in the Sentinel R1 aircraft. After the decommissioning of the Nimrod MR2 patrols, the British fleet was left without its own long-range scouts and was forced to rent American RC-135s. According to the admirals of the Royal Navy, the modified Guardians are quite suitable for the role of naval patrol and reconnaissance aircraft, but their purchase in the near future due to financial constraints is extremely unlikely.
Sentinel R1
The flight of the first prototype took place in August 2001. The first serial "Guard" with a full complex of avionics began testing on May 26, 2004. The British Department of Defense ordered 5 aircraft and eight mobile ground stations (six on wheeled off-road cross-country vehicles and two in containers transported by air). The cost of the program, taking into account R&D, was £ 850 million. The cost of maintaining aircraft and ground infrastructure for the period up to 2018 should not exceed £ 54.4 million per year.
The aircraft with a maximum takeoff weight of 42,400 kg is capable of patrolling for 9 hours. During this time, he can fly 9250 km. To increase the secrecy and range of the reconnaissance complex, patrols are usually conducted at an altitude of 12,000 meters. The crew consists of two pilots, two RTK operators and one control officer. The aircraft also provides space for additional personnel and replacement crew.
Operators of RTK Sentinel R1
According to the British media, the Sentinel R1's capabilities are comparable to the much more expensive and sophisticated American E-8C JSTARS. It is reported that in addition to monitoring ground targets, the British reconnaissance aircraft's dual-mode radar is capable of detecting "complex" low-altitude aerial targets such as cruise missiles, helicopters and drones. Thanks to the high degree of automation and the more advanced composition of the RTK, the number of the Sentinel crew was reduced to a minimum. At the moment, the "home" of British radar reconnaissance aircraft is Waddington Air Force Base in Lincolnshire. All capable British Sentry AEW1s are also based there.
The baptism of fire of the Sentinel R1 took place in 2009 in Afghanistan. There, radar reconnaissance aircraft monitored Taliban vehicles, identified the places where improvised explosive devices were planted on the roads, coordinated air and artillery strikes, and also intercepted radio. It is noted that in a number of cases it was possible to detect the movement of rebel groups on foot. Due to the high sensitivity of the RTK, it is possible to track people armed with small arms. In 2011, the Guardians made a significant contribution to the coordination of the actions of the British and French military aircraft, which bombed government forces in Libya. In 2013, one aircraft was involved in supporting the operations of the French contingent in Mali. In May 2014, Sentinel R1 was sent to Ghana to assist in the search for schoolgirls abducted in Nigeria by the Islamist group Boko Haaram. In March 2015, the British Ministry of Defense announced the deployment of two reconnaissance aircraft to the Middle East to help Iraqi government forces in the fight against Islamists.
During the armed confrontation with Argentina in 1982, the British fleet was in dire need of AWACS aircraft. In a number of cases, Argentine aircraft and Exocet anti-ship missiles managed to break through to the ships of the British squadron and were visually detected at the last moment. The enlightened British navigators were very lucky that more than half of the free-falling American-made bombs that hit the ships did not explode, and Argentina had very little anti-ship missiles, otherwise the outcome of the war could have been completely different. Since full-fledged aircraft carriers in Great Britain were decommissioned in the early 70s, and only short or vertical takeoff and landing aircraft and helicopters could be based on the remaining Invincible-class ships, there was no question of adopting AWACS deck aircraft, and all attention was concentrated on helicopters …
Soon after the end of the Falklands epic, in the second half of 1982, the re-equipment of the Sea King HAS. Mk.1 heavy anti-submarine helicopter into a version of the radar patrol began. These Sikorsky rotorcraft were built in the UK under license. For the sake of fairness, it should be said that the constrictors of the British firm Westland have seriously reworked and improved the original version.
On the former PLO helicopter, instead of the dismantled sonar equipment, a radio engineering complex was installed, which included a surveillance radar, a state identification system, an electronic intelligence station, data processing and display equipment and communication facilities. The converted helicopter was designated Sea King AEW. Mk2. Its most notable external feature was the large, hemispherical radome on the starboard side of the helicopter.
Sea King AEW. Mk2
The radio-transparent plastic fairing of the Searchwater radar in the working position was lowered down, and when landing on the ship it folded along the side. This radar, created by Thorn-EMI, was proposed for installation on Nimrod MR2 anti-submarine aircraft, but was eventually used on the Sea King's radar modification. In the first version, the mass of the radar equipment reached 550 kg. The helicopter, equipped with Searchwater radar, performed well. A helicopter with a maximum takeoff weight of 9760 kg could patrol for 2 hours at a distance of 100 km from the ship. With a flight altitude of 3000 meters, it was possible to detect large air targets at a distance of up to 230 km and simultaneously track 40 air and surface targets. The helicopter was controlled by 2 pilots, 2 operators were engaged in the maintenance of the radio technical complex. Operators had 3 all-round visibility indicators at their disposal. Initially, the issuance of a notification about detected targets was carried out by voice over the radio, but later, equipment for automated data transmission was created and implemented.
After successful tests of the AWACS helicopter and eliminating the identified shortcomings, the British fleet, in addition to the first two prototypes converted from anti-submarine modification, ordered a batch of eight new machines. In 1985, they entered the 849th Naval Aviation Squadron. Serial Sea King AEW.5 helicopters outwardly differed from the first prototypes with antennas of an automated radar information transmission system. Also, thanks to the introduction of compact high-performance computers, the number of tracked targets increased to 200. On this modification, in order to reduce the weight of the radar radome, it was made soft. Before the start of the radar operation, compressed air was supplied inside the fairing, and it was straightened.
The first aircraft-carrying ship of the British Navy, from the deck of which AWACS helicopters carried out regular patrol flights, was Illustrious. Following him in 1986, the Sea Kings radar became part of the carrier-based air wing of the aircraft carrier Invincible. By the end of the 80s, 3 more Sea King HAS 5 anti-submarine missiles were converted into the radar version, after which the number of air radar pickets in the British fleet reached 13 units.
In the second half of the 90s, the characteristics of the radio technical complex ceased to meet modern requirements, in particular, the British admirals were not satisfied with the limited possibilities for detecting high-altitude high-speed targets flying above the horizon and the station's low productivity. In 1997, Thales won the competition to modernize the Sea King AEW. Initially, it was planned to modernize all 13 helicopters, but later their number was reduced to 9.
The basis of the RTK of the modernized Sea King AEW.7 was the Searchwater 2000 radar. In comparison with the previous radar, its power increased 3 times. Thanks to this, the detection range and noise immunity have increased. The introduction of modern information processors made it possible not only to stably detect and track targets against the background of the earth's surface, but also to detect moving ground vehicles. At the same time, the number of monitored objects can reach 250. The bot complex also includes modern secure communication equipment and a high-speed digital data transmission channel operating in the frequency range of 960-1, 215 MHz.
To replace the Sea King AEW.7 AWACS helicopters, whose operation is due to end in 2018, Thales has developed the Crowsnest helicopter early warning radar system, based on the upgraded Searchwater 2000 radar.
The $ 806 million tender provides for the supply of 8 AgustaWestland AW101 Merlin Hm2 helicopters equipped with special equipment. In it, the American corporation Lockheed Martin competed with Thales for the right to supply the radar part and equipment for information display posts. However, Royal Navy experts preferred the British radar system, whose prototype appeared in the late 70s. Most likely this is not due to the superiority of the radar of its own production, but to the unwillingness to share the already meager defense orders with "American partners."
