Lajes Field or Lajes Air Base (; ), officially designated Air Base No. 4 (Base Aérea n.º 4, BA4) , is a multi-use airfield near Lajes and northeast of Angra do Heroísmo on Terceira Island in the Azores, Portugal. Located about east of New York City and about west of Lisbon, Portugal, the base sits in a strategic location midway between North America and Europe in the north Atlantic Ocean.

It is home to the Portuguese Air Force Base Aérea n.º 4 and Azores Air Zone Command (), a United States Air Force detachment unit (operated by the 65th Air Base Group of United States Air Forces in Europe - Air Forces Africa), and a regional air passenger terminal.

History The origin of the Lajes Field dates back to 1928, when Portuguese Army Lieutenant Colonel Eduardo Gomes da Silva wrote a report on the possible construction of an airfield in the plainland of Lajes, for that branch's aviation service (). The location of Achada on the center of Terceira Island was chosen instead. In 1934, the Achada airfield was condemned due to its inadequate dimensions and adverse weather conditions, resulting in the construction of a landing strip of packed earth and a small group of support facilities by the Portuguese military at Lajes.

World War II

During World War II, in order to defend Portuguese neutrality and deter both Nazi Germany and the Allies against a possible invasion of the Azores, the Portuguese Government significantly increased the garrisons of the isles, by mobilizing local forces and by sending about 28,000 troops and equipment from Mainland Portugal. As part of the defenses of Terceira Island, Lajes Field received a squadron of Gloster Gladiator fighters, having its runway expanded and becoming officially the Air Base No. 4.

In 1942, the military activities in the Azores grew, as the Gladiators began to be used to support allied convoys, in reconnaissance missions and on meteorological flights. A number of Junkers Ju 52, of the Portuguese Bomber Squadron sent to the Azores in 1941, deployed to Lajes in July 1942, to fly cargo missions.

The Portuguese Government kept a collaborating neutrality towards the Allies and by 1943, the British and American armed forces were allowed basing rights in Portugal. Within a month of disembarking on Terceira in October 1943, the Royal Air Force (RAF) had laid pierced steel planking to lengthen the runway at Lajes Field, allowing the RAF to begin patrols. The first attack on a German U-boat was conducted in November, sinking the submarine; this attack was followed by a dozen more attacks on U-boats by the end of February 1944, after which German forces stayed clear of the British and American patrol areas. The Azores enabled British and American airmen to protect Allied shipping in the area.

On 1 December 1943, British and U.S. military representatives at RAF Lajes Field signed a joint agreement outlining the roles and responsibilities for the United States Army Air Forces (USAAF) and United States Navy (USN) at Lajes Field. The agreement established guidelines and limitations for the ferrying of aircraft to Europe via Lajes Field. In return, the US agreed to assist the British in improving and extending existing facilities at Lajes. Air Transport Command transport planes began landing at Lajes Field immediately after the agreement was signed. By the end of June 1944, more than 1,900 American airplanes had passed through the base. Using Lajes, the flying time relative to the usual transatlantic route between Brazil and West Africa was nearly cut in half from 70 to 40 hours.

Lajes Field was one of the two stopover and refueling bases for the first transatlantic crossing of non-rigid airships (blimps) in 1944. The USN sent six Goodyear-built K-ships from Naval Air Station South Weymouth in Massachusetts to their first stopover base at Naval Station Argentia, Newfoundland and then on to Lajes Field in the Azores before flying to their final destination at Port Lyautey (Kenitra), French Morocco.

From their base with Fleet Air Wing 15 at Port Lyautey, the blimps of USN Blimp Squadron 14 (ZP-14 or Blimpron 14) conducted night-time anti-submarine warfare (ASW) to search for German U-boats around the Strait of Gibraltar using magnetic anomaly detection (MAD). In 1945, two ZP-14 replacement blimps were sent from Weeksville, North Carolina, to the Bermudas and Lajes before going on to Craw Field (Kenitra Air Base) at Port Lyautey.

Post-war

The United States and the United Kingdom transferred control of Lajes back to Portugal in 1946. The Portuguese redesignated Lajes as Air Base No. 4 and assigned it to the air branch of the Portuguese Army. However, talks between the U.S. and Portugal began about extending the American stay in the Azores. A temporary agreement was reached between the U.S. and Portuguese governments giving the U.S. military rights to Lajes Field for an additional 18 months: the relationship between the Portuguese and American governments continues to this day, where the U.S. military resides under a tenancy status, and the Portuguese government retaining rights of ownership to the land and infrastructure. Lajes Field remains Portuguese Air Base 4 under the direction of Headquarters Azores Air Zone commanded by Portuguese Air Force brigadeiro (equal to a U.S. two-star general).

In 1947, the Portuguese Search and Rescue Squadron 41 (Esquadra 41) started to operate from Lajes, equipped with Boeing SB-17, Grumman HU-16 Albatross, Douglas C-54 Skymaster and, later Sikorsky H-19 helicopters. In 1952, the U.S. Air Force activated the 57th Air Rescue Squadron at Lajes Field, where it was based until inactivated in 1972. These units were responsible for the search and rescue (SAR) operations in the Atlantic between Europe and North America.Mais Alto 348, p. 37

In 1949, the North Atlantic Treaty Organization (NATO) military alliance was established. Portugal, the United States, the United Kingdom, Canada, and other western European countries were charter members of NATO. By reason of the NATO alliance, Lajes was available for use by those countries, and the use of Lajes was one of Portugal's primary contributions to the alliance. However, use of Lajes Field by the U.S. Department of Defense takes place under a U.S.-Portuguese Status of Forces Agreement (SOFA), separate and in addition to NATO arrangements.

In 1953, Admiral Lynde D. McCormick, the Commander-in-Chief, United States Atlantic Command organized a subordinate unified command in the Azores called U.S. Forces Azores (USFORAZ). A small staff of United States Army, United States Air Force, and United States Marine Corps personnel composed the joint staff of USFORAZ, serving as the liaison between the U.S. and the Portuguese in the Azores.

In the late 1950s, USAF air refueling/tanker aircraft were stationed at Lajes to provide inflight refueling for U.S. aircraft transiting the Atlantic Ocean. Some of the tanker units left Lajes by 1965, but others returned later, especially the USAF Boeing KC-135 Stratotanker. This transfer, coupled with the introduction of newer long-range aircraft, resulted in a gradual decline in Lajes traffic. The Military Air Transport Service (MATS) and its successor, the Military Airlift Command (MAC), became responsible for USAF activities at the base, and for a while the 1605th Military Airlift Support Wing acted as USAF host unit.

Lajes Field also played a crucial role in Cold War politics. From 1932 to 1968, Portugal was under the authoritarian regime of António de Oliveira Salazar, yet the U.S. Government maintained friendly relations with his Estado Novo government, especially after 1943. The Cold War military importance of Lajes Field outweighed considerations about the Salazar Government's authoritarian rule over Portugal.

In 1961, the Portuguese Air Force Heavy Aircraft Advanced Training Squadron 42 (Esquadra 42 - EICAP) was transferred to Lajes, operating Douglas C-47, Douglas C-54 and later CASA C-212 Aviocar.

During the Portuguese Overseas War, from 1961 to 1975, the Air Force Hospital at Lajes operated as the main centre for treatment and rehabilitation of mutilated and heavy burned soldiers of the three services of the Portuguese Armed Forces.CANN, John P., Counterinsurgency in Africa: The Portuguese Way of War, 161-1974, Westport, CT, USA: Greenwood Publishing Group, Inc., 1997

In December, 13th and 14th, 1971, Lajes Field hosts the Atlantic Summit between U.S. President Richard Nixon, French President Georges Pompidou and Portuguese prime-minister Marcelo Caetano.

During the 1973 Yom Kippur War, Lajes Field also supported Operation Nickel Grass, the U.S. airlift missions to Israel, highlighting the importance of the U.S. Air Force base at Lajes.

Another important Cold War operation at Lajes was the U.S. Navy's Naval Air Facility Lajes (NAF Lajes), a tenant activity at the air base. NAF Lajes, and its associated Tactical Support Center (TSC)/Antisubmarine Warfare Operations Center (ASWOC), supported rotational detachments of U.S. Navy P-2 Neptune and later P-3 Orion maritime patrol aircraft that would track Soviet attack, guided missile, and ballistic missile submarines in the region. With the collapse of the Soviet Union and the Warsaw Pact, and end of the Cold War, P-3 operations at Lajes declined, and the Naval Air Facility was inactivated in the late 1990s.

Post-Carnation Revolution

Following the Portuguese Air Force reorganization of 1978, Lajes Air Base comes to have two resident flying units: Transport Squadron 503 (Esquadra 503) - equipped with CASA C-212 aircraft and Helicopter Search and Rescue Squadron 752 (Esquadra 752) - equipped with Aérospatiale SA 330 Puma helicopters. In 1980, a detachment of Attack Squadron 301 (Esquadra 301) - equipped with Fiat G.91 fighter-bombers - starts to be based at Lajes, this being augmented and becoming the Attack Squadron 303 "Jaguars" (Esquadra 302, "Jaguares") in 1981.

The Azores Islands earthquake affected Terceira Island. Damage to Lajes Field was minimal, but Portuguese communities throughout the island suffered extensive damage. Military personnel responded with food, shelter, equipment, and manpower.

In the summer of 1984, Lajes undertook a new mission known as "SILK PURSE." Boeing EC-135s began operating out of Lajes Field as an airborne command post for the U.S. Commander-in-Chief, Europe. Along with the aircraft came the U.S. European Command battle staff and flight crews from United States Air Forces in Europe. This mission was ended in late August 1991.

In 1990, Squadron 303 was disbanded.

Lajes supported the large airlift during the Gulf War. On the first day of the deployment over 90 aircraft transited Lajes. Strategic Air Command (SAC) created a provisional tanker wing, the 802nd Air Refueling Wing (P) Provisional, at Lajes to support the airlift. At the height of the operation a peak of 33 tanker aircraft and 600 troops deployed to Lajes. Soon after the Gulf War ended, Lajes command changed from Air Mobility Command, to Air Combat Command.

In 1993, squadrons 503 and 752 are merged in a single mixed unit operating both C-212 and Aérospatiale Puma, the 711 Squadron Albatrosses (Esquadra 711 "Albatrozes").

The resident Portuguese 711 Squadron was deactivated on 30 November 2006. With this act the long-serving Aerospatiale Puma was retired from service.The deactivation resulted in the storage of one unit at Lajes, one at the Museum at Sintra and the remaining eight helicopters placed in storage at Air Base No. 11 in Beja The Puma helicopters were replaced by the modern AgustaWestland AW101 Merlin: the Portuguese government purchased twelve units for SAR, CSAR and Fisheries enforcement. Air Base No. 4 received three Merlins on permanent detachment from Esquadra 751 "Pumas" from Air Base No. 6 at Montijo, near Lisbon. They saw immediate service starting 1 December 2006.