Boeing E-3 Sentry

2025-07-21T16:11:56Z

178.231.107.8: /* Operators */

{{Short description|Airborne early warning and control aircraft based on Boeing 707 airframe}}
{{redir|AWACS|the general term|airborne early warning and control}}
{{good article}}
{{Use American English|date=July 2022}}
{{Use dmy dates|date=March 2023}}
{{Infobox aircraft
| name = E-3 Sentry
| image = File:E-3 Sentry Airborne Warning and Control System (AWACS) conducts a mission.jpg
| image_caption = An E-3 Sentry of the United States Air Force
| alt = Aerial view port view of white jet aircraft in-flight. It has a large disc-like black radar lying horizontally above two convergent struts.
| aircraft_type = [[Airborne early warning and control]] (AEW&C)
| national_origin = United States
| manufacturer = [[Boeing Defense, Space & Security]]
| designer =
| first_flight = EC-137D: 9 February 1972 E-3: 25 May 1976<ref name=Eden_p94>Eden et al 2004, p. 94.</ref>
| introduction = March 1977
| retired = 2021 (RAF)
| status = In service
| primary_user = [[United States Air Force]]
| more_users = [[NATO]] [[Royal Air Force]] (retired) [[Royal Saudi Air Force]]
| produced = 1977–1992
| number_built = 68
| developed_from = [[Boeing 707]]
| variants =
}}

The '''Boeing E-3 Sentry''' is an American [[airborne early warning and control]] (AEW&C) aircraft developed by [[Boeing Defense, Space & Security|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 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 Corporation|Westinghouse Electric]]'s and [[Hughes Aircraft|Hughes]]'s competing radars. Both radars used [[Pulse-Doppler radar|pulse-Doppler technology]], with Westinghouse's design emerging as 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 [[Gulf War|Persian Gulf War]], playing a crucial role of directing [[Coalition of the Gulf War|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 the E-3's radar. In April 2022, the U.S. Air Force announced that the [[Boeing E-7 Wedgetail|Boeing E-7]] is to replace the E-3 beginning in 2027.<ref>{{Cite web |title=Air Force identifies Boeing E-7 as solution to replace the E-3 capability |url=https://www.af.mil/News/Article-Display/Article/3011056/air-force-identifies-boeing-e-7-as-solution-to-replace-the-e-3-capability/ |access-date=March 13, 2023 |date=April 26, 2022 |website=Air Force |language=en-US |archive-date=1 September 2022 |archive-url=https://web.archive.org/web/20220901174256/https://www.af.mil/News/Article-Display/Article/3011056/air-force-identifies-boeing-e-7-as-solution-to-replace-the-e-3-capability/ |url-status=live }}</ref>

==Development==
===Background===
In 1963, the USAF asked for proposals for an Airborne Warning and Control System (AWACS) to replace its [[Lockheed EC-121 Warning Star|EC-121 Warning Stars]], which had served in the [[airborne early warning]] role for over a decade.<ref>Wilson 1998, p. 72.</ref> 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/shoot-down|look down]]", i.e. to detect 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 [[Radar#Clutter|ground clutter]].<ref name=Eden_p92>Eden et al. 2004, p. 92.</ref> Contracts were issued to Boeing, [[Douglas Aircraft Company|Douglas]], and [[Lockheed Corporation|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 the radar system. In 1968, it was referred to as Overland Radar Technology (ORT) during development tests on the modified EC-121Q.<ref name="AUR1">{{cite web |url=http://www.airpower.maxwell.af.mil/airchronicles/aureview/1972/may-jun/pearce.html |title=AWACS to Bridge the Technological Gap |access-date=14 February 2009 |publisher=Air University |archive-url=https://web.archive.org/web/20040627142853/http://www.airpower.maxwell.af.mil/airchronicles/aureview/1972/may-jun/pearce.html |archive-date=27 June 2004 |url-status=dead}}</ref><ref name="Davies p2">Davies 2005, p. 2.</ref> 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.

[[File:Lockheed RC-121C 1955.jpg|thumb|The piston-engined [[Lockheed EC-121 Warning Star|EC-121 Warning Star]], military version of the [[Lockheed Constellation]], saw service in the mid-1950s.|alt=Black-and-white photograph of piston-engined aircraft with a large hump on midfuselage]]
Boeing initially proposed 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 TF34]]s. It would carry its radar in a rotating dome mounted at the top of a forward-swept tail, above the fuselage.<ref name=Eden_p92/><ref>{{cite web|first=Erik|last=Simonsen|url=http://www.boeing.com/news/frontiers/archive/2007/march/i_history.pdf|title=Still keeping watch|date=March 2007|publisher=Boeing|access-date=21 August 2011|archive-url=https://web.archive.org/web/20110629074657/http://www.boeing.com/news/frontiers/archive/2007/march/i_history.pdf|archive-date=29 June 2011|url-status=live}}</ref> Boeing was selected ahead of [[McDonnell Douglas]]'s [[Douglas DC-8|DC-8]]-based proposal in July 1970. Initial orders were placed for two aircraft, designated EC-137D, as test beds to evaluate 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.<ref name="Davies p2"/><ref name="Janes 76 p246">Taylor et al. 1976, p.246</ref>

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.<ref name=AUR1/> Favorable test results led to the selection of Westinghouse's radar for the production aircraft.<ref name="Davies 5-6">Davies 2005, pp. 5–6.</ref> Hughes' radar was initially thought to be a certain winner due to its related development of the [[AN/APG-63 radar family|APG-63]] radar for the new [[McDonnell Douglas F-15 Eagle|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 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 the radar beam is directed below the horizon.<ref name="Northrop1">{{cite web |url=http://www.es.northropgrumman.com/solutions/awacs/assets/AWACS.pdf |title=AWACS Surveillance Radar |access-date=10 February 2009 |publisher=Northrop Grumman |url-status=dead |archive-url=https://web.archive.org/web/20090227021024/http://www.es.northropgrumman.com/solutions/awacs/assets/AWACS.pdf |archive-date=27 February 2009}}</ref>

===Full-scale development===
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 was designated 4PI, and the software was written in [[JOVIAL]]. A [[Semi-Automatic Ground Environment]] (SAGE) or [[Back-Up Interceptor Control|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 [[MIL-STD-6011|Link-11 (TADIL-A)]]. In 1977, Iran placed an order for ten E-3s, however this order was cancelled following the [[Iranian Revolution]].

[[File:First E-3 Sentry at Tinker AFB.jpg|thumb|Welcome ceremony for first E-3 aircraft at [[Tinker AFB]] in 1977|alt=Black-and-white photograph with angled front view of four-engine jet aircraft on ramp with front fuselage door opened: A contingent of people are there to welcome the jet, which has a disc-shaped radar perching on top of struts on the dorsal fuselage.]]
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.<ref name=USAF1>{{cite web|url=https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104504/e-3-sentry-awacs/|title=E-3 SENTRY (AWACS)|access-date=6 September 2017|date=22 September 2015|work=US Air Force|archive-url=https://web.archive.org/web/20170907122425/http://www.af.mil/About-Us/Fact-Sheets/Display/Article/104504/e-3-sentry-awacs/|archive-date=7 September 2017|url-status=live}}</ref><ref name = Boeing1/><ref>{{Cite web |date=2021-05-31 |title=45 years of Boeing E-3 Sentry - a brief history of AWACS — |url=https://afterburner.com.pl/45-years-of-boeing-e-3-sentry-a-brief-history-of-awacs/ |access-date=2024-01-04 |language=en-GB}}</ref>

===Future status===
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 Force]]s. The [[Northrop Grumman E-10 MC2A|E-10 MC2A]] was intended to replace USAF E-3s—along with the [[Boeing RC-135|RC-135]] and the [[E-8 Joint STARS]], but the program was canceled by the [[United States Department of Defense|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.<ref name="NATO summit Warsaw July 2016">NATO summit Warsaw July 2016</ref><ref>{{cite magazine |last=Warnes |first=Alan |date=December 2020 |title=Europe's New Look |magazine=AirForces Monthly |location=Stamford |publisher=Key Publishing|quote=Longer term, NATO is looking to a successor for the AWACS, when it is retired in 2035... the Alliance Future Surveillance and Control (AFSC) programme.}}</ref> 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.<ref>{{cite magazine |last1=Lake |first1=Jon |date=December 2020|title=UK Wedgetail at risk? |magazine=AirForces Monthly |publisher=Key Publishing|quote=Any realistic opportunity to extend the E-3D in service was lost more than a decade ago, when the proposed Project Eagle upgrade was abandoned, and investment in the platform virtually ceased.}}</ref> On 22 March 2019, the UK Defence Secretary announced a $1.98 billion (~${{Format price|{{Inflation|index=US-GDP|value=1980000000|start_year=2019}}}} in {{Inflation/year|US-GDP}}) contract to purchase five [[Boeing E-7 Wedgetail]]s.<ref>{{cite web |url=https://www.raf.mod.uk/news/articles/wedgetail-to-be-rafs-new-early-warning-radar-aircraft/ |title=Wedgetail to be RAF's new early warning radar aircraft |publisher=Royal Air Force |date=22 March 2019 |access-date=22 March 2019 |archive-url=https://web.archive.org/web/20190322111155/https://www.raf.mod.uk/news/articles/wedgetail-to-be-rafs-new-early-warning-radar-aircraft/ |archive-date=22 March 2019 |url-status=live}}</ref> The U.S. Air Force intends to retire 15 of its 31 E-3s and acquire the E-7.<ref>{{cite web |title=US Air Force Picks Boeing E-7 Wedgetail as AWACS Replacement |url=https://www.thedefensepost.com/2022/04/28/usaf-wedgetail-awacs-replacement/ |website=The Defense Post |date=28 April 2022 |access-date=22 May 2022 |archive-date=25 May 2022 |archive-url=https://web.archive.org/web/20220525212143/https://www.thedefensepost.com/2022/04/28/usaf-wedgetail-awacs-replacement/ |url-status=live }}</ref>

On 31 March 2023, the USAF retired an E-3 from service for the first time.<ref>{{cite news |url=https://www.552acw.acc.af.mil/News/Article-Display/Article/3352309/552nd-acw-bids-farewell-to-first-awacs/ |title=552nd ACW Bids Farewell to First AWACS |last1=Bihlajama |first1=Leyinzca |date=6 April 2023 |website=af.mil |publisher=United States Air Force |accessdate=13 April 2023}}</ref>

==Design==
===Overview===
{{See also|Boeing 707#Design|l1=Boeing 707 – Design}}
[[File:ILA 2008 PD 185.JPG|thumb|Close-up rotodome revolving at 6 [[revolutions per minute]].<ref>Wilson 1998, p. 73.</ref>|alt=Close-up view of black disc-shaped radar with wide diagonal white band. The radar rests on 2 convergent struts above aircraft fuselage.]]

The E-3 Sentry's airframe is a modified [[Boeing 707|Boeing 707-320B Advanced]] model. Modifications include a rotating radar dome ([[Radome|rotodome]]), uprated hydraulics from 241 to 345 bar (3500–5000 psi) to drive the rotodome,<ref name="Pete-447">{{cite book|last=Piotrowski|first=General ''Pete''|title=Basic Airman to General: The Secret War & Other Conflicts|page=447|isbn=978-1-4931-6186-7|year=2014|publisher=Xlibris Corporation }}</ref> single-point ground refueling, air refueling, and a bail-out tunnel or chute. A second bail-out chute was deleted to cut mounting costs.<ref name="Cresent1">{{cite book|author=Gunston, Bill|title=The Illustrated Encyclopedia of the World's Modern Military Aircraft|year=1985|publisher=Leisure Books|isbn=978-0-517-22477-9|author-link=Bill Gunston|url-access=registration|url=https://archive.org/details/hitlersluftwaffe0000wood}}</ref>

USAF and NATO E-3s have an unrefueled range of {{cvt|7400|km}} or 8 hours of flying.{{citation needed|date=October 2023}} The newer E-3 versions bought by France, Saudi Arabia, and the UK are equipped with newer [[CFM International CFM56|CFM56-2]] turbofan engines, and these can fly for about 11 hours or more than {{cvt|9250|km}}.<ref>{{cite web|title=Boeing E-3 Airborne Warning and Control System (AWACS)|publisher=Boeing|url=http://www.boeing.com/defense-space/ic/awacs/docs/E-3AWACS_overview.pdf|access-date=22 August 2011|url-status=dead|archive-url=https://web.archive.org/web/20060318165642/http://www.boeing.com/defense-space/ic/awacs/docs/E-3AWACS_overview.pdf|archive-date=18 March 2006}}</ref> The Sentry's range and on-station time can be increased through [[air-to-air refueling]] and 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.<ref name=USAF1/><ref name=Boeing1/>

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 the boundaries of the U.S. or NATO countries and can direct interceptor aircraft to these targets.<ref name=USAF1/> 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.<ref name=USAF1/>

===Avionics===
The unpressurized rotodome is {{cvt|30|feet|m}} in diameter, {{cvt|6|feet|m}} thick at the center, and is held {{cvt|11|feet|m}} above the fuselage by 2 struts.<ref name=USAF1/> 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 shifter]]s. 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 the {{interlanguage link|AN/APY-1|uk|AN/APY-1}} and [[AN/APY-2]] [[passive electronically scanned array]] radar system{{citation needed|date=October 2023}} to provide surveillance from the Earth's surface up into the [[stratosphere]], over land or water.

[[File:ProvideComfortAWACScrew.jpg|thumb|right|Air controllers aboard a US E-3 during [[Operation Provide Comfort]]]]
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.<ref name=USAF1/> 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 the [[National Command Authority (United States)|National Command Authority]] in the U.S. via RC-135 or [[aircraft carrier]] task forces.<ref name=USAF1/>

[[Electrical generator]]s mounted in each of the E-3's four engines provide 1 [[megawatt]] of electrical power required by the aircraft's radars and electronics.{{citation needed|date=December 2020}} 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 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 warfare support measures|electronic support measures]] (ESM), provides a [[Look-down/shoot-down|look down]] capability, to detect, identify, and track low-flying aircraft, while eliminating ground clutter returns.<ref name=USAF1/><ref name="Boeing1">{{cite web |url=http://www.boeing.com/defense-space/ic/awacs/index.html |title=Airborne Warning and Control System (AWACS) |access-date=26 May 2007 |publisher=Boeing |url-status=dead |archive-url=https://web.archive.org/web/20070518151530/http://www.boeing.com/defense-space/ic/awacs/index.html |archive-date=18 May 2007}}</ref><ref name="FAS1">{{cite web |url=http://www.fas.org/programs/ssp/man/uswpns/air/special/e3.html |title=E-3 Sentry (AWACS) |access-date=13 July 2011 |date=23 April 2000 |work=[[Federation of American Scientists]] |archive-url=https://web.archive.org/web/20110619202254/http://www.fas.org/programs/ssp/man/uswpns/air/special/e3.html |archive-date=19 June 2011 |url-status=live}}</ref>

===Upgrades===
[[File:E-3 Sentry system operator of NATO.jpg|thumb|The command & comms consoles.|alt=Inside military aircraft. Two personnel manning communications consoles with wide displays.]]

Between 1987 and 2001, USAF E-3s were upgraded under the "Block 30/35 Modification Program".<ref>{{Cite web |date=March 20, 1996 |title=$346 MILLION REQUESTED FOR AWACS RSIP, BLOCK 30-35 AND EXTEND SENTRY |url=https://insidedefense.com/inside-missile-defense/346-million-requested-awacs-rsip-block-30-35-and-extend-sentry |access-date=November 17, 2020 |website=Inside Defense}}</ref> Enhancements included:
*The installation of ESM and an electronic surveillance capability, for both active and passive means of detection.
*Installation of the Class 2H [[Joint Tactical Information Distribution System]] (JTIDS), which provides rapid and secure communication for transmitting information, including target positions and identification data, to other friendly platforms. This upgraded system allowed the [[Link 16]] military tactical data link capability to be added as part of the Block 30/35 upgrade. Prior versions of the E-3 (NATO/US Standard and 20/25) had the Class 1 (Hughes) JTIDS system which was not [[Link 16]] capable.
*[[Global Positioning System]] (GPS) capability was added.
*Onboard computers and software were overhauled to accommodate the JTIDS Class 2H, [[Link 16]], the new ESM systems and to allow for future enhancements.{{citation needed|date=October 2023}}

====RSIP====
The Radar System Improvement Program (RSIP) was a joint US/NATO development program.<ref name=USAF1/> RSIP enhances the operational capability of the E-3 radars' [[electronic countermeasures]], and improves the system's reliability, maintainability, and availability.<ref name=USAF1/> 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 [[computer]]s that utilised a [[High-level programming language]] instead of [[assembly language]]. Significant improvement came from adding [[pulse compression]] to the pulse-Doppler mode.<ref name=Northrop1/> These hardware and software modifications improve the E-3 radars' performance, providing enhanced detection with an emphasis towards low [[radar cross-section]] (RCS) targets.<ref name=USAF1/>

The RAF had also joined the USAF in adding RSIP to upgrade the E-3's radars. The retrofitting of 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.<ref name=USAF1/><ref name=Boeing3>{{cite web |url=http://www.boeing.com/defense-space/ic/awacs/e3svcww/ukfr.html |title=AWACS For United Kingdom and France |access-date=26 May 2007 |publisher=Boeing |url-status=dead |archive-url=https://web.archive.org/web/20070227082213/http://www.boeing.com/defense-space/ic/awacs/e3svcww/ukfr.html |archive-date=27 February 2007}}</ref> Saudi Arabia began RSIP upgrades in 2013; the first aircraft being upgraded by Boeing in Seattle with the four remaining aircraft upgraded in Riyadh between 2014 and 2016.{{citation needed|date=January 2022}}

====NATO Mid Term Program====
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<ref>{{Cite web |date=12 April 2022 |title=NATO Seeks Industry Input for a Successor to its E-3A Sentry AWACS |url=https://www.overtdefense.com/2022/04/12/nato-seeks-industry-input-for-a-successor-to-its-e-3a-sentry-awacs/ |access-date=26 June 2022 |website=Overt Defense |language=en-CA |archive-date=13 April 2022 |archive-url=https://web.archive.org/web/20220413100027/https://www.overtdefense.com/2022/04/12/nato-seeks-industry-input-for-a-successor-to-its-e-3a-sentry-awacs/ |url-status=live }}</ref>

====DRAGON====
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), 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/[[Automatic Dependent Surveillance–Broadcast|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 the foundation for subsequent upgrades including GPS M-Code, Iridium ATC, and Autopilot. USAF DRAGON Production began in 2018.<ref>{{cite web|url=https://www.af.mil/News/Article-Display/Article/497312/dragon-program-to-improve-aging-e-3/|title=DRAGON program to improve aging E-3|website=af.mil|date=15 September 2014 |access-date=14 April 2018|archive-url=https://web.archive.org/web/20180424235937/http://www.af.mil/News/Article-Display/Article/497312/dragon-program-to-improve-aging-e-3/|archive-date=24 April 2018|url-status=live}}</ref>

====USAF Block 40/45====
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 operating system|DOS]] 2.0-like operating system with a [[Windows 95]]-like system on the operator workstations.<ref>{{Cite journal|last=Chen|first=Ernie|date=1 October 2017|title=The Future of AWACS: Technological Advancement or Technological Relic|url=https://apps.dtic.mil/sti/citations/AD1054654|archive-url=https://web.archive.org/web/20201204185357/https://apps.dtic.mil/sti/citations/AD1054654|url-status=live|archive-date=4 December 2020|language=en|via=Defense Technical Information Center}}</ref> In 2016, 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."<ref>{{cite web|date=December 2016|title=Director, Operational Test and Evaluation FY 2016 Annual Report|url=https://www.dote.osd.mil/Portals/97/pub/reports/FY2016/other/2016DOTEAnnualReport.pdf?ver=2019-08-22-105134-547|access-date=26 November 2020|website=dote.osd.mil|pages=361–363|archive-date=24 October 2021|archive-url=https://web.archive.org/web/20211024133518/https://www.dote.osd.mil/Portals/97/pub/reports/FY2016/other/2016DOTEAnnualReport.pdf?ver=2019-08-22-105134-547|url-status=live}}</ref> This caused a delay of approximately two years.<ref>{{cite web|title=E-3 AWACS Block 40/45 Pushed Back Two Years|url=http://www.defense-aerospace.com/articles-view/release/3/181578/e_3g-awacs-block-40%C2%A745-pushed-back-two-years.html|access-date=27 November 2020|website=www.defense-aerospace.com|archive-date=21 October 2021|archive-url=https://web.archive.org/web/20211021052910/http://www.defense-aerospace.com/articles-view/release/3/181578/e_3g-awacs-block-40%C2%A745-pushed-back-two-years.html|url-status=live}}</ref> 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.<ref>[https://www.flightglobal.com/news/articles/boeing-e-3g-makes-middle-east-combat-debut-419318/ Boeing E-3G makes Middle East combat debut] {{Webarchive|url=https://web.archive.org/web/20151120174217/https://www.flightglobal.com/news/articles/boeing-e-3g-makes-middle-east-combat-debut-419318/ |date=20 November 2015}} – Flightglobal.com, 19 November 2015</ref>

====NATO Final Lifetime Extension Program====
NATO intends to extend the operational status of its AWACS until 2035 by significantly upgrading fourteen aircraft in the ''Final Lifetime Extension Program'' (FLEP) between 2019 and 2026.<ref name="NATO summit Warsaw July 2016"/> 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 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.<ref>{{cite web |url=https://www.raf.mod.uk/news/articles/raf-e-3d-sentry-aircraft-returns-to-the-uk-from-last-operational-mission/ |title=RAF E-3D Sentry aircraft returns to the UK from last operational mission |publisher=Royal Air Force |date=5 August 2021 |access-date=7 March 2023 |archive-date=27 February 2023 |archive-url=https://web.archive.org/web/20230227182446/https://www.raf.mod.uk/news/articles/raf-e-3d-sentry-aircraft-returns-to-the-uk-from-last-operational-mission// |url-status=live }}</ref>

==Operational history==
===United States===
In March 1977 the [[552d Air Control Wing|552nd Airborne Warning and Control Wing]] received the first E-3 aircraft at [[Tinker AFB]], [[Oklahoma]].<ref name=USAF1/> The 34th and last USAF Sentry was delivered in June 1984.<ref name=Boeing_AWACS>{{cite web|title=U.S. and NATO AWACS|publisher=Boeing|url=http://www.boeing.com/defense-space/ic/awacs/e3svcww/usnato.html|access-date=21 August 2011|url-status=dead|archive-url=https://web.archive.org/web/20110814161401/http://www.boeing.com/defense-space/ic/awacs/e3svcww/usnato.html|archive-date=14 August 2011}}</ref> The USAF has 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).<ref name=USAF1/>

E-3 Sentry aircraft were among the first to deploy during [[Operation Desert Shield]], where they established 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.<ref name=V&D_p83>Veronico and Dunn 2004, p. 83.</ref> The data collection capability of the E-3 radar and computer subsystems allowed an entire air war to be recorded for the first time.{{citation needed|date=December 2020}} In addition to providing senior leadership with time-critical information on the actions of enemy forces, E-3 controllers assisted in 38 of the 41 air-to-air kills recorded during the conflict.<ref name=USAF1/><ref name=V&D_p83/>

NATO, UK, French and USAF AWACS played an important role in the air campaign against [[Serbia]] and [[Montenegro]] in the former republic of [[Serbia and Montenegro|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.<ref>{{cite web |url=https://shape.nato.int/resources/21/NATO%20Operations,%201949-Present.pdf |title=NATO's Operations 1949–Present |publisher=NATO |access-date=29 December 2021 |url-status=live|archive-url=https://web.archive.org/web/20160220201228/http://www.shape.nato.int/resources/21/NATO%20Operations,%201949-Present.pdf |archive-date=20 February 2016}}</ref> Over 1,000 aircraft operating from bases in [[Germany]] and [[Italy]] took part in 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.<ref>{{Cite web |title=1999 - Operation Allied Force |url=https://www.afhistory.af.mil/FAQs/Fact-Sheets/Article/458957/1999-operation-allied-force/ |access-date=2024-12-31 |website=Air Force Historical Support Division |language=en-US}}</ref>

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 the upgraded Block 40/45 aircraft.<ref name="block4045">{{cite web
|last = Heusel
|first = Darren
|title = E-3 Block 40/45 deploys to combat theater.. The Wait is Over
|publisher = US Air Force
|date = 20 November 2015
|url = https://www.acc.af.mil/News/Article-Display/Article/660300/e-3-block-4045-deploys-to-combat-theater-the-wait-is-over/
|access-date = 9 March 2021
|archive-date = 27 October 2021
|archive-url = https://web.archive.org/web/20211027201233/https://www.acc.af.mil/News/Article-Display/Article/660300/e-3-block-4045-deploys-to-combat-theater-the-wait-is-over/
|url-status = live
}}</ref>

===United Kingdom===
[[File:Royal Air Force (RAF) E-3D Sentry AEW1 (airborne early warning) aircraft, registration ZH106, taking part in Exercise Taurus Mountain 3, in the skies over North Yorkshire in March 2012 - MOD 45153803 (cropped).jpg|thumb|A [[Royal Air Force]] E-3 Sentry over [[North Yorkshire]]]]

In February 1987 the UK and France ordered E-3 aircraft in a joint project which saw deliveries start in 1991.<ref name="Boeing">{{cite web |url=http://www.boeing.com/defense-space/ic/awacs/e3svcww/ukfr.html |title=AWACS For United Kingdom and France |access-date=26 September 2010 |publisher=Boeing |url-status=dead |archive-url=https://web.archive.org/web/20110327082946/http://www.boeing.com/defense-space/ic/awacs/e3svcww/ukfr.html |archive-date=27 March 2011}}</ref> The British requirement arose due to the cancellation of the [[British Aerospace Nimrod AEW3|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.<ref>{{cite web
| title = InsideAIR 24: Goodbye to the E-3D Sentry AWACS
| website = Royal Air Force
| publisher = UK Ministry of Defence
| url = https://www.raf.mod.uk/news/articles/insideair-24-goodbye-to-the-e-3d-sentry-awacs/
| access-date = 2025-01-21
}}</ref>

In 2009, 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.<ref name="AFM">{{cite magazine |last=Lake |first=Jon |date=December 2020 |title=UK Wedgetail at risk?|magazine=AirForces Monthly |page=75 |location=Stamford, Lincs |publisher=Key Publishing Ltd}}</ref><ref>{{cite web|last=Chuter|first=Andrew|date=8 August 2017|title=Northrop Grumman Awarded Extension for Support of British Sentry Fleet|url=https://www.defensenews.com/air/2016/10/20/northrop-grumman-awarded-extension-for-support-of-british-sentry-fleet/|access-date=27 March 2021|website=Defense News|language=en-US|archive-date=13 March 2023|archive-url=https://web.archive.org/web/20230313154658/https://www.defensenews.com/air/2016/10/20/northrop-grumman-awarded-extension-for-support-of-british-sentry-fleet/|url-status=live}}</ref> ''AirForces Monthly'' reported that by December 2020, just 2 aircraft were available for operations at any one time.<ref name="AFM" /> The [[Strategic Defence and Security Review 2015]] had announced the intention to retain the E-3D fleet until 2035, however in March 2019, the Ministry of Defence announced that the E-3Ds would be replaced by five [[E-7A Wedgetail|E-7 Wedgetails]] from 2023.<ref name="SDSR2015">{{cite web|date=November 2015|title=National Security Strategy and Strategic Defence and Security Review 2015|url=https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/478933/52309_Cm_9161_NSS_SD_Review_web_only.pdf|url-status=live|access-date=27 March 2021|publisher=HM Government|archive-url=https://web.archive.org/web/20151124045941/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/478933/52309_Cm_9161_NSS_SD_Review_web_only.pdf |archive-date=24 November 2015}}</ref><ref>{{cite web|last=Chuter|first=Andrew|date=22 March 2019|title=Britain to buy Wedgetail aircraft in nearly $2 billion deal|url=https://www.defensenews.com/global/europe/2019/03/22/britain-to-buy-wedgetail-aircraft-in-nearly-2-billion-deal/|access-date=27 March 2021|website=Defense News|language=en-US|archive-date=22 March 2019|archive-url=https://archive.today/20190322141712/https://www.defensenews.com/global/europe/2019/03/22/britain-to-buy-wedgetail-aircraft-in-nearly-2-billion-deal/|url-status=live}}</ref> 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]].<ref name="AFM" /><ref>{{cite web|last=Hoyle|first=Craig|date=4 July 2018|title=UK committee urges against Wedgetail selection|url=https://www.flightglobal.com/fixed-wing/uk-committee-urges-against-wedgetail-selection/128704.article|url-status=live|access-date=27 March 2021|website=Flight Global|language=en|archive-url=https://web.archive.org/web/20210416033539/https://www.flightglobal.com/fixed-wing/uk-committee-urges-against-wedgetail-selection/128704.article |archive-date=16 April 2021}}</ref> The [[Integrated Review|2021 Integrated Defence Review]] confirmed a reduced order of three aircraft.<ref>{{cite web|title=Ministry of Defence Integrated Review Command Paper|url=https://www.gov.uk/government/collections/integrated-review-ministry-of-defence|access-date=27 March 2021|website=GOV.UK|language=en|archive-date=14 October 2022|archive-url=https://web.archive.org/web/20221014024431/https://www.gov.uk/government/collections/integrated-review-ministry-of-defence|url-status=live}}</ref> On 27 January 2015, the RAF deployed an E-3D Sentry to Cyprus in support of U.S.-led [[2014 military intervention against ISIS|coalition airstrikes]] against [[Islamic State of Iraq and the Levant|Islamic State]] militants in Iraq and Syria.<ref>[http://www.flightglobal.com/news/articles/raf-sentry-aew-aircraft-deploys-in-support-of-counter-is-408549/ RAF Sentry AEW aircraft deploys in support of counter-IS mission] {{Webarchive|url=https://web.archive.org/web/20150202184920/http://www.flightglobal.com/news/articles/raf-sentry-aew-aircraft-deploys-in-support-of-counter-is-408549/ |date=2 February 2015}} – Flightglobal.com, 2 February 2015</ref> The last operational flight by an RAF E3 Sentry was in July 2021 with the Sentry subsequently retired from service.<ref>{{Cite web |last=Allison |first=George |date=2021-09-29 |title=British E-3D Sentry fleet retires |url=https://ukdefencejournal.org.uk/british-e-3d-sentry-fleet-retires/ |access-date=2024-06-08 |website=ukdefencejournal.org.uk |language=en-GB}}</ref>

===France===
In February 1987 the UK and France ordered E-3 aircraft in a joint project which saw deliveries start in 1991.<ref name="Boeing"/> France operates its E-3F aircraft independently of NATO.<ref name="Boeing2">{{cite web |title=E-3 Specifications (707 Platform) and Worldwide Fleet |url=http://www.boeing.com/defense-space/ic/awacs/e3svcww/e3fleet.html |url-status=dead |archive-url=https://web.archive.org/web/20110327083120/http://www.boeing.com/defense-space/ic/awacs/e3svcww/e3fleet.html |archive-date=27 March 2011 |access-date=26 September 2010 |publisher=Boeing}}</ref> France operates four aircraft, all fitted with the newer CFM56-2 engines.<ref name=Boeing1/>

In early 2024, there were reports that France is looking to the Swedish [[Saab AB|Saab]] [[GlobalEye]] to replace its AWACS aircraft.<ref>{{Cite web |date=2024-01-30 |title=La France veut se tourner vers le Saab GlobalEye suédois pour remplacer ses avions Awacs |url=https://meta-defense.fr/2024/01/30/saab-globaleye-visite-macron-suede/ |access-date=2024-02-01 |website=meta-defense.fr |language=fr-FR}}</ref>

===Chile===
Three Boeing E-3D Sentry (Sentry AEW.1) aircraft, acquired second hand from 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.<ref name=Boeing_AWACS_Chile1>{{cite web|url = https://ukdefencejournal.org.uk/british-e-3d-sentry-awacs-aircraft-to-be-sold-to-chile/|title = British E-3D Sentry 'AWACS' aircraft to sold to Chile|date = 18 January 2022|access-date = 18 January 2022|url-status = live|archive-date = 18 January 2022|archive-url = https://web.archive.org/web/20220118144529/https://ukdefencejournal.org.uk/british-e-3d-sentry-awacs-aircraft-to-be-sold-to-chile/}}</ref><ref name=Boeing_AWACS_Chile2}>{{cite web|url = https://www.flightglobal.com/defence/uk-confirms-e-3d-sentry-sale-to-chilean-air-force/147380.article/|title = UK confirms E-3D Sentry sale to Chilean air force|access-date = 4 February 2022|url-status = live|archive-date = 4 February 2022|archive-url = https://web.archive.org/web/20220204113504/https://www.flightglobal.com/defence/uk-confirms-e-3d-sentry-sale-to-chilean-air-force/147380.article}}</ref>

===NATO===
NATO acquired 18 E-3As and support equipment, with the first aircraft delivered in January 1982.<ref name=Wilson_p75>Wilson 1998, p 75.</ref> 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]].<ref name=Wilson_p75/>

NATO E-3s participated in [[Operation Eagle Assist]] after the [[September 11 attacks]] on the World Trade Center towers and the Pentagon.<ref>{{cite web |url=http://www.e3a.nato.int/eng/html/organizations/humanitarian.htm |title=The history of the TCA Squadron |archive-url=https://web.archive.org/web/20160528225040/http://www.e3a.nato.int/eng/html/organizations/humanitarian.htm |archive-date=28 May 2016 |publisher=NATO AWACS}}</ref> NATO and RAF E-3s participated in the [[2011 military intervention in Libya|military intervention in Libya]].<ref>{{Cite news |title=NATO starts patrolling Libyan air space |newspaper=[[The Australian]] |date=11 March 2011 |url=http://www.theaustralian.com.au/news/world/nato-starts-patrolling-air-space-over-libya/story-e6frg6so-1226019422694 |access-date=22 August 2011 |archive-url=https://web.archive.org/web/20150202163543/http://www.theaustralian.com.au/news/world/nato-starts-patrolling-air-space-over-libya/story-e6frg6so-1226019422694 |archive-date=2 February 2015 |url-status=live}}</ref>

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 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.<ref>{{Cite news |date=2014-09-25 |title=Last AWACS return home from Afghanistan |language=en |publisher=[[NATO]] |url=https://www.nato.int/cps/en/natohq/news_113328.htm |access-date=2023-10-17}}</ref><ref>{{Cite news |last=Hoyle |first=Craig |date=2014-09-29 |title=NATO finishes AWACS commitment to Afghanistan |language=en |publisher=[[FlightGlobal]] |url=https://www.flightglobal.com/nato-finishes-awacs-commitment-to-afghanistan/114627.article |access-date=2023-10-17}}</ref>

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.<ref name=Boeing_AWACS/><ref name="Flight1997">{{cite magazine |date=4–10 June 1997 |title=Military Safety |magazine=[[Flight International]] |page=44 |url=http://www.flightglobal.com/pdfarchive/view/1997/1997%20-%201492.html |access-date=23 August 2011 |archive-url=https://web.archive.org/web/20120309220355/http://www.flightglobal.com/pdfarchive/view/1997/1997%20-%201492.html |archive-date=9 March 2012 |url-status=live}}</ref><ref>{{cite web |url=https://www.keymilitary.com/article/nato-retires-second-e-3a-amarg|title=NATO retires second E-3A to AMARG |date=15 November 2018 |publisher=key military |access-date=26 October 2023}}</ref><ref>{{cite web|url=https://www.dm.af.mil/Media/Photos/igphoto/2002042489|title=NATO E-3A retires at 309 AMARG|publisher=dm.af.mil|access-date=26 October 2023|archive-date=26 October 2023|archive-url=https://web.archive.org/web/20231026191429/https://www.dm.af.mil/Media/Photos/igphoto/2002042489/|url-status=dead}}</ref> 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 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.<ref>{{cite web |url=http://www.e3a.nato.int/eng/html/stories/story_102.htm |title=A historic event – First NATO E-3A aircraft to retire |publisher=NATO |access-date=7 July 2015 |url-status=dead |archive-url= https://web.archive.org/web/20150630121739/http://www.e3a.nato.int/eng/html/stories/story_102.htm |archive-date=30 June 2015}}</ref><ref>{{cite web |url=https://www.dvidshub.net/video/411646/nato-e-3a-arrives-davis-monthan-afb#.VZvF7vlVikq |title=A NATO E-3A Arrives at Davis-Monthan AFB |website=dvidshub.net |access-date=14 April 2018 |archive-url=https://web.archive.org/web/20180414172250/https://www.dvidshub.net/video/411646/nato-e-3a-arrives-davis-monthan-afb#.VZvF7vlVikq |archive-date=14 April 2018 |url-status=live}}</ref>

==Variants==
[[File:Boeing E-3 Sentry LX-N 90454-3.JPG|thumb|NATO E-3s possess LX tail registration,<ref name=Wilson_p75/> as they are registered in Luxembourg. The chin bulge houses a suite of electronic warfare support measures.<ref name=Wilson_p75/>|alt=Four-engined jet aircraft in-flight with landing gear partially extended. A large disc-shaped radar perches on two convergent struts on the aft fuselage.]]

;EC-137D
:2 prototype AWACS aircraft with JT3D engines, 1 fitted with a Westinghouse Electric radar and 1 with a Hughes Aircraft Company radar. Both converted to E-3A standard with TF33 engines.
;E-3A
:Production aircraft with TF33 engines and AN/APY-1 radar, 24 built for USAF (later converted to E-3B standard), total of 34 ordered but the last 9 completed as E-3C.<ref name=Pithere3>Pither 1998, pp. 40–42</ref> One additional aircraft retained by Boeing for testing,<ref name=Pithere3/> 18 built for NATO with TF33 engines and 5 for Saudi Arabia with CFM56 engines.<ref name=Pithere3/>
;KE-3A
:These are not AWACS aircraft but CFM56 powered tankers based on the E-3 design. 8 were sold to Saudi Arabia.<ref name=Pithere3/>
;RE-3A
:Three KE-3 airframes delivered as CFM56–powered strategic reconnaissance aircraft. Systems and external appearance are similar to the USAF’s [[RC-135V/W Rivet Joint]] platform. At least one of the RE-3As has received the extended "hog nose" as fitted to the RC-135.{{citation needed|date=November 2022}}
;E-3B
:USAF Block 30 modification. E-3As with improvements, 24 conversions.<ref name=Pithere3/>

;E-3C
:USAF Block 35 modification. Production aircraft with AN/APY-2 radar, additional electronic consoles and system improvements, ten built.{{citation needed|date=October 2023}}
;JE-3C
:One E-3A aircraft used by Boeing for trials later redesignated E-3C.<ref name=Pithere3/>
;E-3D
:Production aircraft for the RAF to E-3C standard with CFM56 engines and British modifications designated ''Sentry AEW.1'', 7 built.<ref name=Pithere3/> Modifications included the addition of a refueling probe next to the existing boom AAR receptacle, CFM-56 engines, wingtip ESM pods, an enhanced Maritime Surveillance Capability (MSC) offering Maritime Scan-Scan Processing (MSSP), JTIDS and Havequick 2 radios.{{citation needed|date=March 2023}}
;E-3F
:Production aircraft for the French Air and Space Force to E-3C standard with CFM56 engines and French modifications, 4 built.<ref name=Pithere3/>
;E-3G
:USAF Block 40/45 modification.<ref>{{Cite web |title=E-3 Airborne Warning and Control System (AWACS) Block 40/45 |url=https://www.dote.osd.mil/Portals/97/pub/reports/FY2016/af/2016e3awacs.pdf?ver=2019-08-22-105430-263 |access-date=9 August 2024 |website=[[Director, Operational Test and Evaluation]]}}</ref> Includes hardware and software upgrades to improve communications, computer processing power, threat tracking, and others, and automates some previously manual functions. Initial operating capability (IOC) declared in July 2014.<ref>[https://www.tinker.af.mil/News/story/id/123463680/ The wait is over…E-3 Block 40/45 deploys to combat theater] – AF.mil, 18 November 2015</ref> It also removed the 1970 vintage mission computing.<ref>{{Cite web |title=E-3 Sentry (AWACS) |url=https://www.af.mil/About-Us/Fact-Sheets/Display/Article/104504/e-3-sentry-awacs/ |access-date=9 August 2024 |website=U.S. Air Force}}</ref> E-3G(II) Block 40/45 modification that included a glass cockpit modification that reduced the crew size by one, and added a new avionics suite.{{citation needed|date=October 2022}}

==Operators==
[[File:Boeing E-3F Sentry (8).jpg|thumb|Boeing E-3F Sentry of the French Air and Space Force]]
[[File:NATO E3A AWACS Paine Field WA Jul15 DSC8405.jpg|thumb|Boeing E-3A Sentry of the NATO E-3A Component]]
[[File:Royal Saudi Air Force E-3A Sentry.jpg|thumb|Boeing E-3A Sentry of the Royal Saudi Air Force]]

;{{flag|Chile}}: The [[Chilean Air Force]] purchased three retired E-3D Sentry aircraft from the [[Royal Air Force]].<ref>{{cite web |last=Trevithick |first=Joseph |url=https://www.thedrive.com/the-war-zone/43960/chile-has-bought-a-trio-of-retired-e-3d-sentry-radar-planes-from-britain-reports |title=Chile Has Bought A Trio Of Retired E-3D Sentry Radar Planes From Britain: Reports |publisher=Thedrive.com |date=20 January 2022 |accessdate=28 February 2022 |archive-date=22 January 2022 |archive-url=https://web.archive.org/web/20220122180918/https://www.thedrive.com/the-war-zone/43960/chile-has-bought-a-trio-of-retired-e-3d-sentry-radar-planes-from-britain-reports |url-status=live }}</ref><ref>{{Cite web|url=https://www.janes.com/defence-news/news-detail/uk-to-sell-e-3d-to-us-navy-as-doomsday-trainer-aircraft|title=UK to sell E-3D to US Navy as 'Doomsday' trainer aircraft|date=14 June 2021 |access-date=22 January 2022|archive-date=28 February 2022|archive-url=https://web.archive.org/web/20220228150759/https://www.janes.com/defence-news/news-detail/uk-to-sell-e-3d-to-us-navy-as-doomsday-trainer-aircraft|url-status=live}}</ref><ref>{{cite web|url=https://www.avionslegendaires.net/2022/01/actu/la-grande-bretagne-vend-trois-de-ses-ex-awacs-au-chili/|title=La Grande Bretagne vend trois de ses ex-AWACS au Chili|date=22 January 2022|access-date=22 January 2022|archive-date=16 May 2022|archive-url=https://web.archive.org/web/20220516184349/https://www.avionslegendaires.net/2022/01/actu/la-grande-bretagne-vend-trois-de-ses-ex-awacs-au-chili/|url-status=live}}</ref>

;{{flag|France}}: The [[French Air and Space Force]] purchased four E-3F aircraft.
* ''[[Escadron de détection et de contrôle aéroportés 36 Berry]]'' (36th Airborne Detection and Control Squadron "Berry") based at [[Avord Air Base]].<ref>Wilson 1998, p 76.</ref><ref>{{cite web|url=https://www.scramble.nl/orbats/france/airforce|title=Armed Forces Overview – Armée de l'Air|website=scramble.nl|access-date=17 March 2020|archive-date=17 March 2020|archive-url=https://web.archive.org/web/20200317202848/https://www.scramble.nl/orbats/france/airforce|url-status=dead}}</ref>

;{{flag|NATO}}
: 18 E-3 AWACS were purchased – 1 was written off in [[Greece]], 3 were retired from service. Mainly responsible for monitoring European NATO airspace, they have also been deployed outside the area in support of NATO commitments.<ref>The force performed large scale deployments outside its European bases twice, in 2001/2002 (Operation Eagle Assist, Tinker AFB – USA) and in 2011/2014 (Operation Afghan Assist, Mazar-e Sharif base – Afghanistan) {{cite web|url=https://awacs.nato.int/operations/past-operations|title=PAST OPERATIONS|website=awacs.nato.int|access-date=18 March 2020|archive-date=28 April 2022|archive-url=https://web.archive.org/web/20220428051407/https://awacs.nato.int/operations/past-operations|url-status=live}}</ref> The 20 multinational crews<ref>{{cite web|url=https://awacs.nato.int/page5835237.aspx|title=E-3A COMPONENT|website=awacs.nato.int|access-date=18 March 2020|archive-date=8 October 2018|archive-url=https://web.archive.org/web/20181008095936/https://awacs.nato.int/page5835237.aspx|url-status=live}}</ref> are provided by 15 of the 31 NATO member states.<ref>{{cite web|url=https://awacs.nato.int/organisation/participating-nations|title=PARTICIPATING NATIONS|website=awacs.nato.int|access-date=18 March 2020|quote=''Belgium, the Czech Republic, Denmark, Germany, Greece, Hungary, Italy, ... the Netherlands, Norway, Poland, Portugal, Romania, Spain, Turkey ... and the United States of America''|archive-date=1 June 2022|archive-url=https://web.archive.org/web/20220601203350/https://awacs.nato.int/organisation/participating-nations|url-status=live}}</ref>
* NATO Airborne Early Warning and Control Force – E-3A Component.<ref>{{cite web|url=https://awacs.nato.int/|title=Airborne Early Warning and Control Force|website=awacs.nato.int|access-date=17 March 2020|archive-date=14 October 2022|archive-url=https://web.archive.org/web/20221014034539/https://awacs.nato.int/|url-status=live}}</ref> 3 Boeing E-3 Sentries are based at [[NATO Air Base Geilenkirchen|Geilenkirchen]] (Germany), with forward operating bases at [[Konya]] (Turkey), [[Aktion National Airport|Preveza/Aktion]] (Greece) and [[Vincenzo Florio Airport Trapani–Birgi|Trapani/Birgi]] (Italy) and a forward operating location at [[Ørland Municipality|Ørland]] (Norway).<ref>{{cite web|url=https://www.scramble.nl/orbats/NATO|title=Armed Forces Overview – NATO|website=scramble.nl|access-date=17 March 2020|archive-date=3 August 2020|archive-url=https://web.archive.org/web/20200803225457/https://www.scramble.nl/orbats/NATO|url-status=dead}}</ref><ref>{{cite web|url=https://awacs.nato.int/organisation/forward-operating-bases--location|title=FORWARD OPERATING BASES / LOCATIONS|website=awacs.nato.int|access-date=18 March 2020|archive-date=28 April 2022|archive-url=https://web.archive.org/web/20220428052218/https://awacs.nato.int/organisation/forward-operating-bases--location|url-status=live}}</ref>
** Aircrew Training Squadron<ref>{{cite web |url=http://www.e3a.nato.int/eng/html/organizations/aircrew_training_sq.htm |archive-url=https://web.archive.org/web/20161005091546/http://www.e3a.nato.int/eng/html/organizations/aircrew_training_sq.htm |url-status=dead |archive-date=5 October 2016 |title = NATO AWACS Organization – Trainer Cargo Squadron (TCA)}}</ref>
** Flying Squadron 1<ref>{{cite web |url=http://www.e3a.nato.int/eng/html/organizations/sq_1.htm |archive-url=https://web.archive.org/web/20160602204204/http://www.e3a.nato.int/eng/html/organizations/sq_1.htm |url-status=dead |archive-date=2 June 2016 |title = NATO AWACS Organization – Flying Squadron One History and Overview}}</ref>
** Flying Squadron 2<ref>{{cite web |url=http://www.e3a.nato.int/eng/html/organizations/sq_2.htm |archive-url=https://web.archive.org/web/20160612235226/http://www.e3a.nato.int/eng/html/organizations/sq_2.htm |url-status=dead |archive-date=12 June 2016 |title = NATO AWACS Organization – Flying Squadron Two History and Overview}}</ref>
** Flying Squadron 3 – disbanded in 2015<ref>{{cite web |url=http://www.e3a.nato.int/eng/html/organizations/sq_3.htm |archive-url=https://web.archive.org/web/20161005093211/http://www.e3a.nato.int/eng/html/organizations/sq_3.htm |url-status=dead |archive-date=5 October 2016 |title = NATO AWACS Organization – Flying Squadron Three History and Overview}}</ref>

;{{flag|Saudi Arabia}}: The [[Royal Saudi Air Force]] purchased five E-3A aircraft in 1983.<ref>Wilson 1998, pp. 75–76.</ref> In 2004, modifications began to convert KE-3A tankers into RE-3 electronic intelligence gathering aircraft.<ref>Spyflight.co.uk, [https://spyflight.co.uk/aircraft/#Boeing Boeing] {{Webarchive|url=https://web.archive.org/web/20220710122551/https://spyflight.co.uk/aircraft/#Boeing |date=10 July 2022 }}, accessed 2 October 2021.</ref> {{Update inline|date=December 2023}}
* RSAF No. 6 Wing ([[Prince Sultan Air Base]] – [[Al Kharj]])<ref>{{cite web|url=https://www.scramble.nl/orbats/saudi-arabia/airforce|title=Armed Forces Overview – Royal Saudi Air Force|website=scramble.nl|access-date=2 October 2021|archive-date=16 October 2018|archive-url=https://web.archive.org/web/20181016232724/http://www.scramble.nl/orbats/saudi-arabia/airforce|url-status=dead}}</ref>
::''السرب الثامن عشر'' (''al-Sarab al-Ththamin Eshr'' – No. 18 Squadron)
::No. 19 Squadron – RE-3A/B (as well as [[Beechcraft 350 Super King Air|Beechcraft 350ER-ISR]])
::No. 23 Squadron – KE-3A

;{{flagu|United States|size=23px}}: The [[United States Air Force]] has 21 operational E-3s as of June 2024<ref>{{cite web |title=World Air Forces 2024 |url=https://www.flightglobal.com/download?ac=98881 |website=FlightGlobal |access-date=15 June 2024 |archive-url=https://web.archive.org/web/20240613004908/https://www.flightglobal.com/download?ac=98881 |archive-date=13 June 2024 |pages=33 |url-status=live}}</ref>
:[[Tactical Air Command]] 1976–1992
:'''[[Air Combat Command]]''' 1992–present
* [[552d Air Control Wing]] – [[Tinker Air Force Base]], [[Oklahoma]]
::[[960th Airborne Air Control Squadron]] 2001–present ([[NAS Keflavik]], [[Iceland]] 1979–1992)
::[[963d Airborne Air Control Squadron]] 1976–present
::[[964th Airborne Air Control Squadron]] 1977–present
::[[965th Airborne Air Control Squadron]] 1978–1979, 1984–present
::[[966th Airborne Air Control Squadron]] 1976–present
* [[380th Air Expeditionary Wing]] 2002–present [[Al Dhafra Air Base]], United Arab Emirates
::[[968th Expeditionary Airborne Air Control Squadron]] 2013–present ([[Thumrait Air Base]], [[Oman]] 2002–2003)<ref>{{cite web|url=http://www.afhra.af.mil/factsheets/factsheet.asp?id=20166|title=Factsheets : 968 Expeditionary Airborne Air Control Squadron (ACC)|website=www.afhra.af.mil|access-date=4 April 2016|url-status=dead|archive-url=https://web.archive.org/web/20160420045413/http://www.afhra.af.mil/factsheets/factsheet.asp?id=20166|archive-date=20 April 2016}}</ref>
:'''[[Air Force Reserve Command]]'''
* [[513th Air Control Group]] (Associate) – Tinker AFB, Oklahoma
::[[970th Airborne Air Control Squadron]] 1996–present (Personnel only, aircraft loaned by co-located 552nd ACW as needed)<ref>{{cite book |last=International Institute for Strategic Studies |author-link=International Institute for Strategic Studies |date=2018 |title=The Military Balance |page=64 |publisher=Routledge |isbn=978-1857439557}}</ref>
* [[413th Flight Test Group]] – Robins AFB, Georgia
:: [[10th Flight Test Squadron]] – Tinker AFB, Oklahoma 1994–present<ref>{{cite web|url=https://www.scramble.nl/orbats/usaf-central|title=Armed Forces Overview – USAF – Conus – Central|website=scramble.nl|access-date=17 March 2020|archive-date=8 August 2020|archive-url=https://web.archive.org/web/20200808143843/https://www.scramble.nl/orbats/usaf-central|url-status=dead}}</ref>
:'''[[Pacific Air Forces]]'''
* [[3d Wing]] – [[Elmendorf AFB]], [[Alaska]]
::[[962d Airborne Air Control Squadron]] 1986–present
* [[18th Wing]] – [[Kadena AB]], Japan
::[[961st Airborne Air Control Squadron]] 1979–present

=== Former operators ===
;{{flag|United Kingdom}}: The [[Royal Air Force]] purchased seven E-3Ds by October 1987, designated ''Sentry AEW.1'' in British service.<ref name=Wilson_p75/><ref>{{cite web|url=https://www.raf.mod.uk/aircraft/sentry-aew1-e3d/|title=Sentry AEW1 (E-3D) |publisher=RAF.mod |access-date=10 December 2020|archive-date=5 August 2021|archive-url=https://web.archive.org/web/20210805080958/https://www.raf.mod.uk/aircraft/sentry-aew1-e3d/|url-status=live}}</ref> As of December 2020, only three remained in service after one was withdrawn from service in 2009 to be used as spares, two were withdrawn in March 2019 and a further one withdrawn in January 2020.<ref>{{cite web|url=https://www.key.aero/article/raf-halves-sentry-fleet-less-12-months-keyaero-exclusive|title=UK SENTRY FLEET HALVED IN LESS THAN 12 MONTHS|publisher=Key.Aero|date=14 February 2020|access-date=10 December 2020|archive-date=5 December 2021|archive-url=https://web.archive.org/web/20211205043157/https://www.key.aero/article/raf-halves-sentry-fleet-less-12-months-keyaero-exclusive|url-status=live}}</ref><ref>{{cite web |url=https://www.raf.mod.uk/news/articles/wedgetail-to-be-rafs-new-early-warning-radar-aircraft/ |title=Wedgetail to be RAF's new early warning radar aircraft |publisher=Royal Air Force |date=22 March 2019 |access-date=23 March 2019 |archive-url=https://web.archive.org/web/20190322111155/https://www.raf.mod.uk/news/articles/wedgetail-to-be-rafs-new-early-warning-radar-aircraft/ |archive-date=22 March 2019}}</ref> The fleet had been given an out of service date (OSD) of December 2022.<ref>{{cite web |title=Ministry of Defence: The Equipment Plan 2019 to 2029 |url=https://www.nao.org.uk/wp-content/uploads/2020/02/The-Equipment-Plan-2019-to-2029.pdf |publisher=National Audit Office |date=27 February 2020 |access-date=23 May 2020 |archive-date=16 March 2022 |archive-url=https://web.archive.org/web/20220316075110/https://www.nao.org.uk/wp-content/uploads/2020/02/The-Equipment-Plan-2019-to-2029.pdf |url-status=live }}</ref> They formed the E-3D Component of the NATO Airborne Early Warning and Control Force.<ref>{{cite web|url=https://awacs.nato.int/organisation/e3d-component|title=E-3d component|website=awacs.nato.int|access-date=18 March 2020|archive-date=29 April 2022|archive-url=https://web.archive.org/web/20220429151457/https://awacs.nato.int/organisation/e3d-component|url-status=live}}</ref> However, that date was accelerated pursuant to the 2021 defence review and the aircraft made its final flight in U.K. service in August 2021.<ref>{{cite web|url=https://thelincolnite.co.uk/2021/08/raf-e-3d-sentry-returning-to-waddington-after-final-mission/|title=RAF E-3D Sentry returning to Waddington after final mission|date=4 August 2021|access-date=26 September 2021|archive-date=27 January 2022|archive-url=https://web.archive.org/web/20220127200912/https://thelincolnite.co.uk/2021/08/raf-e-3d-sentry-returning-to-waddington-after-final-mission/|url-status=live}}</ref>
* [[RAF Waddington]], [[Lincolnshire]], England
::[[No. 8 Squadron RAF|No. 8 Squadron]]<ref name="RAF">{{cite web |url=https://www.raf.mod.uk/aircraft/e-3d/ |title=E-3D |publisher=Royal Air Force |access-date=23 March 2019 |archive-url=https://web.archive.org/web/20190323221253/https://www.raf.mod.uk/aircraft/e-3d/ |archive-date=23 March 2019}}</ref> (1991–2021)
::[[No. 23 Squadron RAF|No. 23 Squadron]] (1996–2009)<ref>{{cite web |url=http://www.raf.mod.uk/organisation/23squadron.cfm |title=23 Squadron |publisher=Royal Air Force |access-date=23 March 2019 |archive-url=https://web.archive.org/web/20110114184339/http://www.raf.mod.uk/organisation/23squadron.cfm |archive-date=14 January 2011}}</ref>
::[[No. 54 Squadron RAF|No. 54 Squadron]] (Operational Conversion Unit 2005–?)<ref name="RAF"/>
::[[No. 56 Squadron RAF|No. 56 Squadron]] (Operational Evaluation Unit 2008–?)<ref name="RAF"/>

==Incidents and accidents==
[[File:E-3 Sentry LX-N90457 Crash, 14 July 1996.jpg|thumb|LX-N90457, after having overrun the runway at [[Aktion National Airport|Preveza AB]] on 14 July 1996]]

E-3s have been involved in three hull-loss accidents, and one radar antenna was destroyed during RSIP development (see photo under Avionics).
* On 22 September 1995, a U.S. Air Force E-3 Sentry (callsign Yukla 27, serial number 77-0354), [[1995 Alaska Boeing E-3 Sentry accident|crashed shortly after takeoff]] from [[Elmendorf AFB]], Alaska. The plane lost power to both left side engines after ingesting several [[Canada goose|Canada geese]] during takeoff. The aircraft went down about {{cvt|2|mile}} northeast of the runway, killing all 24 crew members on board.<ref>{{cite web|url=http://aviation-safety.net/investigation/cvr/transcripts/cvr_yukla27.php|title=CVR transcript Boeing E-3 USAF Yukla 27–22 SEP 1995|work=Aviation Safety Network|date=16 October 2004|access-date=21 August 2011|archive-url=https://web.archive.org/web/20111012002254/http://aviation-safety.net/investigation/cvr/transcripts/cvr_yukla27.php|archive-date=12 October 2011|url-status=live}}</ref><ref>{{cite web|url=http://www.aewa.org/Yukla27|title=Yukla 27|publisher=Airborne Early Warning Association|access-date=22 August 2011|archive-url=https://web.archive.org/web/20110810104726/http://www.aewa.org/Yukla27/|archive-date=10 August 2011|url-status=live}}</ref>
* On 14 July 1996, a NATO E-3 Sentry (tail number LX-N90457) overran the runway and crashed into a sea wall at Preveza-Aktion Airport in Greece when the pilot attempted to abort takeoff after mistakenly believing that the aircraft had suffered a bird strike. The aircraft overran the runway and struck a sea wall, where it came to a halt. There were no injuries and the aircraft was written off. Investigators could find no evidence that a bird strike and ingestion had occurred.<ref>{{cite web|url=https://aviation-safety.net/database/record.php?id=19960714-0|title=ASN Aircraft accident Boeing E-3A Sentry (707-300B) LX-N90457 Préveza-Aktion Airport (PVK)|last=Ranter|first=Harro|website=aviation-safety.net|access-date=24 September 2019|archive-date=13 May 2021|archive-url=https://web.archive.org/web/20210513151211/https://aviation-safety.net/database/record.php?id=19960714-0|url-status=live}}</ref>
* On 28 August 2009, a U.S. Air Force E-3C Sentry (serial number 83-0008) participating in a Red Flag exercise at [[Nellis Air Force Base]], Nevada experienced a nose gear collapse on landing, resulting in a fire and damaging the aircraft beyond repair. All 32 crew members evacuated safely.<ref>{{cite web|url=https://www.acc.af.mil/News/Article-Display/Article/201478/e-3-damaged-while-landing-at-nellis-afb/|title=E-3 damaged while landing at Nellis AFB|website=Air Combat Command|language=en-US|access-date=8 April 2022|last=Ramey|first=Charles|date=31 August 2009|archive-date=27 October 2021|archive-url=https://web.archive.org/web/20211027200957/https://www.acc.af.mil/News/Article-Display/Article/201478/e-3-damaged-while-landing-at-nellis-afb/|url-status=live}}</ref>

==Specifications (USAF/NATO)==
[[File:AWACS antenna, Airborne Warning and Control System - National Electronics Museum - DSC00416.JPG|thumb|{{interlanguage link|AN/APY-1|uk|AN/APY-1}} antenna array in the [[National Electronics Museum]]]]
[[File:AWACS Line drawing.jpg|right|500px]]

{{Aircraft specs
|ref= : E-3 Sentry (AWACS){{citation needed|date=October 2023}}
|prime units?=kts

|crew=Flight crew: 4 (aircraft commander, pilot, navigator, flight engineer) 
::::Mission crew: 13–19
|capacity=
|length ft=152
|length in=11
|length note=
|span ft=145
|span in=9
|span note=
|height ft=41
|height in=4
|height note=
|wing area sqft=3050
|wing area note=
|aspect ratio=
|airfoil=
|empty weight lb=185000
|empty weight note=
|gross weight lb=344000
|gross weight note=
|max takeoff weight lb=347000
|max takeoff weight note=
|fuel capacity=
|more general=

|eng1 number=4
|eng1 name=[[Pratt and Whitney TF33-PW-100A]]
|eng1 type=[[turbofan]]
|eng1 kw=
|eng1 hp=
|eng1 shp=
|eng1 kn=
|eng1 lbf=21500

|max speed kts=461
|max speed note=
|max speed mach=
|cruise speed kts=
|cruise speed mph=360
|cruise speed note=optimum
|stall speed kts=
|stall speed note=
|never exceed speed kts=
|never exceed speed note=
|minimum control speed kts=
|minimum control speed note=
|range nmi=4000
|range note=
|combat range nmi=
|combat range note=
|ferry range nmi=
|ferry range note=
|endurance=more than 8 hours without refuelling (about 11 hours with CFM56 engine)
|ceiling ft=29000
|ceiling note= minimum
|g limits=
|roll rate=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|wing loading lb/sqft=
|wing loading note=
|fuel consumption lb/mi=
|power/mass=
|thrust/weight=

|more performance=
|avionics=*AN/APS-133 colour weather radar
*Westinghouse Corporation AN/APY-1 or AN/APY-2 passive electronically scanned array radar system
}}
{{clear}}

==See also==
{{Portal|Aviation}}
{{Aircontent
|see also=
|related=
* [[Boeing C-137 Stratoliner|Boeing CT-49]]
* [[Boeing E-767]] – essentially the E-3's systems in a [[Boeing 767]] airframe
* [[Boeing P-8 Poseidon]]
* [[Boeing KC-135 Stratotanker]]

|similar aircraft=
* [[Beriev A-50]]
* [[Beriev A-100]]
* [[Boeing 737 AEW&C]] (E-7 Wedgetail)
* [[EL/M-2075]]
* [[KJ-2000]]
* [[Northrop Grumman E-2 Hawkeye]]
* [[Northrop Grumman E-8 Joint STARS]]

|lists=
* [[List of active United Kingdom military aircraft]]
* [[List of active United States military aircraft]]
* [[List of military electronics of the United States]]
}}

==References==
'''Notes'''
{{Reflist|group=N}}

'''Citations'''
{{Reflist|30em}}

'''Bibliography'''
{{Refbegin}}
* {{Cite magazine|last=Davies|first=Ed|title=AWACS Origins: Brassboard – Quest for the E-3 Radar|magazine=[[Air Enthusiast]]|issue=119, September/October 2005|location=Stamford, Lincs, UK|publisher=Key Publishing|issn=0143-5450|pages=2–6}}
* {{Cite book|editor-last=Eden|editor-first=Paul|title=The Encyclopedia of Modern Military Aircraft|location=London|publisher=Amber Books|year=2004|isbn=1-904687-84-9}}
* {{Cite book|last=Hurturk|first=Kivanc N|title=History of the Boeing 707|publisher=Buchair UK|year=1998|isbn=0-9666368-0-5}}
* {{Cite magazine|last=Lake|first=Jon|title=Aircraft of the RAF – Part 10 Sentry AEW.1|magazine=[[Air International]]|volume= 76|issue= 2, February 2009|location=Stamford, UK|publisher=Key Publishing|pages=44–47}}
* {{Cite book|last=Pither|first=Tony|title=The Boeing 707 720 and C-135|publisher=Air-Britain (Historians)|year=1998|isbn=0-85130-236-X}}
* {{Cite book|editor-last=Taylor|editor-first=John W.R.|editor-link=John W. R. Taylor|title=Jane's All the World's Aircraft 1976–77|location=London|publisher=Macdonald and Jane's|year=1976|isbn=0-354-00538-3}}
* {{Cite book|last1=Veronico|first1=Nick|last2=Dunn|first2=Jim|url=https://books.google.com/books?id=3zz3KLbOvYUC&pg=PA83|title=21st Century U.S. Air Power|location=Grand Rapids, Michigan|publisher=Zenith Imprint|year=2004|isbn=978-0-7603-2014-3}}{{Dead link|date=September 2023 |bot=InternetArchiveBot |fix-attempted=yes }}
* {{Cite book|last=Wilson|first=Stewart|title=Boeing 707, Douglas DC-8, and Vickers VC-10|location=Fyshwick, Australia|publisher=Aerospace Publications|year=1998|isbn=1-875671-36-6}}
{{Refend}}

==External links==
{{Commons category}}
* [https://web.archive.org/web/20070529030617/http://www.raf.mod.uk/equipment/sentry.cfm Royal Air Force E-3 Sentry information]
* [https://web.archive.org/web/20150801004632/http://awacs-spotter.nl/ NATO AWACS-Spotter Geilenkirchen website]
* [http://www.aewa.org/ Airborne Early Warning Association website]

{{Boeing military aircraft}}
{{707 military variants}}
{{US EW aircraft}}
{{USAF system codes}}
{{Authority control}}

[[Category:Aircraft first flown in 1972]]
[[Category:AWACS aircraft]]
[[Category:Boeing aircraft|E-03 Sentry]]
[[Category:Boeing 707]]
[[Category:Northrop Grumman radars|E-03 Sentry]]
[[Category:Quadjets]]
[[Category:1970s United States military reconnaissance aircraft]]
[[Category:1970s United States command and control aircraft]]
[[Category:Low-wing aircraft]]
[[Category:Aircraft with retractable tricycle landing gear]]

Wikipedia - User contributions [en]

Boeing E-3 Sentry