The Pratt & Whitney JT3D is an early turbofan aircraft engine derived from the Pratt & Whitney JT3C . It was first run in 1958 and was first flown in 1959 under a B-45 Tornado test aircraft. Over 8,000 JT3Ds were produced between 1959 and 1985. Most JT3D engines still in service today are used on military aircraft, where the engine is referred to by its US military designation of TF33 .
91-581: The Boeing E-3 Sentry is an American airborne early warning and control (AEW&C) aircraft developed by Boeing . E-3s are commonly known as AWACS (Airborne Warning and Control System). Derived from the Boeing 707 airliner, it provides all-weather surveillance, command, control, and communications, and is used by the United States Air Force , NATO , French Air and Space Force , Royal Saudi Air Force and Chilean Air Force . The E-3 has
182-528: A High-level programming language instead of assembly language . Significant improvement came from adding pulse compression to the pulse-Doppler mode. These hardware and software modifications improve the E-3 radars' performance, providing enhanced detection with an emphasis towards low radar cross-section (RCS) targets. The RAF had also joined the USAF in adding RSIP to upgrade the E-3's radars. The retrofitting of
273-667: A 360 degree coverage, the radar antenna of the Chinese AWACS does not rotate. Instead, three PAR antenna modules are placed in a triangular configuration inside the round radome to provide a 360 degree coverage. The installation of equipment at the Il-76 began in late 2002 aircraft by Xian aircraft industries (Xian Aircraft Industry Co.). The first flight of an airplane KJ-2000 made in November 2003. All four machines will be equipped with this type. The last to be introduced into service
364-485: A Russian-made Ilyushin-76 cargo plane [also incorrectly reported as a Beriev A-50 Mainstay] with advanced Elta electronic, computer, radar and communications systems. Beijing was expected to acquire several Phalcon AEW systems, and reportedly could buy at least three more [and possibly up to eight] of these systems, the prototype of which was planned for testing beginning in 2000. In July 2000, the US pressured Israel to back out of
455-509: A crucial role of directing coalition aircraft against Iraqi forces. The aircraft was also the last of the Boeing 707 derivatives after 34 years of continuous production. The aircraft's capabilities have been maintained and enhanced through numerous upgrades. In 1996, Westinghouse Electric's Defense & Electronic Systems division was acquired by Northrop Corporation, before being renamed Northrop Grumman Mission Systems, which currently supports
546-512: A different installation was used to direct Bristol Beaufighters toward Heinkel He 111s , which were air-launching V-1 flying bombs . In February 1944, the US Navy ordered the development of a radar system that could be carried aloft in an aircraft under Project Cadillac. A prototype system was built and flown in August on a modified TBM Avenger torpedo bomber . Tests were successful, with
637-571: A distinctive rotating radar dome (rotodome) above the fuselage. Production ended in 1992 after 68 aircraft had been built. In the mid-1960s, the U.S. Air Force (USAF) was seeking an aircraft to replace its piston-engined Lockheed EC-121 Warning Star , which had been in service for over a decade. After issuing preliminary development contracts to three companies, the USAF picked Boeing to construct two airframes to test Westinghouse Electric 's and Hughes 's competing radars. Both radars used pulse-Doppler technology , with Westinghouse's design emerging as
728-454: A full-length fan cowl. Pratt & Whitney provided a kit whereby JT3Cs could be converted to the JT3D specification, and performance, during an overhaul. In 1959, important orders for the engine were the Boeing 707-120B and Boeing 720B when American Airlines ordered one 707 powered by JT3D turbofans and KLM ordered a JT3D-powered Douglas DC-8 . Earlier 707s and DC-8s had been powered by
819-478: A major advance in capability, being the first AEW to use a pulse-Doppler radar , which allowed it to track targets normally lost in ground clutter. Previously, low-flying aircraft could only be readily tracked over water. The AWACS features a three-dimensional radar that measures azimuth, range, and elevation simultaneously; the unit installed upon the E-767 has superior surveillance capability over water compared to
910-499: A major asset in an AEW aircraft. Following a crash, the US Navy opted to discontinue lighter than air operations in 1962. In 1958, the Soviet Tupolev Design Bureau was ordered to design an AEW aircraft. After determining that the projected radar instrumentation would not fit in a Tupolev Tu-95 or a Tupolev Tu-116 , the decision was made to use the more capacious Tupolev Tu-114 instead. This solved
1001-612: A maximum range of over 850 km at 9,000 metres (30,000 ft) altitude. The Swedish Air Force uses the S 100D Argus ASC890 as its AEW platform. The S 100D Argus is based on the Saab 340 with an Ericsson Erieye PS-890 radar. Saab also offers the Bombardier Global 6000 -based GlobalEye . In early 2006, the Pakistan Air Force ordered six Erieye AEW equipped Saab 2000s from Sweden. In December 2006,
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#17327802774391092-574: A programmable 18- bit computer whose software could be modified before each mission. This computer was the AN/AYK-8 design from the B-57G program, and designated AYK-8-EP1 for its much expanded memory. This radar also multiplexed a beyond-the-horizon (BTH) pulse mode that could complement the pulse- Doppler radar mode. This proved to be beneficial especially when the BTH mode is used to detect ships at sea when
1183-483: A pseudorandom set of frequencies and also have very short scanning rates, which makes them difficult to detect and jam. Up to 1000 targets can be tracked simultaneously to a range of 243 mi (450 km), while at the same time, multitudes of air-to-air interceptions or air-to-surface (including maritime) attacks can be guided simultaneously. The radar equipment of the Israeli AEW&;C consists of each L-band radar on
1274-556: A purpose-built aircraft, but tests indicated it would not outperform the already-operational 707, so the latter was chosen instead. To increase endurance, this design was to be powered by eight General Electric TF34s . It would carry its radar in a rotating dome mounted at the top of a forward-swept tail, above the fuselage. Boeing was selected ahead of McDonnell Douglas 's DC-8 -based proposal in July 1970. Initial orders were placed for two aircraft, designated EC-137D, as test beds to evaluate
1365-409: A radar screen to monitor Iraqi forces. During Operation Desert Storm, E-3s flew 379 missions and logged 5,052 hours of on-station time. The data collection capability of the E-3 radar and computer subsystems allowed an entire air war to be recorded for the first time. In addition to providing senior leadership with time-critical information on the actions of enemy forces, E-3 controllers assisted in 38 of
1456-497: A range of approximately 400 mi (650 km) for aircraft flying at medium to high altitudes. The radar, combined with a secondary surveillance radar (SSR) and electronic support measures (ESM), provides a look down capability, to detect, identify, and track low-flying aircraft, while eliminating ground clutter returns. Between 1987 and 2001, USAF E-3s were upgraded under the "Block 30/35 Modification Program". Enhancements included: The Radar System Improvement Program (RSIP)
1547-669: A substantial AEW capability, initially with American Douglas AD-4W Skyraiders , designated Skyraider AEW.1, which in turn were replaced by the Fairey Gannet AEW.3 , using the same AN/APS-20 radar. With the retirement of conventional aircraft carriers, the Gannet was withdrawn and the Royal Air Force (RAF) installed the radars from the Gannets on Avro Shackleton MR.2 airframes, redesignated Shackleton AEW.2. To replace
1638-462: A three-week long cybersecurity vulnerability test revealed that the 40/45 block and its supporting ground equipment were vulnerable to cyber threats, and were thus deemed "not survivable." This caused a delay of approximately two years. Twenty-four E-3s are projected to complete this upgrade to 40/45 by the end of fiscal year 2020, while seven aircraft will be retired to save upgrade costs and harvest out-of-production components. NATO intends to extend
1729-594: A total of thirty E-3s in active service. Twenty-six are stationed at Tinker AFB and belong to the Air Combat Command (ACC). Four are assigned to the Pacific Air Forces (PACAF) and stationed at Kadena AB , Okinawa and Elmendorf AFB , Alaska. One aircraft (TS-3) was assigned to Boeing for testing and development (retired/scrapped June 2012). E-3 Sentry aircraft were among the first to deploy during Operation Desert Shield , where they established
1820-684: A value of upwards of $ 40 million which will be used to support the remaining active aircraft. Some of the parts to be removed are no longer on the market or have become very expensive. E-3s have been involved in three hull-loss accidents, and one radar antenna was destroyed during RSIP development (see photo under Avionics). Data from : E-3 Sentry (AWACS) General characteristics Performance Avionics Related development Aircraft of comparable role, configuration, and era Related lists Notes Citations Bibliography Airborne early warning and control An airborne early warning and control ( AEW&C ) system
1911-512: Is an airborne radar early warning system designed to detect aircraft , ships , vehicles , missiles and other incoming projectiles at long ranges, as well as performing command and control of the battlespace in aerial engagements by informing and directing friendly fighter and attack aircraft . AEW&C units are also used to carry out aerial surveillance over ground and maritime targets , and frequently perform battle management command and control (BMC2). When used at altitude,
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#17327802774392002-530: Is considered to be both more capable and less expensive to operate than the older Boeing 707-based Phalcon fleet. In 2017, India announced plans to purchase six airborne early warning and control (AEW&C) ("AWACS") aircraft that can also perform aerial refuelling, with the first two AEW&C aircraft awaiting approval by Cabinet in 2020. However, in September 2021, it was decided to use six Airbus A321s acquired from Air India instead. On 3 June 1957,
2093-488: Is currently in service with Israel, Italy, and Singapore. Instead of using a rotodome, a moving radar was found on some AEW&C aircraft, and the EL/W-2085 used an active electronically scanned array (AESA) – an active phased array radar. This radar consists of an array of transmit/receive (T/R) modules that allow a beam to be electronically steered, making a physically rotating rotodome unnecessary. AESA radars operate on
2184-602: Is the only model remaining in United States Air Force service. It is expected to remain as a mainstay of the Air Force heavy bomber fleet until at least 2040, with options for replacing the 8 TF33 engines with more modern equivalents being considered. In April 2020, the USAF released a request for proposals for 608 commercial replacement engines, with the plan to award the contract in May 2021. In September 2021,
2275-817: The AN/APY-1 [ uk ] and AN/APY-2 passive electronically scanned array radar system to provide surveillance from the Earth's surface up into the stratosphere , over land or water. Other major subsystems in the E-3 Sentry are navigation, communications, and computers. 14 consoles display computer-processed data in graphic and tabular format on screens. Its operators perform surveillance, identification, weapons control, battle management and communications functions. Data may be forwarded in real-time to any major command and control center in rear areas or aboard ships. In times of crisis, data may also be forwarded to
2366-763: The Indian Air Force (IAF) and Defence Research and Development Organisation (DRDO) began a study of requirements for developing an Airborne Early Warning and Control (AWAC) system. In 2015, DRDO delivered 3 AWACs, called Netra , to the IAF with an advanced Indian AESA radar system fitted on the Brazilian Embraer EMB-145 air frame. Netra gives a 240-degree coverage of airspace. The Emb-145 also has air-to-air refuelling capability for longer surveillance time. The IAF also operates three Israeli EL/W-2090 systems, mounted on Ilyushin Il-76 airframes,
2457-659: The Italian Navy is operated from the aircraft carriers Cavour and Giuseppe Garibaldi . During the 2010s, the Royal Navy opted to replace its Sea Kings with a modular "Crowsnest" system that can be fitted to any of their Merlin HM2 fleet. The Crowsnest system was partially based upon the Sea King ASaC7's equipment; an unsuccessful bid by Lockheed Martin had proposed using a new multi-functional sensor for either
2548-484: The National Command Authority in the U.S. via RC-135 or aircraft carrier task forces. Electrical generators mounted in each of the E-3's four engines provide 1 megawatt of electrical power required by the aircraft's radars and electronics. Its pulse-Doppler radar has a range of more than 250 mi (400 km) for low-flying targets at its operating altitude, and the pulse (BTH) radar has
2639-531: The Pakistan Navy requested three excess P-3 Orion aircraft to be equipped with Hawkeye 2000 AEW systems. China and Pakistan also signed a memorandum of understanding (MoU) for the joint development of AEW&C systems. The Hellenic Air Force , Brazilian Air Force and Mexican Air Force use the Embraer R-99 with an Ericsson Erieye PS-890 radar, as on the S 100D. Israel has developed
2730-692: The RC-135 and the E-8 Joint STARS , but the program was canceled by the Department of Defense . NATO intends to extend the operational status of its AWACS until 2035 when it is due to be replaced by the Alliance Future Surveillance and Control (AFSC) program. The Royal Air Force (RAF) chose to limit investment in its E-3D fleet in the early 2000s, diverting Sentry upgrade funds to a replacement program. On 22 March 2019,
2821-652: The September 11 attacks on the World Trade Center towers and the Pentagon. NATO and RAF E-3s participated in the military intervention in Libya . From January 2011 to September 2014, NATO E-3s were deployed to Mazar-i-Sharif International Airport , Afghanistan, as part of NATO's International Security Assistance Force (ISAF) mission. The aircraft were used for air traffic control of military aircraft over
Boeing E-3 Sentry - Misplaced Pages Continue
2912-702: The Thorn-EMI ARI 5980/3 Searchwater LAST radar attached to the fuselage on a swivel arm and protected by an inflatable dome. The improved Sea King ASaC7 featured the Searchwater 2000AEW radar, which was capable of simultaneously tracking up to 400 targets, instead of an earlier limit of 250 targets. The Spanish Navy fields the SH-3 Sea King in the same role, operated from the LPH Juan Carlos I . The AgustaWestland EH-101A AEW of
3003-487: The Turkish Air Force are deploying Boeing 737 AEW&C aircraft. The Boeing 737 AEW&C has a fixed, active electronically scanned array radar antenna instead of a mechanically-rotating one, and is capable of simultaneous air and sea search, fighter control and area search, with a maximum range of over 600 km (look-up mode). In addition, the radar antenna array is also doubled as an ELINT array, with
3094-584: The United States Navy , the Northrop Grumman E-2 Hawkeye AEW&;C aircraft is assigned to its supercarriers to protect them and augment their onboard command information centers (CICs). The designation "airborne early warning" (AEW) was used for earlier similar aircraft used in the less-demanding radar picket role, such as the Fairey Gannet AEW.3 and Lockheed EC-121 Warning Star , and continues to be used by
3185-513: The $ 1 billion agreement to sell China four Phalcon phased-array radar systems. Following the cancelled A-50I/Phalcon deal, China turned to indigenous solutions. The Phalcon radar and other electronic systems were taken off from the unfinished Il-76, and the airframe was handed to China via Russia in 2002. The Chinese AWACS has a unique phased array radar (PAR) carried in a round radome. Unlike the US AWACS aircraft, which rotate their rotodomes to give
3276-613: The 1930s, the British developed a radar set that could be carried on an aircraft for what they termed "Air Controlled Interception". The intention was to cover the North West approaches where German long range Focke-Wulf Fw 200 Condor aircraft were threatening shipping. A Vickers Wellington bomber (serial R1629) was fitted with a rotating antenna array. It was tested for use against aerial targets and then for possible use against German E boats . Another radar equipped Wellington with
3367-580: The 41 air-to-air kills recorded during the conflict. NATO, UK, French and USAF AWACS played an important role in the air campaign against Serbia and Montenegro in the former republic of FR Yugoslavia . From March to June 1999 the aircraft were deployed in the NATO bombing of Yugoslavia (operation Allied Force) directing allied strike and air defence aircraft to and from their targets. Over 1,000 aircraft operating from bases in Germany and Italy took part in
3458-737: The AEW role. The "Mainstay" is based on the Ilyushin Il-76 airframe, with a large non-rotating disk radome on the rear fuselage. These replaced the 12 Tupolev Tu-126 that filled the role previously. The A-50 and A-50U will eventually be replaced by the Beriev A-100 , which features an AESA array in the radome and is based on the updated Il-476. In May 1997, Russia and Israel agreed to jointly fulfill an order from China to develop and deliver an early warning system. China reportedly ordered one Phalcon for $ 250 million, which entailed retrofitting
3549-503: The AN/APY-1 system on the earlier E-3 models. The E-2 Hawkeye was a specially designed AEW aircraft. Upon its entry to service in 1965, it was initially plagued by technical issues, causing a (later reversed) cancellation. Procurement resumed after efforts to improve reliability, such as replacement of the original rotary drum computer used for processing radar information by a Litton L-304 digital computer. In addition to purchases by
3640-733: The AW101 or another aircraft. The Russian-built Kamov Ka-31 is deployed by the Indian Navy on the aircraft carriers INS Vikramaditya and INS Vikrant and also on Talwar -class frigates . The Russian Navy has two Ka-31R variants, at least one of which was deployed on their aircraft carrier Admiral Kuznetsov in 2016. It is fitted with E-801M Oko (Eye) airborne electronic warfare radar that can track 20 targets simultaneously, detecting aircraft up to 150 km (90 mi) away, and surface warships up to 200 km (120 mi) distant. Pratt %26 Whitney JT3D Aware of
3731-573: The CJ805-23, Pratt & Whitney had not undertaken any transonic fan research prior to designing the JT3D, so they were unable to incorporate a single stage unit into the specification. Instead P&W designed a 2-stage unit based on some research they had done to support the J91 nuclear turbojet. On the Boeing 707 the JT3D fan nacelle was relatively short, whereas the Douglas DC-8 installation had
Boeing E-3 Sentry - Misplaced Pages Continue
3822-513: The Chinese Air Force until the end of 2007. China is also developing a carrier-based AEW&C, Xian KJ-600 via Y-7 derived Xian JZY-01 testbed. The EL/W-2085 is an airborne early warning and control (AEW&C) multi-band radar system developed by Israel Aerospace Industries (IAI) and its subsidiary Elta Systems of Israel. Its primary objective is to provide intelligence to maintain air superiority and conduct surveillance. The system
3913-695: The E-3 squadrons was completed in December 2000. Along with the RSIP upgrade was installation of the Global Positioning System/Inertial Navigation Systems which improved positioning accuracy. In 2002, Boeing was awarded a contract to add RSIP to the small French AWACS squadron. Installation was completed in 2006. Saudi Arabia began RSIP upgrades in 2013; the first aircraft being upgraded by Boeing in Seattle with
4004-593: The E-3's radar. In April 2022, the U.S. Air Force announced that the Boeing E-7 is to replace the E-3 beginning in 2027. In 1963, the USAF asked for proposals for an Airborne Warning and Control System (AWACS) to replace its EC-121 Warning Stars , which had served in the airborne early warning role for over a decade. The new aircraft would take advantage of improvements in radar technology and computer-aided radar data analysis and data reduction. These developments allowed airborne radars to " look down ", i.e. to detect
4095-575: The IAI/Elta EL/M-2075 Phalcon system, which uses an AESA ( active electronically scanned array ) in lieu of a rotodome antenna. The system was the first such system to enter service. The original Phalcon was mounted on a Boeing 707 and developed for the Israeli Defense Force and for export. Israel uses IAI EL/W-2085 airborne early warning and control multi-band radar system on Gulfstream G550 ; this platform
4186-480: The JT3C and JT4A turbojets, and the improved efficiency of the turbofan soon attracted the airlines. A JT3D-powered 707-123B and 720-023B (the suffix B was to indicate a turbofan-powered aircraft) entered service with American Airlines on the same day, March 12, 1961. The Boeing KC-135 Stratotankers were all originally powered by turbojet engines. With the demise of many airline 707s, the United States Air Force took
4277-453: The JT3D, while 354 were fitted with CFM International CFM56 engines, which provide greater thrust, lower fuel consumption, and increased operational flexibility due to their lower noise footprint. The noise of the JT3D is one of the reasons NATO has debated re-fitting their E-3 Sentry AWACS fleet, since the aircraft are subject to restrictions that aircraft with modern engines are not. Operational flexibility would be further increased due to
4368-834: The Ministry of Defence announced that the E-3Ds would be replaced by five E-7 Wedgetails from 2023. The £1.51 billion contract was awarded to Boeing without a competitive procurement process, a decision criticised by both competitors of Boeing and the UK's Defence Select Committee . The 2021 Integrated Defence Review confirmed a reduced order of three aircraft. On 27 January 2015, the RAF deployed an E-3D Sentry to Cyprus in support of U.S.-led coalition airstrikes against Islamic State militants in Iraq and Syria. The last operational flight by an RAF E3 Sentry
4459-731: The RAF for its Sentry AEW1 , while AEW&C (airborne early warning and control) emphasizes the command and control capabilities that may not be present on smaller or simpler radar picket aircraft. AWACS (Airborne Warning and Control System) is the name of the specific system installed in the E-3 and Japanese Boeing E-767 AEW&C airframes, but is often used as a general synonym for AEW&C. Modern AEW&C systems can detect aircraft from up to 400 km (220 nmi) away, well out of range of most surface-to-air missiles. One AEW&C aircraft flying at 9,000 m (30,000 ft) can cover an area of 312,000 km (120,000 sq mi). Three such aircraft in overlapping orbits can cover
4550-551: The S-bands. Historically, UHF radars had resolution and detection issues that made them ineffective for accurate targeting and fire control; Northrop Grumman and Lockheed claim that the APY-9 has solved these shortcomings in the APY-9 using advanced electronic scanning and high digital computing power via space/time adaptive processing. The Russian Aerospace Forces are currently using approximately 3-5 Beriev A-50 and A-50U "Shmel" in
4641-716: The Shackleton AEW.2, an AEW variant of the Hawker Siddeley Nimrod , known as the Nimrod AEW3 , was ordered in 1974. After a protracted and problematic development, this was cancelled in 1986, and seven E-3Ds, designated Sentry AEW.1 in RAF service, were purchased instead. Many countries have developed their own AEW&C systems, although the Boeing E-3 Sentry , E-7A and Northrop Grumman E-2 Hawkeye and Gulfstream/IAI EL/W-2085 are
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#17327802774394732-603: The UK Defence Secretary announced a $ 1.98 billion (~$ 2.33 billion in 2023) contract to purchase five Boeing E-7 Wedgetails . The U.S. Air Force intends to retire 15 of its 31 E-3s and acquire the E-7. On 31 March 2023, the USAF retired an E-3 from service for the first time. The E-3 Sentry's airframe is a modified Boeing 707-320B Advanced model. Modifications include a rotating radar dome ( rotodome ), uprated hydraulics from 241 to 345 bar (3500–5000 psi) to drive
4823-656: The UK effectively limited the service life of the E-3D fleet by de-funding the Project Eagle upgrade which would have seen it upgraded in line with the USAF Block 40/45 standard. AirForces Monthly reported that by December 2020, just 2 aircraft were available for operations at any one time. The Strategic Defence and Security Review 2015 had announced the intention to retain the E-3D fleet until 2035, however in March 2019,
4914-409: The US Navy, the E-2 Hawkeye has been sold to the armed forces of Egypt , France , Israel , Japan , Singapore and Taiwan . The latest E-2 version is the E-2D Advanced Hawkeye , which features the new AN/APY-9 radar. The APY-9 radar has been speculated to be capable of detecting fighter-sized stealth aircraft, which are typically optimized against high frequencies like Ka, Ku, X, C and parts of
5005-552: The United Kingdom in September 2021, arrived in Chile in July 2022; units ZH103 and ZH106 will join the "Grupo de Aviación N.º 10" of the II Air Brigade. The other E-3D will reportedly be used as a source of spare parts. NATO acquired 18 E-3As and support equipment, with the first aircraft delivered in January 1982. The aircraft are registered in Luxembourg . The eighteen E-3s were operated by Number 1, 2 and 3 Squadrons of NATO's E-3 Component, based at NATO Air Base Geilenkirchen . NATO E-3s participated in Operation Eagle Assist after
5096-412: The ability of higher power engines to increase the ceiling of the aircraft, extending the horizon for radar surveillance; for instance, RAF , French and Saudi E-3s routinely fly higher than NATO/USAF counterparts. In 1961, the TF33-powered Boeing B-52H Stratofortress entered service. The "H" model of the B-52 was the only production variant of the heavy bomber to be fitted with turbofan engines, and
5187-415: The air campaign which was intended to destroy Yugoslav air defenses and high-value targets such as the bridges across the Danube river, factories, power stations, telecommunications facilities, and military installations. On 18 November 2015, an E-3G was deployed to the Middle East to begin flying combat missions in support of Operation Inherent Resolve against ISIL, marking the first combat deployment of
5278-432: The boundaries of the U.S. or NATO countries and can direct interceptor aircraft to these targets. In support of air-to-ground operations, the E-3 can provide direct information needed for interdiction, reconnaissance, airlift, and close-air support for friendly ground forces. The unpressurized rotodome is 30 ft (9.1 m) in diameter, 6 ft (1.8 m) thick at the center, and is held 11 ft (3.4 m) above
5369-399: The competition from the Rolls-Royce Conway turbofan, Pratt & Whitney decided to develop the JT3D turbofan from the JT3C turbojet for later deliveries of the Boeing 707 and the Douglas DC-8, then nearing entry into service. A 2-stage fan replaced the first 3 stages of the 9-stage JT3C LP compressor. On the LP turbine, the second stage was enlarged and a third stage added. Unlike GE with
5460-432: The consequence of lessons learnt by the Royal Navy during the 1982 Falklands War when the lack of AEW coverage for the task force was a major tactical handicap, and rendered them vulnerable to low-level attack. The Sea King was determined to be both more practical and responsive than the proposed alternative of relying on the RAF's land-based Shackleton AEW.2 fleet. The first examples were a pair of Sea King HAS2s that had
5551-407: The contract winner. Testing on the first production E-3 began in October 1975. The first USAF E-3 was delivered in March 1977, and during the next seven years, a total of 34 aircraft were manufactured. E-3s were also purchased by NATO (18), the United Kingdom (7), France (4) and Saudi Arabia (5). In 1991, when the last aircraft had been delivered, E-3s participated in the Persian Gulf War , playing
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#17327802774395642-522: The country, as well as surveillance, and tactical management of friendly aircraft. During the mission to Afghanistan, NATO E-3s flew 1,240 missions and accumulated 12,240 flying hours. Presently, 14 NATO E-3As are in the inventory, since one E-3 was lost in a crash and three were retired from service in 2015, 2017, and 2018. The first was due for its six-year cycle Depot Level Maintenance (DLM) inspection which would have been very costly. The "449 Retirement Project" resulted in reclamation of critical parts with
5733-504: The crews can work in shifts by the use of an on-board crew rest and meals area. The aircraft are equipped with one toilet in the rear, and a urinal behind the cockpit. Saudi E-3s were delivered with an additional toilet in the rear. When deployed, the E-3 monitors an assigned area of the battlefield and provides information for commanders of air operations to gain and maintain control of the battle; while as an air defense asset, E-3s can detect, identify, and track airborne enemy forces far from
5824-408: The first of 2 HR2S-1W, a derivative of the Sikorsky CH-37 Mojave , was delivered to the US Navy, it used the AN/APS-32 but proved unreliable due to vibration. The British Sea King ASaC7 naval helicopter was operated from both the Invincible -class aircraft carriers and later the helicopter carrier HMS Ocean . The creation of Sea King ASaC7, and earlier AEW.2 and AEW.5 models, came as
5915-605: The first of which first arrived on 25 May 2009. The DRDO proposed a more advanced AWACS with a longer range and with a 360-degree coverage akin to the Phalcon system, based on the Airbus A330 airframe, but given the costs involved there is also the possibility of converting used A320 airliners as well. IAF has plans to develop 6 more Netra AEW&CS based on Embraer EMB-145 platform and another 6 based on Airbus A321 platform. These systems are expected to have an enhanced performance including range and azimuth The Royal Australian Air Force , Republic of Korea Air Force and
6006-418: The foundation for subsequent upgrades including GPS M-Code, Iridium ATC, and Autopilot. USAF DRAGON Production began in 2018. In 2014 the USAF began upgrading block 30/35 E-3B/Cs into block 40/45 E-3Gs. This upgrade replaces the main flight computer with a Red Hat Linux -based system, as well as replacing the DOS 2.0-like operating system with a Windows 95 -like system on the operator workstations. In 2016,
6097-507: The four remaining aircraft upgraded in Riyadh between 2014 and 2016. Between 2000 and 2008 NATO upgraded its E-3s to Mid Term Program (MTP) standard. This involved technical upgrades and a total multi-sensor-systems integration In 2009, the USAF, in cooperation with NATO, entered into a major flight deck avionics modernization program in order to maintain compliance with worldwide airspace mandates. The program, called DRAGON (for DMS Replacement of Avionics for Global Operation and Navigation),
6188-483: The fuselage by 2 struts. It is tilted down at the front to reduce its aerodynamic drag, which lessens its detrimental effect on take-offs and endurance. This tilt is corrected electronically by both the radar and secondary surveillance radar antenna phase shifters . The rotodome uses bleed air , outside cooling doors, and fluorocarbon -based cold plate cooling to maintain the electronic and mechanical equipment temperatures. The hydraulically rotated antenna system permits
6279-431: The latest standard. NATO Airborne Early Warning & Control Program Management Agency (NAPMA) is the preparing and executing authority for the FLEP. FLEP will be combined with the standard planned higher echelon technical maintenance. In March 1977 the 552nd Airborne Warning and Control Wing received the first E-3 aircraft at Tinker AFB , Oklahoma . The 34th and last USAF Sentry was delivered in June 1984. The USAF has
6370-480: The left and right sides of the fuselage and each S-band antenna in the nose and tail. The phased array allows aircraft positions on operator screens to be updated every 2–4 seconds rather than every 10 seconds, as is the case on the rotodome AWACS. ELTA was the first company to introduce an Active Electronically Scanned Array Airborne (AESA) Early Warning Aircraft and implement advanced mission aircraft using efficient, high-performance business jet platforms. In 2003,
6461-410: The most common systems worldwide. Boeing produces a specific system with a " rotodome " rotating radome that incorporates Westinghouse (now Northrop Grumman ) radar. It is mounted on either the E-3 Sentry aircraft ( Boeing 707 ) or more recently the Boeing E-767 ( Boeing 767 ), the latter only being used by the Japan Air Self-Defense Force . When AWACS first entered service it represented
6552-481: The movement of low-flying aircraft, and discriminate, even over land, target aircraft's movements; previously this had been impossible due to the inability to discriminate an aircraft's track from ground clutter . Contracts were issued to Boeing, Douglas , and Lockheed , the latter being eliminated in July 1966. In 1967, a parallel program was put into place to develop the radar, with Westinghouse Electric Corporation and Hughes Aircraft being asked to compete in producing
6643-590: The operational status of its AWACS until 2035 by significantly upgrading fourteen aircraft in the Final Lifetime Extension Program (FLEP) between 2019 and 2026. Upgrades include the expansion of data capacity, expansion of bandwidth for satellite communications, new encryption equipment, new HAVE QUICK radios, upgraded mission computing software and new operator consoles. The supporting ground systems (mission training center and mission planning and evaluation system) will also be upgraded to
6734-607: The opportunity to buy the surplus airframes and use the engines to re-fit the KC-135As used by the Air National Guard and reserve squadrons with the civilian JT3D (designated TF33-PW-102). Over 150 aircraft were modified and the former KC-135A was re-designated the KC-135E. After long service for both airlines and air forces, the number of JT3D-powered aircraft is steadily decreasing. One hundred thirty five KC-135s use
6825-654: The problems with cooling and operator space that existed with the narrower Tu-95 and Tu-116 fuselage. To meet range requirements, production examples were fitted with an air-to-air refueling probe. The resulting system, the Tupolev Tu-126 , entered service in 1965 with the Soviet Air Forces and remained in service until replaced by the Beriev A-50 in 1984. During the Cold war, United Kingdom deployed
6916-520: The radar beam is directed below the horizon. Approval was given on 26 January 1973 for the full-scale development of the AWACS system. To allow further development of the aircraft's systems, orders were placed for three preproduction aircraft, the first of which performed its maiden flight in February 1975. IBM and Hazeltine were selected to develop the mission computer and display system. The IBM computer
7007-540: The radar system on AEW&C aircraft allows the operators to detect, track and prioritize targets and identify friendly aircraft from hostile ones in real-time and from much farther away than ground-based radars. Like ground-based radars, AEW&C systems can be detected and targeted by opposing forces, but due to aircraft mobility and extended sensor range, they are much less vulnerable to counter-attacks than ground systems. AEW&C aircraft are used for both defensive and offensive air operations, and serve air forces in
7098-509: The radar system. In 1968, it was referred to as Overland Radar Technology (ORT) during development tests on the modified EC-121Q. The Westinghouse radar antenna was going to be used by whichever company won the radar competition since Westinghouse had pioneered the design of high-power radio frequency (RF) phase-shifters, which are used to both focus the RF into a pencil beam and scan electronically for altitude determination. Boeing initially proposed
7189-541: The rotodome, single-point ground refueling, air refueling, and a bail-out tunnel or chute. A second bail-out chute was deleted to cut mounting costs. USAF and NATO E-3s have an unrefueled range of 7,400 km (4,600 mi) or 8 hours of flying. The newer E-3 versions bought by France, Saudi Arabia, and the UK are equipped with newer CFM56-2 turbofan engines, and these can fly for about 11 hours or more than 9,250 km (5,750 mi). The Sentry's range and on-station time can be increased through air-to-air refueling and
7280-563: The same radar. The Lockheed WV and EC-121 Warning Star , which first flew in 1949, served widely with US Air Force and US Navy. It provided the main AEW coverage for US forces during the Vietnam war. It remained operational until replaced with the E-3 AWACS. Developed roughly in parallel, N-class blimps were also used as AEW aircraft, filling gaps in radar coverage for the continental US, their tremendous endurance of over 200 hours being
7371-410: The same role as what the combat information center is to naval warships , in addition to being a highly mobile and powerful radar platform. So useful and advantageous is it to have such aircraft operating at a high altitude, that some navies also operate AEW&C aircraft for their warships at sea, either coastal- or carrier-based and on both fixed-wing and rotary-wing platforms. In the case of
7462-562: The selection of Westinghouse's radar for the production aircraft. Hughes' radar was initially thought to be a certain winner due to its related development of the APG-63 radar for the new F-15 Eagle . The Westinghouse radar used a pipelined fast Fourier transform (FFT) to digitally resolve 128 Doppler frequencies, while Hughes's radars used analog filters based on the design for the F-15. Westinghouse's engineering team won this competition by using
7553-665: The system being able to detect low flying formations at a range greater than 100 miles (160 km). US Navy then ordered production of the TBM-3W, the first production AEW aircraft to enter service. TBM-3Ws fitted with the AN/APS-20 radar entered service in March 1945, with 27 eventually constructed. It was also recognised that a larger land-based aircraft would be attractive, thus, under the Cadillac II program, multiple Boeing B-17G Flying Fortress bombers were also outfitted with
7644-578: The two competing radars. As the test beds did not need the same 14-hour endurance demanded of the production aircraft, the EC-137s retained the Pratt & Whitney JT3D commercial engines, and a later reduction in the endurance requirement led to retention of the JT3D engines in production. The first EC-137 made its maiden flight on 9 February 1972, with the fly-off between the two radars taking place from March to July of that year. Favorable test results led to
7735-612: The upgraded Block 40/45 aircraft. In February 1987 the UK and France ordered E-3 aircraft in a joint project which saw deliveries start in 1991. The British requirement arose due to the cancellation of the BAE Nimrod AEW3 project. UK E-3Ds contributed to the NATO Airborne Early Warning and Control Force (NAEWCF), receiving much of their tasking directly from NATO. However, RAF E-3Ds remained UK-crewed and capable of independent, national tasking. In 2009,
7826-568: The whole of Central Europe . AEW&C system indicates close and far proximity range on threats and targets, help extend the range of their sensors, and make offensive aircraft harder to track by avoiding the need for them to keep their own radar active, which the enemy can detect. Systems also communicate with friendly aircraft, vectoring fighters towards hostile aircraft or any unidentified flying object. After having developed Chain Home —the first ground-based early-warning radar detection system—in
7917-418: Was a joint US/NATO development program. RSIP enhances the operational capability of the E-3 radars' electronic countermeasures , and improves the system's reliability, maintainability, and availability. Essentially, this program replaced the older transistor-transistor logic (TTL) and emitter-coupled logic (MECL) electronic components, long-since out of production, with off-the-shelf computers that utilised
8008-492: Was awarded to Boeing and Rockwell Collins in 2010. Drawing on their Flight2 flight management system (FMS), almost all the avionics were replaced with more modern digital equipment from Rockwell Collins. Main upgrades include a Digital Audio Distribution System, Mode-5/ ADS-B transponder, Inmarsat and VDL datalinks, and a terrain awareness and warning system (TAWS). The centerpiece flight deck hardware consists of five 6x8 color graphics displays and two color CDUs. DRAGON laid
8099-670: Was cancelled following the Iranian Revolution . Engineering, test and evaluation began on the first E-3 Sentry in October 1975. Between 1977 and 1992, a total of 68 E-3s were built. Because the Boeing 707 is no longer in production, the E-3 mission package has been fitted into the Boeing E-767 for the Japan Air Self Defense Forces . The E-10 MC2A was intended to replace USAF E-3s—along with
8190-570: Was designated 4PI, and the software was written in JOVIAL . A Semi-Automatic Ground Environment (SAGE) or back-up interceptor control (BUIC) operator would immediately be at home with the track displays and tabular displays, but differences in symbology would create compatibility problems in tactical ground radar systems in Iceland , mainland Europe, and South Korea over Link-11 (TADIL-A) . In 1977, Iran placed an order for ten E-3s, however this order
8281-641: Was in July 2021 with the Sentry subsequently retired from service. In February 1987 the UK and France ordered E-3 aircraft in a joint project which saw deliveries start in 1991. France operates its E-3F aircraft independently of NATO. France operates four aircraft, all fitted with the newer CFM56-2 engines. In early 2024, there were reports that France is looking to the Swedish Saab GlobalEye to replace its AWACS aircraft. Three Boeing E-3D Sentry (Sentry AEW.1) aircraft, acquired second hand from
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