EC-121 Warning Star
Encyclopedia
The Lockheed
Lockheed Corporation
The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...

 EC-121 Warning Star
was a United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 and United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 airborne early warning
Airborne Early Warning
An airborne early warning and control system is an airborne radar system designed to detect aircraft at long ranges and control and command the battle space in an air engagement by directing fighter and attack plane strikes...

 radar surveillance aircraft. A military version of the Lockheed Constellation
Lockheed Constellation
The Lockheed Constellation was a propeller-driven airliner powered by four 18-cylinder radial Wright R-3350 engines. It was built by Lockheed between 1943 and 1958 at its Burbank, California, USA, facility. A total of 856 aircraft were produced in numerous models, all distinguished by a...

, it was designed to serve as an airborne early warning system to supplement the Distant Early Warning Line
Distant Early Warning Line
The Distant Early Warning Line, also known as the DEW Line or Early Warning Line, was a system of radar stations in the far northern Arctic region of Canada, with additional stations along the North Coast and Aleutian Islands of Alaska, in addition to the Faroe Islands, Greenland, and Iceland...

, using two large radome
Radome
A radome is a structural, weatherproof enclosure that protects a microwave or radar antenna. The radome is constructed of material that minimally attenuates the electromagnetic signal transmitted or received by the antenna. In other words, the radome is transparent to radar or radio waves...

s, a vertical dome above and a horizontal one below the fuselage. EC-121s were also used for intelligence gathering (SIGINT).

It was introduced in 1954 and retired from service in 1978, although a single specially modified EW aircraft remained in service with the U.S. Navy until 1982. The US Navy versions when initially procured were designated WV-1 (PO-1W), WV-2, and WV-3. Warning Stars of the U.S. Air Force served during the Vietnam War as both electronic sensor
Sensor
A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...

 monitors and as a forerunner to the Boeing E-3 Sentry AWACS. U.S. Air Force aircrews adopted the civil nickname, "Connie" (diminutive of Constellation) as reference, while naval aircrews used the term "Willie Victor" based on a slang version of the phonetic alphabet and the naval version of the aircraft's pre-1962 designation of WV-1, WV-2 or WV-3.

Development

Since 1943 the Lockheed Constellation had been in USAAF service as the C-69
Lockheed C-69 Constellation
The Lockheed C-69 Constellation was the first military version of the Lockheed Constellation aircraft line. It first flew in 1943, and only 22 were ever constructed for the United States Army Air Forces...

. The use of the Constellation by the US Navy for patrol and airborne early warning duties was first investigated in 1949, when the Navy acquired two Lockheed L-749 Constellation
Lockheed L-749 Constellation
-See also:- References :CitationsBibliography* Breffort, Dominique. Lockheed Constellation: from Excalibur to Starliner Civilian and Military Variants. Paris: Histoire and Collecions, 2006. Print. ISBN 2915239622-External Links:...

s. First flown on 9 June 1949, the PO-1W carried large, long-range radars in massive radomes above and below the fuselage. As the radomes produced considerable more side area, the fins of the PO-1W had to be increased. After the PO-1W, which was redesignated WV-1 in 1952, had proved that it was possible to operate large radars on aircraft, the US Navy ordered the WV-2 based on the L-1049 Super Constellation. The WV-1s were later transferred to the Federal Aviation Agency in 1958–1959.

The WV-2/EC-121D was initially fitted with a dorsal AN/APS-45 height finder radar and a ventral AN/APS-20 air search radar. These radars were later upgraded to AN/APS-103 and AN/APS-95 radars, although not simultaneously. The crew commonly numbered 18, six officers (two pilots, two navigators, two weapons controllers) and 12 enlisted personnel (two flight engineers, one radio operator, two crew chiefs, five radar operators, two radar technicians). However, when North Korea shot down a Navy EC-121
EC-121 shootdown incident
The EC-121 shootdown incident occurred on 15 April 1969 when a United States Navy Lockheed EC-121M Warning Star on a reconnaissance mission was shot down by North Korean MiG-17 aircraft over the Sea of Japan...

 in 1969, a crew of 31 was on board.

Orders were placed totaling 142 PO-2W Constellations based on the Lockheed L-1049 Super Constellation
Lockheed L-1049 Super Constellation
The Lockheed L-1049 Super Constellation is an aircraft in the Lockheed Constellation aircraft line. The aircraft was Lockheed's response to the successful Douglas DC-6 airliner and first flew in 1950...

 with deliveries beginning in 1953. The type was redesignated WV-2 in 1954. The WV-2 was familiarly known to its crews as "Willy Victor". In 1962, with standardization of aircraft designations within the Department of Defense
1962 United States Tri-Service aircraft designation system
The 1962 United States Tri-Service aircraft designation system is a unified designation system introduced by the United States Department of Defense on 18 September 1962 for all the U.S. military aircraft. Prior to this date, each armed service used their own nomenclature system...

, the WV-2 then became the EC-121K. A total of 13 of these were converted to WV-2Q electronic intelligence aircraft (which became EC-121M in 1962), and nine were converted to WV-3 weather reconnaissance aircraft (WC-121N in 1962). The EC-121K was also operated by Training Squadron 86 (VT-86)
VT-86
VT-86 'SabreHawks' or Training Squadron 86 is an aircraft training squadron of the United States Navy.-History:Training Squadron EIGHTY-SIX is known by several names: TRARON EIGHTY-SIX, VT-86, or simply the Sabrehawks, a name derived from its history of flying the T-39D/G/N Sabreliner and the TA-4J...

 at NAS Glynco, Georgia for training of Student Naval Flight Officer
Naval Flight Officer
A Naval Flight Officer is an aeronautically designated commissioned officer in the United States Navy or United States Marine Corps that specializes in airborne weapons and sensor systems. NFOs are not pilots per se, but they may perform many "co-pilot" functions, depending on the type of aircraft...

s destined to fly both the EC-121 and the Grumman E-2 Hawkeye. When NAS Glynco was closed and VT-86 transferred to NAS Pensacola, Florida in 1973, the squadron's last EC-121 was also flown to NAS Pensacola for transfer to the collection of the National Museum of Naval Aviation
National Museum of Naval Aviation
The National Museum of Naval Aviation is a military and aerospace museum located at Naval Air Station Pensacola, Florida. The museum opened in 1962....

 where it remains today. A single aircraft became an NC-121K, an electronic warfare
Electronic warfare
Electronic warfare refers to any action involving the use of the electromagnetic spectrum or directed energy to control the spectrum, attack an enemy, or impede enemy assaults via the spectrum. The purpose of electronic warfare is to deny the opponent the advantage of, and ensure friendly...

 variant assigned to Tactical Electronic Warfare Squadron 33 (VAQ-33) at NAS Key West, Florida. This aircraft was the last EC-121 in operational service, flying until 25 June 1982.

The Air Force received 10 RC-121C and 74 EC-121D Warning Stars also based on the L-1049 beginning with diversions from the Navy contracts in October 1953. The 10 RC-121Cs became trainers, designated TC-121C. Between 1966 and 1969, 30 retired Navy EC-121s were transferred to the USAF and converted in EC-121Rs as sensor-monitoring aircraft. Of the 74 EC-121s, 42 were converted to the EC-121H upgrade beginning in 1962, and in 1969, 15 of the remaining EC-121Ds and seven of the EC-121Hs were further upgraded into the final operational variant, the EC-121T, which served as an AWACS prototype in Southeast Asia in 1972. Five EC-121Ds were modified to be broadcasting aircraft for psychological warfare operations, the predecessors of the EC-130 Commando Solo
EC-130 Commando Solo
The Lockheed Martin EC-130 series comprises several slightly different versions of the C-130 that have been and continue to be operated by the U.S. Air Force and, until the 1990s, the U.S...

.

US Navy

WV-2s served from 1956 to 1965 in two "barrier" forces, one off each coast of the North American continent. These barrier forces consisted of five surface picket stations each manned by radar destroyer escorts
Destroyer escort
A destroyer escort is the classification for a smaller, lightly armed warship designed to be used to escort convoys of merchant marine ships, primarily of the United States Merchant Marine in World War II. It is employed primarily for anti-submarine warfare, but also provides some protection...

 and an air wing of WV-2s that patrolled the picket lines at 1,000-4,000 m (3,000-12,000 ft) altitude in six- to 20-hour missions. Their objective was to extend early warning coverage against surprise Soviet bomber and missile attack as an extension of the DEW Line.

The Atlantic Barrier (BarLant) consisted of two rotating squadron detachments, VW-13 and VW-15 home based at NAS Patuxent River, MD. and one squadron, VW-11, permanently based at Naval Station Argentia
Naval Station Argentia
Naval Station Argentia is a former base of the United States Navy that operated from 1941-1994. It was established in the community of Argentia in what was then the Dominion of Newfoundland, which later became the tenth Canadian province .-Construction:Established under the British-U.S...

, Newfoundland
Newfoundland and Labrador
Newfoundland and Labrador is the easternmost province of Canada. Situated in the country's Atlantic region, it incorporates the island of Newfoundland and mainland Labrador with a combined area of . As of April 2011, the province's estimated population is 508,400...

. The mission was to fly orbits to the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...

 and back. There was an AEW Training Unit based at NAS Patuxent River, Maryland. BarLant began operations on 1 July 1956, and flew continuous coverage until early 1965. The Barrier was shifted to cover the approaches between Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...

, Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

, and the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

 (GIUK) barrier in June 1961. Aircraft from Argentia were staged through NAS Keflavik, Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...

, to extend coverage times.

The Pacific Barrier (BarPac) began operations with one squadron operating from NAS Barbers Point
Kalaeloa Airport
Kalaeloa Airport , also called John Rodgers Field and formerly Naval Air Station Barbers Point, is a joint civil-military regional airport of the State of Hawaii established on July 1, 1999 to replace the Ford Island NALF facilities which closed on June 30 of the same year...

, Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

, and a forward refueling base at Naval Station Midway
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...

, on 1 July 1958. Its orbits overlapped the radar picket stations of the ships of Escort Squadron Seven (CORTRON SEVEN), from roughly Kodiak Island
Kodiak Island
Kodiak Island is a large island on the south coast of the U.S. state of Alaska, separated from the Alaska mainland by the Shelikof Strait. The largest island in the Kodiak Archipelago, Kodiak Island is the second largest island in the United States and the 80th largest island in the world, with an...

 to Midway
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...

. Normally four or five WV-2s were required at any single time to provide coverage over the entire line.

Barrier Force operations were discontinued by September 1965 and their EC-121K aircraft placed in storage. However Navy EC-121 operations continued until 1975 in four other squadrons. VQ-1 and VQ-2 operated EC-121M intelligence gathering aircraft at NAF Atsugi, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, and Naval Station Rota, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...

, respectively. VW-4 operated Willy Victors between 1954 and 1975 as Hurricane Hunters
Hurricane Hunters
The Hurricane Hunters are aircraft that fly into tropical cyclones in the North Atlantic Ocean and Northeastern Pacific Ocean for the specific purpose of directly measuring weather data in and around those storms. In the United States, the Air Force, Navy, and NOAA units have all participated in...

, with its primary base at NAS Jacksonville, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 and a forward base at Naval Station Roosevelt Roads, Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

, while its Pacific counterpart, VW-1, flew out of Agana, Guam
Guam
Guam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...

, tracking typhoons. The aircraft was also operated by Training Squadron 86 (VT-86) at NAS Glynco, Georgia for training Student Naval Flight Officers and by Tactical Electronic Warfare Squadron 33 (VAQ-33) for the Fleet Electronic Warfare Systems Group (FEWSG) at NAS Norfolk, Virginia and later at NAS Key West, Florida. At the time of its retirement in the late 1970s, the VAQ-33 aircraft was the last EC-121 operated by the Navy.

US Air Force

The United States Air Force operated three wings of EC-121s between 1954 and 1978, and three separate squadrons. Until the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

, the primary mission of EC-121s was to provide complementary early warning radar coverage to the Pacific and Atlantic barriers by flying orbits 300 miles offshore of the continental United States in what was termed "Contiguous Barriers". Their coverage orbits overlapped those of land-based early warning radars.

Initial deployment of EC-121Cs began with the 551st Airborne Early Warning and Control Wing
551st Electronic Systems Wing
The 551st Electronic Systems Wing is a wing of the United States Air Force whose focus is on 'behind the scenes' electronic work...

, based at Otis Air Force Base, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

. Operational on 21 December 1954, the 551st AEWCW subsequently upgraded to EC-121D and later EC-121H Warning Stars. Its Pacific counterpart was the 552nd AEWCW
552d Air Control Wing
The 552d Air Control Wing is an operational wing of the United States Air Force based at Tinker Air Force Base, Oklahoma. The wing flies the E-3 Sentry aircraft.-History:...

, based at McClellan Air Force Base
McClellan Air Force Base
McClellan Air Force Base is a former United States Air Force base located in the North Highlands area of Sacramento County, northeast of Sacramento, California...

, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

, which became operational on 1 July 1955. After the Cuban Missile Crisis
Cuban Missile Crisis
The Cuban Missile Crisis was a confrontation among the Soviet Union, Cuba and the United States in October 1962, during the Cold War...

 in 1962, the 552nd AEWCW also had administrative control of the 966th AEWCS, based at McCoy Air Force Base
McCoy Air Force Base
With McCoy's closure as an active air force installation in 1975, the site was redeveloped and is known today as Orlando International Airport, which carries the airport code MCO .- History :...

, Florida. The 966th had a dual mission: monitoring activity in Cuban airspace and flying Gold Digger missions (continuous tracks of U-2 surveillance missions).

The third Wing to operate EC-121s was the 553rd Reconnaissance Wing, a Vietnam war organization activated in October 1967 and based in Thailand until its inactivation in December 1970 (See BatCat below). In 1966 Lockheed modified 30 ex-USN Super Constellations (2 EC-121P/WV-3 and 28 EC-121K/WV-2) aircraft to EC-121R for the specialized reconnaissance mission flown by the 553rd. Aircraft were delivered to the wing during the course of 1967. The 553rd RW flew over land and off the coast of Vietnam, over Laos and Cambodia, monitoring and retransmitting low-power signals. Usually they orbited the Ho Chi Minh Trail in eight-hour shifts. As it was expensive to operate and it exposed a large crew to enemy fire it was replaced by a smaller airplane.

As the USAF prepared to deploy the E-3 Sentry in the later 1970s, both the 551st and 552nd AEWCWs phased out EC-121 operations by the end of 1975. All remaining EC-121s were transferred to the Air Force Reserve, which formed the 79th AEWCS at Homestead Air Force Base, Florida in early 1976. The active duty force continued to provide personnel to operate the EC-121s on a 24-hour basis, assigning Detachment 1, 20th Air Defense Squadron to Homestead AFB as associate active duty crews to fly the Reserve-owned aircraft. Besides monitoring Cuban waters, these last Warning Stars also operated from NAS Keflavik, Iceland. Final EC-121 operations ended in September 1978. Detachment 1 was dissolved and 79th AEWCS was re-designated a fighter squadron on 1 October 1978.

In 1967, five EC-121S became operational with the 193rd Tactical Electronic Warfare Squadron
193d Special Operations Wing
The 193d Special Operations Wing is a special operation unit assigned to the Pennsylvania Air National Guard which flies the EC-130J Commando Solo...

 of the Pennsylvania Air National Guard
Pennsylvania Air National Guard
The Pennsylvania Air National Guard is the air force militia of the U.S. state of Pennsylvania. It is, along with the Pennsylvania Army National Guard, an element of the Pennsylvania National Guard. It is considered a part of the United States Air Force, as well as of the state.-Overview:The...

, responsible for psyops missions under project Coronet Solo. From July 1970 to January 1971 they rotated on 30-to-90-day temporary duty deployments to Korat RTAFB, Thailand, under the name Commando Buzz.

Vietnam War

EC-121s were used extensively in Southeast Asia between 16 April 1965, and 1 June 1974, particularly in support of Operation Rolling Thunder
Operation Rolling Thunder
Operation Rolling Thunder was the title of a gradual and sustained US 2nd Air Division , US Navy, and Republic of Vietnam Air Force aerial bombardment campaign conducted against the Democratic Republic of Vietnam from 2 March 1965 until 1 November 1968, during the Vietnam War.The four objectives...

 and Operation Linebacker
Operation Linebacker
Operation Linebacker was the title of a U.S. Seventh Air Force and U.S. Navy Task Force 77 aerial interdiction campaign conducted against the Democratic Republic of Vietnam from 9 May to 23 October 1972, during the Vietnam War....

/Linebacker II
Operation Linebacker II
Operation Linebacker II was a US Seventh Air Force and US Navy Task Force 77 aerial bombing campaign, conducted against targets in the Democratic Republic of Vietnam during the final period of US involvement in the Vietnam War...

 to provide radar early warning and limited airborne control of USAF fighter forces engaging MiG interceptors. Flying orbits over the Gulf of Tonkin
Gulf of Tonkin
The Gulf of Tonkin is an arm of the South China Sea, lying off the coast of northeastern Vietnam.-Etymology:The name Tonkin, written "東京" in Hán tự and Đông Kinh in romanised Vietnamese, means "Eastern Capital", and is the former toponym for Hanoi, the capital of Vietnam...

 and later over Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...

, they were the forerunners of Airborne Early Warning and Control aircraft. The U.S. Navy used a variant,the NC-121 in their Blue Eagle unit from 1965–1972. The Blue Eagles were radar jamming and radio broadcast airplanes. The Blue Eagles were based in Patuxent River MD and were part of oceangraphic squadron VXN-8.

Big Eye


At the onset of Rolling Thunder, the North Vietnamese had an advantage in that their radar coverage could detect most US strike aircraft flying at 5000 feet or above virtually anywhere in the country, using a system that was difficult to jam. US forces countered with radar ships ("Crown") in the Gulf of Tonkin and a ground site at Nakhon Phanom RTAFB, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

, but both systems were line of sight
Line-of-sight propagation
Line-of-sight propagation refers to electro-magnetic radiation or acoustic wave propagation. Electromagnetic transmission includes light emissions traveling in a straight line...

 and had serious gaps in coverage.

To increase coverage the Seventh Air Force
Seventh Air Force
The Seventh Air Force is a numbered air force of the United States Air Force Pacific Air Forces . It is headquartered at Osan Air Base, Republic of Korea....

 (7 AF) requested airborne radar support and the Air Defense Command (redesignated Aerospace Defense Command
Aerospace Defense Command
Aerospace Defense Command is an inactive United States Air Force Major Command. Established in 1946 under the United States Army Air Forces, its mission was to organize and administer the integrated air defense system of the Continental United States , exercise direct control of all active...

 in 1968) was directed to set up the Big Eye Task Force. Five EC-121Ds and 100 support personnel of the 552nd Airborne Early Warning and Control Wing at McClellan Air Force Base
McClellan Air Force Base
McClellan Air Force Base is a former United States Air Force base located in the North Highlands area of Sacramento County, northeast of Sacramento, California...

, California, were deployed to Tainan Air Station, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...

, with four of the EC-121s sent on to a forward operating location at Tan Son Nhut Air Base
Tan Son Nhut Air Base
Tan Son Nhut Air Base was a Republic of Vietnam Air Force facility. It is located near the city of Saigon in southern Vietnam. The United States used it as a major base during the Vietnam War , stationing Army, Air Force, Navy, and Marine units there...

, near Saigon, Republic of Vietnam.

The EC-121s were designed for detection of aircraft flying over water, and ground clutter (spurious signal returns off of terrain features such as mountains) caused interference with their radar pictures. Their crews, however, were experienced in tracking Soviet aircraft over Cuba and had developed a technique whereby an EC-121 flying at 50 to 300 feet could bounce a signal from its bottom-mounted APS-95 Search radar off the surface of the water and detect aircraft at medium altitudes out to 150 miles. Operating in pairs, one Big Eye EC-121 flew a 50-mile race track
Race track
A race track is a purpose-built facility for racing of animals , automobiles, motorcycles or athletes. A race track may also feature grandstands or concourses. Some motorsport tracks are called speedways.A racetrack is a permanent facility or building...

 pattern approximately 30 miles offshore (the Alpha orbit), with the orbit's center at 19°25′N 107°25′E. The second flew a track at 10,000 ft (the Bravo orbit) farther from the coast, acting as a spare for the Alpha EC-121.

This provided a practical detection range of 100 miles, just enough to cover the Hanoi
Hanoi
Hanoi , is the capital of Vietnam and the country's second largest city. Its population in 2009 was estimated at 2.6 million for urban districts, 6.5 million for the metropolitan jurisdiction. From 1010 until 1802, it was the most important political centre of Vietnam...

 urban area and the main MiG base at Phuc Yen. A major disadvantage of this arrangement, however, was that most MiG contacts were beyond the 70-mile range of the Big Eye's APS-45 Height Finder radar, so that they were unable to provide this crucial data to USAF strike forces. Furthermore, technical shortcomings in the EC-121D's systems precluded either controlling a fighter intercept or identifying a specific flight under attack.

The missions from Tan Son Nhut began 21 April 1965, using the call signs Ethan Alpha and Ethan Bravo, which became standard. After refueling at Da Nang
Da Nang
Đà Nẵng , occasionally Danang, is a major port city in the South Central Coast of Vietnam, on the coast of the South China Sea at the mouth of the Han River. It is the commercial and educational center of Central Vietnam; its well-sheltered, easily accessible port and its location on the path of...

 Air Base, Ethan Alpha made a wave-top approach to its orbit station, where it remained five hours. Because of the threat of MiG interception, EC-121s were protected by a MiGCAP
Combat air patrol
Combat air patrol is a type of flying mission for fighter aircraft.A combat air patrol is an aircraft patrol provided over an objective area, over the force protected, over the critical area of a combat zone, or over an air defense area, for the purpose of intercepting and destroying hostile...

 of Lockheed F-104 Starfighters, and if for any reason the MiGCAP could not rendezvous, the EC-121s cancelled their mission. Air conditioning systems aboard the EC-121 were virtually useless in this profile and the heat produced by the electronics, combined with the threat of being shot down, made Alpha orbit missions in particular highly stressful. On 10 July 1965, in its first airborne-controlled interception, an EC-121 provided warning to a pair of US F-4C fighters, resulting in the shooting down of two MiG-17s.

The Big Eye Task Force remained at Tan Son Nhut until February 1967, when the threat of Viet Cong ground attacks prompted a move to Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

.

College Eye

On 1 March 1967, Big Eye was renamed College Eye Task Force and relocated at Ubon RTAFB. Because of the complexity of the aircraft and its systems along with the large support group it required, the CETF was not a welcome tenant at the relatively small Thai bases. It moved to Udon RTAFB
Udon Thani International Airport
Udonthani International Airport is an airport located near the city of Udon Thani in Udon Thani Province in the northeast region of Thailand. It is approximately 280 miles northeast of Bangkok...

 in July and to its final station at Korat RTAFB
Korat Royal Thai Air Force Base
Korat Royal Thai Air Force Base is a base of the Royal Thai Air Force. It is located in northeast Thailand, located approximately 157 miles northeast of Bangkok and about 5 miles south of Nakhon Ratchasima , the second largest city in Thailand.During the Vietnam War, Korat RTAFB was the...

 on 17 October 1967.

From April 1965 to early 1966 and beginning again in late 1967, the EC-121Ds also controlled a flight of MiGCAP fighters for unarmed support aircraft operating over the Gulf. The EC-121Ds also served as an airborne communications relay center for strike aircraft to transmit mission results and position reports to the control center at Da Nang; directed operations of fighter escorts, MiGCAPs, Lockheed C-130 Hercules flare ships, and A-26 strike aircraft along the North Vietnamese-Laotian border; provided radar and navigational assistance for Combat Search and Rescue
Combat search and rescue
Combat search and rescue are search and rescue operations that are carried out during war that are within or near combat zones.A CSAR mission may be carried out by a task force of helicopters, ground-attack aircraft, tankers and an airborne command post...

 missions; and assisted fighters in finding tankers for emergency refueling.

The government of China on 12 May 1966, formally protested an incursion
Incursion
Incursion is a science fiction role playing game created by Richard Tucholka and published by Tri Tac Games in 1992.-Overview:The player characters are humans abducted by alien slave traders...

 by an Republic F-105 Thunderchief pursuing a North Vietnamese MiG it subsequently shot down 25 miles inside Chinese territory. A US board of inquiry recommended that College Eye also monitor the "no-fly zone
No-fly zone
A no-fly zone is a territory or an area over which aircraft are not permitted to fly. Such zones are usually set up in a military context, somewhat like a demilitarized zone in the sky, and usually prohibit military aircraft of a belligerent nation from operating in the region.-Iraq,...

" inside the North Vietnamese border with China, provide alerts to US aircraft nearing the buffer zone, and report border crossing violations by US aircraft. This could not be done from the Gulf and a third orbit, called Ethan Charlie, was created in Laos. After tests in June and August, regular missions began 24 August. There were not enough EC-121s or crews to support three orbits twice daily, so the Laotian orbit was only flown every third day, with Ethan Bravo missions canceled on those days. After 13 October 1966, the Charlie orbit was flown every day and the Bravo orbit suspended altogether. In April 1967, four more EC-121s were deployed, two to Thailand on 29 May, making for a total strength of three College Eyes in Taiwan and six in Thailand.

In April 1967, the Air Force began fitting its entire EC-121 fleet with the QRC-248 IFF
Secondary surveillance radar
Secondary surveillance radar is a radar system used in air traffic control , that not only detects and measures the position of aircraft i.e. range and bearing, but also requests additional information from the aircraft itself such as its identity and altitude...

 transponder
Transponder (aviation)
A transponder is an electronic device that produces a response when it receives a radio-frequency interrogation...

 interrogator. The QRC-248 had been developed to surveil Soviet-export
Export
The term export is derived from the conceptual meaning as to ship the goods and services out of the port of a country. The seller of such goods and services is referred to as an "exporter" who is based in the country of export whereas the overseas based buyer is referred to as an "importer"...

 aircraft flown by the Cuban Air Force
Military of Cuba
The Cuban Revolutionary Armed Forces consist of ground forces, naval forces, air and air defence forces, and other paramilitary bodies including the Territorial Troops Militia , Revolutionary Armed Forces , and Youth Labor Army .The armed forces has long been the...

. The SRO-2 transponders installed in Soviet export MiGs enabled Cuban ground-controlled interception
Ground-controlled interception
Ground-controlled interception an air defense tactic whereby one or more radar stations are linked to a command communications centre which guides interceptor aircraft to an airborne target. This tactic was pioneered during World War II by the Royal Air Force with the Luftwaffe to follow closely...

 radars to identify and control their fighters. A testbed EC-121 called Quick Look had flown with College Eye in January 1967 to test the QRC-248 and found that North Vietnamese MiGs used the same transponder. QRC-248 accurately discriminated MiG radar returns from the myriad returns picked up during a mission, and extended the range of low-altitude detection to more than 175 miles, covering virtually all important North Vietnamese target areas.

By 31 May, all College Eyes had been fitted with QRC-248. The mission of the Bravo orbit was changed from that of a backup for the Alpha orbit to being the primary QRC-248 listener. However College Eye was prohibited by the Joint Chiefs of Staff
Joint Chiefs of Staff
The Joint Chiefs of Staff is a body of senior uniformed leaders in the United States Department of Defense who advise the Secretary of Defense, the Homeland Security Council, the National Security Council and the President on military matters...

 from actively "interrogating" MiG transponders, following a National Security Agency
National Security Agency
The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...

 security policy protecting its "intelligence sources" (of which the QRC-248 was one), and thus was restricted to waiting for North Vietnamese GCI to interrogate its aircraft. QRC-248 began regular use on 21 July 1967, but by then North Vietnam's MiG force, which had suffered serious losses in May, had suspended combat operations.

In the last week of August, however, after a period of intensive training and revision of tactics, the MiGs began to engage US strike forces again, scoring a number of kills. Seventh Air Force finally obtained permission for the Bravo orbit EC-121 to actively interrogate with the QRC-248 on 6 October. By 4 December, its success outweighed any value in flying the Alpha orbit, which was discontinued.

On 1 March 1968, the College Eye call signs were changed to Ethan 01, 02, 03, and 04 in conformity with standard Air Force procedures. Ethan 03 (the Laotian orbit) began "positive control" (airborne direction) of C-130 flare
Flare (countermeasure)
A flare is an aerial infrared countermeasure to counter an infrared homing surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust...

 ship flights and A-26 Invader night interdiction missions along the Ho Chi Minh Trail
Ho Chi Minh trail
The Ho Chi Minh trail was a logistical system that ran from the Democratic Republic of Vietnam to the Republic of Vietnam through the neighboring kingdoms of Laos and Cambodia...

 in Laos
Laos
Laos Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ Sathalanalat Paxathipatai Paxaxon Lao, officially the Lao People's Democratic Republic, is a landlocked country in Southeast Asia, bordered by Burma and China to the northwest, Vietnam to the east, Cambodia to the south and Thailand to the west...

 on 19 April 1968.

The task force was scaled back on 1 July 1968, to four EC-121Ds and the Rivet Top testbed aircraft to allow for the basing of another College Eye detachment at Itazuke AB, Japan. The name of the task force was discontinued on 30 October 1968, when it was redesignated a final time as Detachment 1 (Rotational), 552nd AEWCW. The EC-121 deployments to Southeast Asia were discontinued in June 1970 in the expectation that they would no longer be utilized.

Rivet Top

On 9 August 1967, while the College Eye Task Force was still based at Udon, another prototype EC-121 variation began operations testing new equipment as Detachment 2 of the Tactical Air Warfare Center. Known as Rivet Top, this modified EC-121K (later re-designated EC-121M) carried the QRC-248 newly installed in the College Eye aircraft, but also had electronic interrogators capable of reading two additional Soviet transponders, the SRO-1 and SOD-57. Its electronics were custom-built rather than off-the-shelf. However its most important upgrade was the highly secret "Rivet Gym" installation. This consisted of the addition to the crew of Vietnamese-speaking intelligence specialists who manned four voice communication intercept stations able to monitor all communications between the MiGs and their GCI controllers.

Despite this advantage, the Rivet Top experienced two problems which reduced its effectiveness. Its listeners did not have radar scopes to correlate intercepted conversations with specific flights of MiGs, and thus could not determine which US aircraft might be under attack. Secondly, like QRC-248, Rivet Gym was a Signal Intelligence ("SIGINT") asset of NSA, and subject to even more stringent rules protecting knowledge of its existence. Even when real-time warnings to US aircraft were finally permitted in mid-1972, fighter crews were not made aware of the source of the warnings and because EC-121 radio communications were so poor, mandating the use of a radio relay aircraft that often failed, they tended to disregard the credibility of the source.

The Rivet Top prototype moved to Korat along with the College Eye Task Force in October 1967. Originally scheduled to return to the United States in February 1968, because of its value it remained at Korat until 1969. Flying daily missions through its testing period, it began flying every-other-day missions over the Gulf of Tonkin after 31 March 1968, when Rolling Thunder operations were sharply scaled back. Rivet Gym installations were back-fitted to all College Eye EC-121s by the end of May 1968.

Operation Kingpin

Two EC-121Ds, newly modified with the Southeast Asia Operational Requirement 62 (SEAOR-62) electronics suite but not yet operational as EC-121Ts, were ordered to Korat on 29 October 1970. Under the guise of being field tested, they were accompanied by a C-121G carrying 52 crew members, the most experienced technicians of the 552nd AEWCW, and equipment necessary to maintain the new electronics suite. The SEAOR-62 package was supported by a digital data receiver ground terminal and by radio relay equipment transshipped by separate classified airlift. The EC-121Ts arrived in Thailand from McClellan Air Force Base on 12 November.

The purpose of the deployment was to provide an integrated tactical data display with real-time inputs (similar to the Navy Airborne Tactical Data System
Naval Tactical Data System
Naval Tactical Data System, commonly NTDS, refers to a computerized information processing system developed by the United States Navy in the 1950s and first deployed in the early 1960s for use in combat ships.- Reason for development :...

 equipping E-1B Tracer platforms of Task Force 77
Task Force 77
Task Force 77 has been the aircraft carrier battle/strike force of the Seventh Fleet in the United States Navy since the Seventh Fleet was formed....

) in support of Operation Kingpin
Operation Ivory Coast
Operation Ivory Coast was a failed rescue mission conducted in North Vietnam during the Vietnam War by United States Special Operations Forces and other elements of the U.S. Military....

, a Special Operations
Special operations
Special operations are military operations that are considered "special" .Special operations are typically performed independently or in conjunction with conventional military operations. The primary goal is to achieve a political or military objective where a conventional force requirement does...

 mission to rescue prisoners at Son Tay
Son Tay
Sơn Tây is an urban district and city in Hanoi, the capital of Vietnam. It was the capital of Son Tay province before merging with Ha Dong province in 1965...

 prison. Once at Korat, some equipment was tested for the first time because of emission restrictions in U.S. airspace, and the only available manuals and checklists were notes from early flight tests. Even so, both aircraft were operational by 17 November.

On 20 November 1970, at 22:00 and 22:10, the two Warning Stars, using the call signs Frog 01 and Frog 02 respectively, took off from Korat and took station at the previously established low altitude Alpha orbit over the Gulf of Tonkin, with Frog 02 as a backup standby. The 17-man crews were advised in the air of the nature of the rescue mission and their role to provide MiG warning and to direct Air Force F-4 Phantom CAP intercepts. As Frog 01 began its climb to the higher Bravo orbit, it experienced a ruptured oil line that forced the shutdown of one engine. As planned, Frog 02 became the primary aircraft when Frog 01 made an emergency landing at Danang.

The new equipment failed to function properly aboard Frog 02. The ground receivers at the Kingpin command post in Danang failed to receive data, and the APX-83 IFF
IFF
IFF, Iff or iff may refer to:Technology/Science:* Identification friend or foe, an electronic radio-based identification system using transponders...

 processors would not display aboard the aircraft, despite repeated repairs. Their own radar monitors experienced excessive electronic noise, and the jamming of North Vietnamese radars by nearby EKA-3B Skywarriors hindered efforts of the radar technicians to correct the problems. While unable to provide vectoring information to the F-4s escorting the mission, Frog 02 remained on station and relied on its Rivet Top capability to provide supplementary data.

Disco

In October 1971 North Vietnamese MiGs, operating from forward bases opened after the end of Rolling Thunder, began to attempt intercepts of Boeing B-52 Stratofortress missions in southern Laos. On 20 November, a MiG-21 launched air-to-air missile
Air-to-air missile
An air-to-air missile is a missile fired from an aircraft for the purpose of destroying another aircraft. AAMs are typically powered by one or more rocket motors, usually solid fuelled but sometimes liquid fuelled...

s at a B-52 that evaded them by dropping flares. As a result, Warning Stars of Det. 1 returned to Korat, Thailand, to provide radar support by flying the Laotian orbit again, using the call sign Disco. Seven EC-121Ts, replacement aircraft for the earlier series, were based in Thailand and contained both QRC-248 and Rivet Top electronic suites.

When Operation Linebacker
Operation Linebacker
Operation Linebacker was the title of a U.S. Seventh Air Force and U.S. Navy Task Force 77 aerial interdiction campaign conducted against the Democratic Republic of Vietnam from 9 May to 23 October 1972, during the Vietnam War....

 began on 10 May 1972, Disco was one of two principal GCI radars used by U.S. forces, although it continued to be handicapped by poor radio communications. In addition, its slow-turning radar limited its value as a controller of fighters during MiG engagements, while the size of USAF raids during Linebacker nearly saturated its capabilities. However the improvements made in the systems since 1968 enabled the radar operators to distinguish MiG types, and a color code system for them entered the air operations vernacular: "Red Bandits" (Mig-17
Mikoyan-Gurevich MiG-17
The Mikoyan-Gurevich MiG-17 is a high-subsonic fighter aircraft produced in the USSR from 1952 and operated by numerous air forces in many variants. Most MiG-17 variants cannot carry air-to-air missiles, but shot down many aircraft with its cannons...

s); "White Bandits" (MiG-19
Mikoyan-Gurevich MiG-19
The Mikoyan-Gurevich MiG-19 is a Soviet second-generation, single-seat, twin jet-engined fighter aircraft. It was the first Soviet production aircraft capable of supersonic speeds in level flight. A comparable U.S...

s); "Blue Bandits" (MiG-21
Mikoyan-Gurevich MiG-21
The Mikoyan-Gurevich MiG-21 is a supersonic jet fighter aircraft, designed by the Mikoyan-Gurevich Design Bureau in the Soviet Union. It was popularly nicknamed "balalaika", from the aircraft's planform-view resemblance to the Russian stringed musical instrument or ołówek by Polish pilots due to...

)s, and "Black bandits" (MiGs low on fuel).

On 6 July 1972, as the result of seven F-4 Phantoms shot down in one two-week period, a second Disco track was initiated. Flown near the former Alpha orbit over the Gulf of Tonkin, its purpose was to gain better low-altitude coverage in the Hanoi area. At the end of the month Disco was also integrated into the "Teaball" control center, a highly classified system established to collate all signal intelligence on North Vietnamese air activity gathered by all intelligence sources, including non-military. Disco was used as a conduit through which warnings and control vectors were given, but the delay in Teaball acquiring and relaying the information through Disco (which often had to use an unreliable radio relay KC-135A Combat Lightning aircraft operating under the call sign Luzon) cancelled out its value for use in "real time", and the fact that its existence was kept from US air crews damaged its credibility.

On 15 August 1973, Disco EC-121s flew their final combat mission, and on 1 June 1974, Detachment 1 was permanently withdrawn from Southeast Asia. Between 1965 and 1973, the EC-121s flew 13,921 combat missions; more than 98,000 accident-free flying hours, assisted in the shoot-down of 25 MiGs and supported the rescue of 80 downed flyers. No Big Eye, College Eye, or Disco aircraft were lost.

Batcat

During the Vietnam War
Vietnam War
The Vietnam War was a Cold War-era military conflict that occurred in Vietnam, Laos, and Cambodia from 1 November 1955 to the fall of Saigon on 30 April 1975. This war followed the First Indochina War and was fought between North Vietnam, supported by its communist allies, and the government of...

  some 30 EC-121s were modified from U.S. Navy WV-2 and WV-3 early warning Constellations for use with ground sensors to detect enemy troop movements along the Ho Chi Minh Trail
Ho Chi Minh trail
The Ho Chi Minh trail was a logistical system that ran from the Democratic Republic of Vietnam to the Republic of Vietnam through the neighboring kingdoms of Laos and Cambodia...

, and 25 were deployed to Southeast Asia, at Korat Royal Thai Air Force Base
Korat Royal Thai Air Force Base
Korat Royal Thai Air Force Base is a base of the Royal Thai Air Force. It is located in northeast Thailand, located approximately 157 miles northeast of Bangkok and about 5 miles south of Nakhon Ratchasima , the second largest city in Thailand.During the Vietnam War, Korat RTAFB was the...

, as a part of Operation Igloo White
Operation Igloo White
Operation Igloo White was a covert United States Air Force electronic warfare operation conducted from late January 1968 until February 1973, during the Vietnam War. This state-of-the-art operation utilized electronic sensors, computers, and communications relay aircraft in an attempt to automate...

. The resulting EC-121R configuration was nicknamed the Batcat. Two Batcats were lost during the war, with the loss of 22 crewmen, one in a takeoff accident during a thunderstorm on 25 April 1969, the other on 6 September 1969, in a landing accident. Four Thai civilians on the ground were also killed in the second crash.

Batcat EC-121s were camouflaged in the standard three-color Southeast Asia scheme while the College Eye/Disco early warning aircraft were not. BatCat missions were 18 hours in length, with eight hours on station at one of 11 color-coded orbits used during their five-year history, three of which were over South Vietnam, six over Laos, one over Cambodia, and one over the Gulf of Tonkin.

EC-121Rs were operated by the 553rd and 554th Reconnaissance Squadrons of the 553rd Reconnaissance Wing, between 19 October 1967 and 15 December 1970, with approximately 20 Batcats on hand at any one time. The Wing was inactivated 15 December 1970, and the 554th RS relocated to Nakhon Phanom RTAFB to fly QU-22 sensor monitors nicknamed "Baby Bats". Initially with 11 aircraft, the 553rd RS continued operations for another year, gradually returning aircraft and crews to the United States. The final Batcat mission was flown 5 December 1971. The last remaining administrative and support personnel returned to Otis Air Force Base, Massachusetts
Massachusetts
The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

, in January 1972.

Variants


U.S. Navy variants
WV-1: Two prototypes, L-749A Constellation, designated PO-1W before 1952
EC-121K (WV-2): Main USN variant, designated PO-2W before 1952; 244 ordered, 142 produced (the rest went to the USAF).
JC-121K: One modified EC-121K used as a U.S. Army avionics testbed
NC-121K: Unknown number modified as special mission aircraft
YEC-121K: One modified avionics testbed
EC-121L (WV-2E): One modified WV-2, testbed for rotating radar dome with an AN/APS-70 radar
EC-121M (WV-2Q): Electronic intelligence collection variant, 13 modified WV-2
WC-121N (WV-3): Weather reconnaissance variant, eight modified WV-2
EC-121P: Unknown number modified from EC-121K as anti-submarine variant
JEC-121P: Three EC-121P used by the USAF
U.S. Air Force variants
RC-121C: 10 produced, initial USAF variant
JC-121C: Two converted from C-121C and one TC-121C as avionics testbeds
TC-121C: Nine RC-121C modified before 1962 as crew trainers
EC-121D: 73 produced 1953-55 as main USAF variant and one converted from C-121C, originally designated RC-121D
EC-121D Quick Look: One testbed for QRC-248 IFF transponder interrogator
EC-121H: 42 USAF upgrades in 1962, 35 EC-121D and seven WV-2s transferred from the Navy
EC-121J: Two USAF EC-121D modified with upgraded electronics
EC-121M Rivet Top: One EC-121D testbed for Rivet Gym cryptologic linguist electronics suite, originally designated EC-121K
EC-121Q: Four EC-121D modified with upgraded electronics for USAF Gold Digger missions
EC-121R: 30 EC-121K / EC-121P transferred to USAF in 1966–1967 and converted to Batcat sensor signal processor
EC-121S: Five converted for Pennsylvania Air National Guard
Pennsylvania Air National Guard
The Pennsylvania Air National Guard is the air force militia of the U.S. state of Pennsylvania. It is, along with the Pennsylvania Army National Guard, an element of the Pennsylvania National Guard. It is considered a part of the United States Air Force, as well as of the state.-Overview:The...

 from USAF C-121 transports
EC-121T: Final USAF variant. 22 T's were converted from 15 EC-121D and seven EC-121H. One is on display at Peterson Air and Space Museum
Peterson Air and Space Museum
Peterson Air and Space Museum is located inside Peterson Air Force Base, Colorado Springs, Colorado. Access to the museum is limited due to security concerns, so tour groups should contact the museum curator...

.
XW2V-1: Proposed naval development with new features such as four Allison T56-A8 turboprop engines, L-1649A Starliner wings and Bomarc missiles for defense. None built. Was designated L-084 due to the large differences from its predecessors.

United States Air Force

  • 551st AEWCW
    551st Electronic Systems Wing
    The 551st Electronic Systems Wing is a wing of the United States Air Force whose focus is on 'behind the scenes' electronic work...

     - Otis AFB, Massachusetts
    • 960th AEWCS
      960th Airborne Air Control Squadron
      The 960th Airborne Air Control Squadron is part of the 552d Air Control Wing at Tinker Air Force Base, Oklahoma. It operates the E-3 Sentry aircraft conducting airborne command and control missions.-Mission:...

    • 961st AEWCS
      961st Airborne Air Control Squadron
      The 961st Airborne Air Control Squadron is part of the 18th Wing at Kadena Air Base, Japan. It operates the E-3 Sentry aircraft conducting airborne command and control missions.-Mission:...

    • 962d AEWCS
      962d Airborne Air Control Squadron
      The 962d Airborne Air Control Squadron is part of the 3rd Wing at Elmendorf Air Force Base, Alaska. It operates the E-3 Sentry aircraft conducting airborne command and control missions.-Mission:...

  • 552d AEWCW
    552d Air Control Wing
    The 552d Air Control Wing is an operational wing of the United States Air Force based at Tinker Air Force Base, Oklahoma. The wing flies the E-3 Sentry aircraft.-History:...

     - McClellan AFB, California
    • 963d AEWCS
      963d Airborne Air Control Squadron
      The 963d Airborne Air Control Squadron is a squadron of the United States Air Force based at Tinker Air Force Base, Oklahoma. The squadron is a subordinate unit of the 552nd Air Control Wing and it flies the E-3 Sentry, radar surveillance aircraft...

    • 964th AEWCS
      964th Airborne Air Control Squadron
      The 964th Airborne Air Control Squadron is part of the 552d Air Control Wing at Tinker Air Force Base, Oklahoma. It operates the E-3 Sentry aircraft conducting airborne command and control missions.-Mission:...

    • 965th AEWCS
      965th Airborne Air Control Squadron
      The 965th Airborne Air Control Squadron is part of the 552d Air Control Wing at Tinker Air Force Base, Oklahoma. It operates the E-3 Sentry aircraft conducting airborne command and control missions.-Mission:...

  • 553d RW - Korat RTAFB, Thailand
    • 553d RS
    • 554th RS
  • 966th AEWCS
    966th Airborne Air Control Squadron
    The 966th Airborne Air Control Squadron is part of the 552d Air Control Wing at Tinker Air Force Base, Oklahoma. It operates the E-3 Sentry aircraft conducting airborne command and control missions.-Mission:...

     - McCoy AFB, Florida
  • Det. 1, 20th ADS - Homestead AFB, Florida
  • 79th AEWCS
    79th Air Refueling Squadron
    The 79th Air Refueling Squadron is a unit part of the USAF, belonging to the 349th Air Mobility Wing at Travis Air Force Base, California...

     (AFRES) - Homestead AFB, Florida
  • 193d TEWS
    193d Special Operations Wing
    The 193d Special Operations Wing is a special operation unit assigned to the Pennsylvania Air National Guard which flies the EC-130J Commando Solo...

     (ANG) - Olmsted Air Force Base
    Olmsted Air Force Base
    Harrisburg Air National Guard Base is a United States Air Force base, located at Harrisburg International Airport, Pennsylvania. It is located west-southwest of Middletown, Pennsylvania....

    , Pennsylvania
    Pennsylvania
    The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to...


United States Navy

  • AEW Wing Atlantic - NAS Patuxent River, Maryland
    • VXN-8 - NAS Patuxent River, Maryland
    • VW-2 (BarLant) -NAS Patuxent River, Maryland
    • VW-4 ("Hurricane Hunters") - NAS Jacksonville, Florida
    • VW-11 (BarLant) - NAS Argentia, Newfoundland / NAS Patuxent River, Maryland
    • VW-13 (BarLant) - NAS Patuxent River, Maryland / NS Argentia, Newfoundland
    • VW-15 (BarLant) - NAS Argentia, Newfoundland / NAS Patuxent River, Maryland
    • Naval CIC Officers School, later Training Squadron Eighty-Six (VT-86) - NAS Glynco
      Federal Law Enforcement Training Center
      The Federal Law Enforcement Training Center serves as an interagency law enforcement training organization for 90 United States government federal law enforcement agencies.-Location:...

      , Georgia
      Georgia (U.S. state)
      Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...

  • AEW Wing Pacific - NAS Barbers Point, Hawaii
    • VW-1 ("Typhoon Trackers") - NAS Agana, Guam
      Guam
      Guam is an organized, unincorporated territory of the United States located in the western Pacific Ocean. It is one of five U.S. territories with an established civilian government. Guam is listed as one of 16 Non-Self-Governing Territories by the Special Committee on Decolonization of the United...

    • VW-3 ("Typhoon Chasers") - NAS Agana, Guam
    • VW-12 (BarPac) - NAS Barbers Point, Hawaii
    • VW-14 (BarPac) - NAS Barbers Point, Hawaii
    • VW-16 (BarPac) - NAS Barbers Point, Hawaii
    • AewBarsRon 2 (Service/Support) - NAS Barbers Point, Hawaii
    • MatRon 1 (Support) - NAS Barbers Point, Hawaii
    • AewBarRonPac (amalgamation of VW-12, VW-14, and AEWBarRon 2) - NAS Barbers Point, Hawaii
  • VQ-1 - NAF Atsugi, Japan
  • VQ-2 - NS Rota, Spain
  • VAQ-33 - NAS Norfolk, Virginia / NAS Key West, Florida
  • VXE-6
    VXE-6
    VXE-6, Antarctic Development Squadron 6 , commonly referred to by its nickname, The Puckered Penguins was a United States Navy Air Test and Evaluation Squadron based at McMurdo Station, Antarctica...

     - NAS Quonset Point, Rhode Island

Operational losses

A total of 20 Navy EC-121s were destroyed in accidents, with 113 aircrew deaths:
  • 15 WV-2/EC-121K
  • 3 WV-2Q/EC-121M
  • 2 WV-3/WC-121N


Another EC-121M was destroyed in combat. In 1969, North Korea
North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...

n Air Force MiG fighters shot down an EC-121
EC-121 shootdown incident
The EC-121 shootdown incident occurred on 15 April 1969 when a United States Navy Lockheed EC-121M Warning Star on a reconnaissance mission was shot down by North Korean MiG-17 aircraft over the Sea of Japan...

 off the country's east coast, killing all of the crew of 31 on board.

The USAF had a total of 11 Warning Stars destroyed in accidents, killing 72 aircrew:
  • 2 RC-121C/TC-121C
  • 2 RC-121D
  • 3 EC-121H
  • 3 EC-121R
  • 1 EC-121T


Three EC-121Hs from the 551st AEWCW were lost on 11 July 1965, 11 November 1966 and 25 April 1967, respectively, resulting in 50 deaths, including the wing commander of the 551st AEWCW, Col James P. Lyle. The two Batcat EC-121R crashes resulted in 22 killed.

Survivors

  • EC-121T, AF Serial No. 52-3417 (N4257L) is located at University of Montana at its University of Montana-Helena College of Technology facility in Helena, Montana
    Helena, Montana
    Helena is the capital city of the U.S. state of Montana and the county seat of Lewis and Clark County. The 2010 census put the population at 28,180. The local daily newspaper is the Independent Record. The Helena Brewers minor league baseball and Helena Bighorns minor league hockey team call the...

    . The aircraft is the oldest surviving EC-121, and was delivered to the USAF as a RC-121D in September 1954, and upgraded to an EC-121T in 1970. It served with the Air Force Reserve at Homestead Air Force Base before being retired to Davis-Monthan Air Force Base
    Davis-Monthan Air Force Base
    Davis–Monthan Air Force Base is a United States Air Force base located within the city limits, and approximately south-southeast of downtown, Tucson, Arizona....

     in March 1976. In the early 1980s, the university purchased the aircraft from the Air Force for $10,000 and it was ferried to the university in July 1981. In spring 2009, it was declared surplus by the university and offered to any museum interested in preserving it. The aircraft was eventually acquired by the Evergreen Aviation and Space Museum in McMinnville, Oregon
    McMinnville, Oregon
    McMinnville is the county seat and largest city of Yamhill County, Oregon, United States. According to Oregon Geographic Names, it was named by its founder, William T. Newby , an early immigrant on the Oregon Trail, for his hometown of McMinnville, Tennessee...

    , but it is still in Helena pending completion of restoration for its ferry flight.
  • EC-121T, AF Serial No. 52-3418 (N4257U), c/n 4336, final registration N4257U is on display at the Combat Air Museum
    Combat Air Museum
    The Combat Air Museum is located in Williamsport Township, Shawnee County, near Topeka, Kansas at Forbes Field airport. The Museum rents two hangars from the MTAA. It is one of a handful of major aviation museums in the United States located on an active air field...

     in Topeka, Kansas
    Topeka, Kansas
    Topeka |Kansa]]: Tó Pee Kuh) is the capital city of the U.S. state of Kansas and the county seat of Shawnee County. It is situated along the Kansas River in the central part of Shawnee County, located in northeast Kansas, in the Central United States. As of the 2010 census, the city population was...

    . The aircraft was delivered to USAF in October 1954 as an RC-121D and redesignated an EC-121D in 1962. It was converted to an EC-121T, but the upper radome has been removed.
  • EC-121T, AF Serial No. 52-3425, is on display at the Peterson Air and Space Museum
    Peterson Air and Space Museum
    Peterson Air and Space Museum is located inside Peterson Air Force Base, Colorado Springs, Colorado. Access to the museum is limited due to security concerns, so tour groups should contact the museum curator...

     at Peterson AFB in Colorado Springs, Colorado
    Colorado Springs, Colorado
    Colorado Springs is a Home Rule Municipality that is the county seat and most populous city of El Paso County, Colorado, United States. Colorado Springs is located in South-Central Colorado, in the southern portion of the state. It is situated on Fountain Creek and is located south of the Colorado...

    . Previously assigned to the 966th AEWCS at McCoy AFB, Florida and then the 79th AEWCS at Homestead AFB, Florida, it was the last operational EC-121 and was deployed by the 79th AEWCS to NAS Keflavik, Iceland. It was delivered to Peterson AFB in October 1978.

  • EC-121T, AF Serial No. 53-0548, is owned by Yanks Air Museum
    Yanks Air Museum
    The Yanks Air Museum is a non-profit 501 organization dedicated to exhibiting, preserving and restoring American aircraft and artifacts.-Chino facility and exhibits:...

     in Chino, California
    Chino, California
    Chino is a city in San Bernardino County, California, United States. It is located in the western end of the Riverside-San Bernardino Area and it is easily accessible via the Chino Valley and Pomona freeways....

    . It is presently stored at Camarillo Airport
    Camarillo Airport
    Camarillo Airport is a public airport located three miles west of the central business district of Camarillo, a city in Ventura County, California, United States. It is roughly equidistant from Los Angeles, CA and Santa Barbara, CA although it is inland...

    , although Yanks has been working for several years to get it restored and is in the process of completing FAA paperwork for a ferry flight.
  • EC-121K, AF Serial Number 53-0552 (Navy BuNo 141309), is on display at the Aerospace Museum of California
    Aerospace Museum of California
    The Aerospace Museum of California is an aviation museum located in North Highlands, California on the former McClellan Air Force Base, which closed in 2001. It features displays of authentic military and civilian aircraft as well as space vehicle replicas...

     at the former McClellan AFB, California
    California
    California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

    . This aircraft has seen both USAF and USN service.
  • EC-121T, AF Serial No. 53-0554, is on display at the Pima Air & Space Museum
    Pima Air & Space Museum
    The Pima Air & Space Museum features a display of nearly 300 aircraft spread out over 80 acres on a campus occupying 127 acres . Located in Tucson, Arizona, it is one of the world's largest, non-government funded aerospace museums...

    , adjacent to Davis-Monthan AFB in Tucson, Arizona
    Tucson, Arizona
    Tucson is a city in and the county seat of Pima County, Arizona, United States. The city is located 118 miles southeast of Phoenix and 60 miles north of the U.S.-Mexico border. The 2010 United States Census puts the city's population at 520,116 with a metropolitan area population at 1,020,200...

    .
  • EC-121D, AF Serial No. 53-0555 is on display at the National Museum of the United States Air Force
    National Museum of the United States Air Force
    The National Museum of the United States Air Force is the official museum of the United States Air Force located at Wright-Patterson Air Force Base northeast of Dayton, Ohio. The NMUSAF is the world's largest and oldest military aviation museum with more than 360 aircraft and missiles on display...

     at Wright-Patterson Air Force Base
    Wright-Patterson Air Force Base
    Wright-Patterson Air Force Base is a United States Air Force base in Greene and Montgomery counties in the state of Ohio. It includes both Wright and Patterson Fields, which were originally Wilbur Wright Field and Fairfield Aviation General Supply Depot. Patterson Field is located approximately...

     near Dayton, Ohio
    Dayton, Ohio
    Dayton is the 6th largest city in the U.S. state of Ohio and the county seat of Montgomery County, the fifth most populous county in the state. The population was 141,527 at the 2010 census. The Dayton Metropolitan Statistical Area had a population of 841,502 in the 2010 census...

    . The College Eye EC-121D is fully restored and on display indoors. This aircraft was nicknamed "Triple Nickel" because of its serial number (53-555). On 24 October 1967, while operating over the Gulf of Tonkin
    Gulf of Tonkin
    The Gulf of Tonkin is an arm of the South China Sea, lying off the coast of northeastern Vietnam.-Etymology:The name Tonkin, written "東京" in Hán tự and Đông Kinh in romanised Vietnamese, means "Eastern Capital", and is the former toponym for Hanoi, the capital of Vietnam...

    , it guided a U.S. fighter by radar into position to destroy an enemy fighter aircraft, a MiG-21. This was the first time a weapons controller aboard an airborne radar aircraft had ever directed a successful attack on an enemy aircraft. "Triple Nickel" was retired to the USAF Museum in 1971.

  • EC-121, Navy BuNo 137890, is on display at Tinker Air Force Base
    Tinker Air Force Base
    Tinker Air Force Base is a major U.S. Air Force base, with tenant U.S. Navy and other Department of Defense missions, located in the southeast Oklahoma City, Oklahoma area, directly south of the suburb of Midwest City, Oklahoma.-Overview:...

    , in Oklahoma City, Oklahoma
    Oklahoma City, Oklahoma
    Oklahoma City is the capital and the largest city in the state of Oklahoma. The county seat of Oklahoma County, the city ranks 31st among United States cities in population. The city's population, from the 2010 census, was 579,999, with a metro-area population of 1,252,987 . In 2010, the Oklahoma...

    . The aircraft is on static display outside 552d Air Control Wing
    552d Air Control Wing
    The 552d Air Control Wing is an operational wing of the United States Air Force based at Tinker Air Force Base, Oklahoma. The wing flies the E-3 Sentry aircraft.-History:...

     Headquarters, the home of E-3B/C AWACS operations for the USAF.
  • EC-121K, Navy BuNo 141297, is on display at the Museum of Aviation
    Museum of Aviation
    The Museum of Aviation is the second-largest aerospace museum of the United States Air Force. The museum is located just outside Warner Robins, Georgia, and near Robins Air Force Base. It has a total of five different buildings containing 93 different aircraft on . The SR-71A Blackbird on display...

     at Robins Air Force Base
    Robins Air Force Base
    Robins Air Force Base is a major United States Air Force base located in Houston County, Georgia, United States. The base is located just east of and adjacent to the city of Warner Robins, Georgia, SSE of Macon, Georgia, and about SSE of Atlanta, Georgia...

    , Georgia
    Georgia (U.S. state)
    Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...

    . It was flown to the museum in 1987 for display.
  • EC-121D, Navy BuNo 141311, is on display at the Chanute Aerospace Museum at the former Chanute AFB in Rantoul, Illinois
    Rantoul, Illinois
    Rantoul is a village in Champaign County, Illinois, United States. The population was 13,674 at the 2010 census. The present mayor is Neal Williams, who was re-elected in 2009...

    .
  • EC-121K, Navy BuNo 143221, is on display at the National Museum of Naval Aviation
    National Museum of Naval Aviation
    The National Museum of Naval Aviation is a military and aerospace museum located at Naval Air Station Pensacola, Florida. The museum opened in 1962....

     at Naval Air Station Pensacola
    Naval Air Station Pensacola
    Naval Air Station Pensacola or NAS Pensacola , "The Cradle of Naval Aviation", is a United States Navy base located next to Warrington, Florida, a community southwest of the Pensacola city limits...

     in Pensacola, Florida
    Pensacola, Florida
    Pensacola is the westernmost city in the Florida Panhandle and the county seat of Escambia County, Florida, United States of America. As of the 2000 census, the city had a total population of 56,255 and as of 2009, the estimated population was 53,752...

    . The aircraft was acquired in flyable condition in 1973 from Training Squadron 86 (VT-86) at NAS Glynco, Georgia
    Georgia (U.S. state)
    Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...

    . It is on display at the Sherman Field flight line annex of the museum.
  • EC-121T (N6937C) is on display at the Airline History Museum
    Airline History Museum
    The National Airline History Museum is located at the Kansas City Downtown Airport in Kansas City, Missouri, USA.- History :Founded in 1986 by aviation enthusiasts Larry A. Brown and Dick McMahon, the Airline History Museum was originally known as Save-A-Connie...

     in Kansas City, Missouri
    Kansas City, Missouri
    Kansas City, Missouri is the largest city in the U.S. state of Missouri and is the anchor city of the Kansas City Metropolitan Area, the second largest metropolitan area in Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties...

    .

Specifications (WV-2/EC-121D)

See also

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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