『每日軍事武器鑑賞』－ E-3 Sentry 空中哨兵預警機

克里斯Chris

E-3 Sentry (AWACS)

The E-3 Sentry is an airborne warning and control system (AWACS) aircraft that provides all-weather surveillance, command, control and communications needed by commanders of U.S. and NATO air defense forces. As proven in Desert Storm, it is the premier air battle command and control aircraft in the world today.

The E-3 Sentry is a modified Boeing 707/320 commercial airframe with a rotating radar dome. The dome is 30 feet (9.1 meters) in diameter, six feet (1.8 meters) thick, and is held 11 feet (3.3 meters) above the fuselage by two struts. It contains a radar subsystem that permits surveillance from the Earth's surface up into the stratosphere, over land or water. The radar has a range of more than 200 miles (320 kilometers) for low-flying targets and farther for aerospace vehicles flying at medium to high altitudes. The radar combined with an identification friend or foe subsystem can look down to detect, identify and track enemy and friendly low-flying aircraft by eliminating ground clutter returns that confuse other radar systems.

Other major subsystems in the E-3 are navigation, communications and computers (data processing). Consoles display computer-processed data in graphic and tabular format on video screens. Console operators perform surveillance, identification, weapons control, battle management and communications functions.

The radar and computer subsystems on the E-3 Sentry can gather and present broad and detailed battlefield information. Data is collected as events occur. This includes position and tracking information on enemy aircraft and ships, and location and status of friendly aircraft and naval vessels. The information can be sent to major command and control centers in rear areas or aboard ships. In time of crisis, this data can be forwarded to the National Command Authorities in the United States.

In support of air-to-ground operations, the Sentry can provide direct information needed for interdiction, reconnaissance, airlift and close-air support for friendly ground forces. It can also provide information for commanders of air operations to gain and maintain control of the air battle.

As an air defense system, E-3s can detect, identify and track airborne enemy forces far from the boundaries of the United States or NATO countries. It can direct fighter-interceptor aircraft to these enemy targets.

Experience has proven that the E-3 Sentry can respond quickly and effectively to a crisis and support worldwide military deployment operations. It is a jam-resistant system that has performed missions while experiencing heavy electronic countermeasures.

With its mobility as an airborne warning and control system, the Sentry has an excellent chance of surviving in war. Among other things, the flight path can quickly be changed according to mission and survival requirements. The E-3 can fly a mission profile for more than 8 hours without refueling. Its range and on-station time can be increased through inflight refueling.

The aircraft can be used as a surveillance asset in support of other government agencies during counter drug operations. U.S. Customs Service officers may fly aboard the E-3 Sentry on precoordinated missions to detect smuggling activities.

克里斯Chris

Engineering, test and evaluation began on the first E-3 Sentry in October 1975. In March 1977 the 552nd Airborne Warning and Control Wing (now 552nd Air Control Wing, Tinker Air Force Base, Okla.), received the first E-3s where they are still assigned. Pacific Air Forces has four E-3 Sentries assigned to the 961st Airborne Air Control Squadron (AACS), Kadena Air Base, Japan, and the 962nd AACS, Elmendorf AFB, Alaska. NATO has acquired 18 of the aircraft and support equipment. The first E-3 was delivered to NATO in January 1982. The United Kingdom has seven E-3s and France has four.


The AWACS Test System-3 (TS-3) test aircraft, a militarized 707, has been flying missions since the 1970s. TS-3 is maintained and operated in Seattle by Boeing for the US Air Force and has logged more than 1,000 flights and 6,800 flight hours testing AWACS enhancements such as radar improvements, new sensors, computers and displays.
E-3 Sentry aircraft were among the first to deploy during Operation Desert Shield where they immediately established an around-the-clock radar screen to defend against Iraqi aggression. During Desert Storm, E-3s flew more than 400 missions and logged more than 5,000 hours of on-station time. They provided radar surveillance and control to more than 120,000 coalition sorties. In addition to providing senior leadership with time-critical information on the actions of enemy forces, E-3 controllers assisted in 38 of the 40 air-to-air kills recorded during the conflict. For the first time in the history of aerial warfare, an entire air war has been recorded. This was due to the data collection capability of the E-3 radar and computer subsystems.

Tinker AFB serves as the E-3 main operating base. Besides a full compliment of flightline support, Tinker AFB provides full back-shop support functions and the capability to access depot facilities. Kadena AB, Japan and Elmendorf AFB, Alaska are also permanent operating locations with assigned E-3s and flightline support, but limited back-shop capabilities. The E-3 is constantly deployed all over the world. Support at deployed locations ranges from full flightline support capabilities to bare base operations. However, all have limited back-shop support. A flightline maintenance support contingent is deployed with the aircraft. Back-shop support is normally not deployed.

In March 1996, the Air Force activated an AWACS Reserve Associate Program unit which will perform duties on active-duty aircraft. The unit is assigned to the 507th Operations Group at Tinker.

In December 1978, the NATO Defence Planning Committee decided to acquire a NATO owned Airborne Early Warning air defence capability to provide air surveillance and command and control for all NATO commands. In October 1980, the NATO Airborne Early Warning Force Command was formed with its Headquarters co-located with SHAPE. In addition to the HQ, the Force comprises two operational components, the E-3A Component at Geilenkirchen NATO Air Base, GE, and the E-3D Component at Royal Air Force Waddington, UK; three Forward Operating Bases located in Turkey, Greece and Italy and a Forward Operating Location in Norway. The E-3A Component operates 18 E-3A Airborne Early Warning and Control (AEW&C) aircraft and 3 Boeing 707 Trainer/Cargo aircraft. The E-3D Component operates 6 E-3D AEW&C aircraft. The E-3A Component is funded by 12 nations (Belgium, Canada, Denmark, Germany, Greece, Italy, Luxembourg, the Netherlands, Norway, Portugal, Turkey and the United States) and the NATO E-3A aircraft are manned by integrated, multinational crews from these countries, with the exception of Luxembourg. The E-3D Component represents the United Kingdom s contribution to the Force and its aircraft are manned by RAF personnel. The NAEWF is the largest commonly funded acquisition program undertaken by the Alliance and is the only NATO owned, multinational, operational force which is fully integrated into the command structure. Operational command of the Force is vested in, and collectively exercised by the MNCs through their executive agent, SACEUR, while the Force Commander exercises day-to-day Operational Control over the Force.

克里斯Chris

Service Life
All E-3 AWACS undergo a four year Programmed Depot Maintenance (PDM) cycle. PDM is accomplished on a cyclic calendar basis to correct defects that have been identified as non-correctable by any one modification and are expected to re-occur throughout the life of the weapon system. PDM items generally range from a complete remove or replace to inspect and rework as necessary. The completion of PDM keeps aircraft structurally sound and airworthy. 2018 is last year of E-3 modifications with all but 5 aircraft retired in 2025.
Upgrade and Improvement Efforts

In October 1994, the U.S. Air Force Air Combat Command (ACC), in partnership with the Air Force's Electronic Systems Center (ESC), initiated Extend Sentry, a program to upgrade and extend the life of the US E-3 AWACS fleet through the year 2025. The concept is to fix/replace aircraft systems that are most responsible for high failure rates, high abort rates, high code 3 rates, PDM days, large numbers of maintenance man-hours, and/or have a chronic negative impact on operational capability. The ACC funding strategy has been to prioritize the 66 selected projects (ranging in cost from $300K to $120M) in order of most benefit for dollar spent toward the objective. The FY98 ACC POM applied a "knee of the curve" analysis to determine a minimum funding level.
The AWACS Block 30/35 Modification is an in-progress production and installation program to add ESM, JTIDS, GPS Integrated Navigation, and additional computer processing power to the E-3. Major advantages include 200 times more accurate locations of targets passed via JTIDS (Link 16) and/or Link 11. GPS timing via 1553 bus synchronizes sensors, communications, and processors to common reference.

The AWACS Radar System Improvement Program (RSIP) is a hardware and software modification to the E-3 to improve radar set performance providing enhanced detection of targets, with an emphasis toward those with a low radar cross section (RCS). RSIP utilizes a Pulse Doppler Pulse Compression (PDPC) waveform, increases data sampling rates, increases range and velocity resolution, increases signal integration time, adds new signal processing algorithms to enhance detection sensitivity and unambiguous range determination, and improves radar set monitoring and control. Improved control and processing algorithms tailored to current threat data enhances system electronic counter-countermeasure (ECCM) capabilities. Major advantages include: Increased range against reduced RCS targets to include cruise missiles; Improved electronic counter-counter measures (ECCM) against current threats; Improved radar system reliability and maintainability (R&M); and Improved radar control and maintenance panel (RCMP) with embedded test equipment


The AWACS Combat ID /IFF program includes: (1) the IFF Top Priority program second part, Block 30/35 APX-103B, including scan-to-scan processing for code de-garble improvement, and obtaining aircraft attitude and altitude data via GINS 1553 Bus and (2) replacing the current IFF Transmitter with a new Solid State IFF Transmitter that corrects R,M,&A problems and provides Mode S compatibility. The SS IFF Transmitter is an Extend Sentry "#1 Must Do" item. Classified Combat ID may be POMed via this program but have zero required funding at this time. The IFF Top Priority must be totally in an installation phase by FY00. The SS IFF Transmitter will be acquired as a NATO and US AWACS coordinated (no MOA) Project. NATO will fund the R&D effort in FY00 but is taking a slightly different approach to IFF improvements so minor US design changes may be necessary.

克里斯Chris

AWACS Communications Upgrades includes: Global Broadcast Service (GBS), digital communications system, and Intelligence Broadcast System (IBS). GBS is key to increased flow of ATO, weather and other information warfare data to be received by AWACS and key to moving mission crew to ground in future. The digital communication system is part of the NATO E-3 Mid Term and can result in deleting one or two Communication Technicians from mission crew composition. It is also key to mission recording capability for training and documentation - a top ACC/DO Extend Sentry objective. The IBS will require upgrade of MATT (currently being installed) to JTT for receipt of Broadcast Intelligence. Procurement will not be complete until 2009 at a total acquisition cost of $637.1M, and production and installation of different subprograms are on different schedules.
The AWACS Computer & Display Modernization seeks to replace the E-3旧 "steam driven computer" and is the highest ranked major project in the Extend Sentry priority list. Step 1 installation begins in the fall of 1998 with 1/3 of fleet complete at start of FY00 FYDP in an effort coordinated with NATO. The migration of the E-3 processing system to open system Defense Information Infrastructure Common Operating Environment (DII COE) compliance is as important to the AWACS mission as the RSIP sensor upgrade. The modernization of US AWACS mission computing capability is evolutionary. It旧 goal is to inject crucial technological improvements in two steps. This approach is being used primarily due to funding constraints and the desire to get critical mission capabilities into the hands of the warfighter as soon as possible. The key components delivered to the user in Step 1 include a better target tracker algorithm, more detailed and useful maps, increased use of colors (allowing more and different symbols to be displayed), and an overall improved Human-Computer Interface (HCI) leading to better situational awareness. ATO processing, battle management decision aids, intel data overlays, weather overlays, and other critical software will be adapted from DII COE applications and delivered after the hardware and basic capability is in place. Step 2 of the AWACS mission computing upgrade provides the warfighter with a completely open DII COE compliant computing architecture enabling rapid, low cost delivery of plug and play capability. It involves the removal of the CC-2E computer and the Airborne Operational Computer Program (AOCP) mission software and full migration to DII COE compliance.

克里斯Chris

The proposed AWACS ESM Upgrades includes 4 sub-projects: (1) RF Front End Redesign to remove local oscillator leakage, increase producibility / maintainability, and remove current frequency management for cosite interference (Dem/Val flight in 4Q98/1Q99); (2) Specific Emitter ID provides ability for ESM ID to emitter serial number -key to Blue/Gray and increases correlation to tracks at higher rates than available from primary sensors; (3) Side Lobe Detection Enhancement increases the sensitivity beyond current capabilities such that emitters can be detected without the E-3 in the emitter旧 main beam; and (4) Multiple Platform Geolocation uses the ESM system to passively obtain very rapid and accurate geolocation of emitters. The future ELINT/ESM Joint needs picture is too cloudy to make a major investment decision on this above program at this point.

The AWACS Bistatic UAV Adjunct is a proposed $850M+ acquisition program with prototype in FY08 and completed in 2015. High Altitude Endurance (HAE) Dark Star/Global Hawk UAVs with bistatic receivers for the AWACS radar will expand area coverage of a single E-3 orbit and with the inherent significant signal to interference ratio enhancement provide increased coverage of low RCS targets while operating inside and outside an air defense threat environment. The inclusion of the Bistatic UAV adjunct to the E-3 would allow reduced E-3 operational tempo in some theaters and the ability to cover two major regional conflicts with fewer E-3s. By only carrying the receiver, IFF interrogator and a JTIDS/JCTN transmitter package, the UAV weight limitations can be met (combat ID systems might also be included if weight and size allows). The bistatic UAV would also be able to serve as an adjunct to the E-2, TPS-75 and other air/ground radars. Most important, the Bistatic UAV is a key part of the USAF transition from the E-3 to UAVs and Space for the AWACS mission, with the mission crew on the ground. The Bistatic UAV will be able to serve as the receiver using a satellite as the radar transmitter instead of the E-3. The bistatic UAV is a common link to a reduced E-3 fleet and use of Space for surveillance of large to LO/VLO air vehicles (missiles and aircraft) in the battlespace.


The proposed Mission Crew to Ground program migrates the battle management function off of AWACS to the ground to reduce manpower and cost, centralizes C2 in GTACS, provides room for additional E-3 sensor growth, and provides a transition step to move the majority of AWACS functions from the E-3 to UAVs and Space in the 2025 time frame. This program will allow more sensor growth in volume and weight on-board the E-3 for enhanced surveillance tasks without loss of time on station, and will centralize command and control at AOC/CRC nodes in the TACS using sensor data from AWACS and other sources such as UAVs. AWACS sensor data would be downlinked using LOS and/or SATCOM similar to the ground element of JSTARS today, but using the GBS (AWACS Comm Upgrades) with satellite cross-link capability. Only the Communications Technician, Airborne Radar Technician, and the flight crew stay aboard the E-3) and training savings for the USAF. The cost concept includes four ground stations (CONUS, CONUS backup and two theater deployable). Of a 33 aircraft fleet, only 27 E-3s are converted to a sensor platform configuration. Total acquisition cost is $1.52 Billion.

克里斯Chris

Specifications
Primary Function	Airborne surveillance, command, control and communications
Contractors	Prime: Boeing Aerospace Co. Radar: Northrop Grumman
Power Plant	Four Pratt and Whitney TF33-PW-100A turbofan engines
Thrust	21,000 pounds each engine
Length	145 feet, 6 inches (44 meters)
Wingspan	130 feet, 10 inches (39.7 meters)
Height	41 feet, 4 inches (12.5 meters)
Rotodome	30 feet in diameter (9.1 meters), 6 feet thick (1.8 meters), mounted 11 feet (3.33 meters) above fuselage
Speed	Optimum cruise 360 mph (Mach 0.48)
Ceiling	Above 29,000 feet (8,788 meters)
Maximum Takeoff Weight	347,000 pounds (156,150 kilograms)
Endurance	More than 8 hours (unrefueled)
Unit Cost	Approximately $270 million
Crew	Flight crew of four plus mission crew of 13-19 specialists (mission crew size varies according to mission)
Date Deployed	March 1977
Inventory	Active force, 33; Reserve, 0; Guard, 0
Losses	An E-3 crashed 22 Sep 1995 in Alaska, reducing the US fleet by one.

克里斯Chris

Aircraft ListProduction numberSerial numberTypeOperatorDeliveredComments2051871-01407E-3B552 ACW2051971-01408E-3B552 ACW2104673-01674E-3CBoeing2104775-00556E-3B552 ACW2118573-01675E-3B552 ACW2120775-00557E-3B552 ACW2120875-00558E-3B552 ACW2120975-00559E-3B552 ACW2125075-00560E-3B552 ACW2143476-01604E-3B552 ACW2143576-01605E-3B552 ACW2143676-01606E-3B552 ACW2143776-01607E-3B552 ACW2155177-00351E-3B552 ACW2155277-00352E-3B552 ACW2155377-00353E-3B552 ACW2155477-00354E-3B552 ACWcrashed 22 Sep 95 2155577-00355E-3B552 ACW2155677-00356E-3B552 ACW2175278-00576E-3B552 ACW2175378-00577E-3B552 ACW2175478-00578E-3B552 ACW2175579-00001E-3B552 ACW2175679-00002E-3B552 ACW2175779-00003E-3B552 ACW2282980-00137E-3C552 ACW2283080-00138E-3C552 ACW2283180-00139E-3C552 ACW2283281-00004E-3C552 ACW2283381-00005E-3C552 ACW2283482-00006E-3C552 ACW2283582-00007E-3C552 ACW2283683-00008E-3C552 ACW2283783-00009E-3C552 ACW

克里斯Chris

(文章來自：Ｅ系列）

克里斯Chris

E-3「望樓」，世界上最好的大型預警機，由美國波音公司生產，原型為波音707/320客機。E-3是根據美空軍「空中警戒和控制系統」(AWACS)計劃研製的全天候遠程空中預警和控制飛機，有下視能力，能在各種地形上空監視有人飛機與無人駕駛飛行器。E-3採用四台普惠公司的TF33-PW-100A渦扇發動機，單台推力9534千克。E-3的機身中部上方安裝了一個巨大的雷達天線罩，機內加裝了相關的大量電子設備，使得E-3能作為美軍在作戰戰區中的指揮和通信中心。E-3的研製始於1975年。安裝試驗機編號為EC-137D。1977年3月，美第552空中預警控制中隊接受了首架E-3預警機。美軍全部34架E-3中的最後一架於1984年6月服役。



E-3的一些早期設想方案





50年代美國的防空警戒體系是由地面預警雷達和預警機EC-121組成。60年代初，由於轟炸機速度的提高，低空突防方式的廣泛採用與遠距離空－地導彈的出現，原有防空警戒系統無論從預警距離、預警時間、還是從搜索低空目標的能力來說均已不能滿足需要。從1962年起，美國空軍開始考慮發展新的警戒系統，並研究了這種飛機在戰術空戰中作為空中監控與指揮站的可能性。1963年，美空軍防空司令部與戰術空軍司令部提出對空中警戒和控制系統的要求。1964年，美空軍系統司令部在分析當時的雷達技術水平後開展了「下視雷達技術」計劃。1966年3月簽訂雷達技術鑒定合同，1967年決定採用脈衝多普勒體制，經兩輪對比試飛的篩選，於1973年選取了威斯汀豪斯公司研製的雷達。 　　

「空中警戒和控制系統」的研究合同於1966年4月簽訂，通過方案競爭於1970年選取了波音公司的方案。首先由該公司用波音707-302B型民航機改裝兩架試驗機，用於試驗機載電子設備。試驗機代號為EC-137D，於1972年2月7日首次試飛。首先對比了威斯汀豪斯公司的雷達，然後用3年時間對雷達、數據處理、顯示和通信系統進行了各分系統的樣機驗證試飛與全系統的綜合試飛。隨後又以波音707為基礎研製了3架E-3A的原型機，1975年E-3A的第一架原型機首次試飛，用這些飛機對生產型電子設備進行了飛行試驗。 　　

1977年3月，第一架生產型E-3交付使用。到1978年5月，由首批8架飛機形成了初步作戰能力。到1984年6月，34架E-3(含3架原型機)全部交付完畢。這些飛機在美國本土、歐洲和遠東等地進行過多次演習。按計劃，這些E-3中的1/3駐紮在國外，作為防空警戒與戰術空軍的空中指揮機，其餘駐紮在美國本土，用於本土防空和作為後備力量。目前E-3已被北大西洋公約組織採用，該組織以20億美元的費用引進18架E-3，組成北大西洋公約組織的防空預警系統。由於在設想的歐洲空戰中，飛機密度比美國原設想的高，因此該型須加大目標處理能力，並改裝抗干擾通信系統。

克里斯Chris

The radar dome on the back is the most special part of the E-3 to other aircrafts in appearance. It is 30 feet (9.1 meters) in diameter, six feet (1.8 meters) thick, and held 11 feet (3.3 meters) above the fuselage by two struts. It contains a radar subsystem that permits surveillance from the Earth's surface up into the stratosphere, over land or water. The detect range is more than 200 miles (320 kilometers) for low-flying targets and farther for medium to high altitudes. An identification friend or foe subsystem of the radar can look down to detect, identify and track enemy and friendly low-flying aircraft by eliminating ground clutter returns. In this situation, other types of radars may be confused. The unit cost of the E-3 is approximately $270 million, which is greatly effected by the high price eletronic equipment onboard.

E-3機背上的雷達罩是E-3在外觀上與其他飛機相比最特別的地方。該雷達罩直徑9.1米，厚度1.8米，用兩個支柱支撐在離機身3.3米高處。內部安裝有雷達天線系統，這一雷達系統使E-3能夠提供對大氣層、地面、水面的雷達監視能力。對低空飛行目標，其探測距離達320千米以上，對中空、高空目標探測距離更遠。雷達系統上的敵我識別分系統具有下視能力，並能抗地面雜波干擾。而其他一些雷達在這種條件下無法去除干擾。E-3的單價高達2.7億美元，價格受昂貴的電子設備影響很大。

The variations of E-3 include E-3A, E-3B, E-3C and E-3D. The A type is the first production version for US airforce. A type`s inside is quite different from the prototype, the modified fuselage can hold 17 people. They are 4 pilots, 12 operators and 1 onboard officer. The operators will charge the communication, computer, radar and 9 multi-function display plat. The equipment can be devided into six parts which are radar, IFF, data processing, communication, navigation, data display and control. The radar system includes the Northrop Grumman AN/APY-1 radar, the multi function of the radar can seperate the whole 360 degree area into 32 parts and use different function in each part. Scan once, the IFF system can check over 200 targets with IFF receiver installed, no matter the target is in the air, on the ground or sea.

E-3的主要型別有E-3A、B、C，D四種。EC-137D是用波音707-302B改裝的試驗機，裝4台JT3D-9渦扇發動機，共改裝兩架，其中一架在試飛工作完成後返廠改裝成E-3A生產型。

E-3A為美軍的首批生產型。機艙內作了 很大的改動，改裝後的機艙內可載乘員17名。其中機組4人，系統操縱人員12名，值勤官1名。系統操作人員分別負責操作通信設備、計算機、雷達和9個多用途控制台。機載設備可分成搜索雷達、敵我識別器、數據處理、通信、導航與導引、數據顯示與控制等六個部分。雷達系統有諾斯羅普·格魯曼公司研製的AN/APY-1型S波段脈衝多普勒雷達，可以根據不同的作戰條件把360度方位圓劃分成32個扇形區，分別在每個扇形區內選用恰當的工作方式組合。敵我識別系統在一次掃瞄中能詢問200個以上裝有應答器的空中、海上和陸上目標。

There are some other major subsystems in the E-3, navigation, communications and computers (data processing). The navigation subsystem can offer a total positioning deflection less than 3.7km. The data display and control system is mainly formed of data display, multi-function control plat, eletronic typewriter and assis-display. The data can be showed in original size or zoom to 32 times bigger, the latter is for detect and control fighters to proceed dog-fight mission. The data processing system can record, save and operate the data from the radar, IFF, navigation and other equipment in the aircraft. The system can process 400 targets or 600 for european variations. The operators onboard will look at the consoles display computer-processed data in graphic and tabular format on video screens to check all the information. And the operators will perform surveillance, identification, weapons control, battle management and communications functions.

E-3還有一些其他的重要子系統，包括導航、通信和計算機數據處理系統等。E-3的導航與導引系統可達到綜合導航精度不大於3.7公里。數據顯示和控制系統主要由數據顯示器、多用途控制台、電傳打字機和輔助顯示器組成。顯示有正常與放大32倍兩種倍率，後一種可用於監控和指揮多架戰鬥機的空中格鬥。數據處理系統，能記錄、存儲和處理來自雷達、敵我識別器、通信、導航和引導系統以及其它機載數據搜集和顯示系統的數據。據稱能處理400個不同目標；為適應歐洲的需要，還要把容量加大到600個。機上的操作員通過控制台上的顯示器，以文字或者圖形的多種格式查看各種信息，並做出各種監視、識別、武器控制、戰場管理和通信的操作指令。