Portuguese naval aviation began on 28 September 1917 with a seaplane station at Bom Sucesso in the Lisbon docks. By the Second World War the dock was too small, and the Navy began building a larger station on the Montijo peninsula, on the south bank of the Tagus, where there was room for both a seaplane slipway and a land airfield. The Air Force page puts the base at about 1,000 hectares of flat ground.

The station was named after Comandante Sacadura Cabral, the naval aviator who flew the first aerial crossing of the South Atlantic in 1922. Its motto, “Onde a Terra Acaba e o Mar Começa” (where the land ends and the sea begins), echoes a line of Camões. A small detachment under Capitão-Tenente Tello Pacheco moved in early in 1952, and local press and the Portuguese Wikipedia date the formal inauguration as the Centro de Aviação Naval to 2 January 1953.

The timing was awkward. The Portuguese Air Force had been created in 1952 by merging army and naval aviation, and the new station was handed over almost at once: Portaria 14.281 of 3 March 1953 renamed it Base Aérea N.º 6. Sources disagree on when the naval units were fully absorbed. Montijo On City gives 12 July 1954, the Portuguese Wikipedia 12 June 1954, and the English Wikipedia says integration was complete only in late 1956 or early 1957. What is not in doubt is that naval aviation as a separate arm had disappeared by 1958.

For its first three decades Montijo was Portugal’s anti-submarine base. The Air Force lists the types that flew from it before 1953 as Fleet trainers, Grumman amphibians, Curtiss Helldivers and Harvards. After the merger came Lockheed PV-2 Harpoons, from 1956 according to the Portuguese Wikipedia, and then P2V-5 Neptunes, which gave Portugal a real long-range patrol capability over the Atlantic approaches to Portugal, a NATO member since 1949.

The base was never a single-role station. The Air Force’s list of past aircraft also includes Douglas DC-6 transports, Alouette III and Puma helicopters, Fiat G.91 jets and CASA C-212 Aviocars. The Alouettes of Esquadra 551 served here from 1978 until the squadron was merged into Esquadra 552 on 30 September 1986, and the first VIP jets, three ex-Federal Express Falcon 20s of Esquadra 504 “Linces”, were based here from 12 January 1985 until they moved to Figo Maduro in 1990.

The last great maritime type at Montijo was the Lockheed P-3P Orion. Esquadra 601 “Lobos” was formed in March 1986 and its first P-3P landed at Montijo on 7 August 1988. For twenty years the Orions flew patrols over the vast Portuguese ocean zone from here, until the squadron moved to Beja on 19 February 2008, where it now flies ex-Dutch P-3C CUP+ aircraft. The move left Montijo as the Air Force’s transport and rescue base.

Esquadra 501 “Bisontes” traces its air transport roots to Exercise Himba in 1959, which tested the Air Force’s ability to fly troops to the overseas territories, and to the Skymasters, Dakotas, DC-6s and Boeing 707s that followed. The squadron took delivery of its first C-130H in 1977. The Air Force says the Hercules fleet has since logged nearly 70,000 flying hours, with missions to Angola, Mozambique, São Tomé, Cape Verde, Timor, the Gulf, Afghanistan, Rwanda, the Balkans, Haiti, Egypt and Libya.

The Hercules is Portugal’s tool for getting its citizens out of trouble. In June 2025, when Israeli airspace closed after the strikes on Iran, C-130H 16806 left Montijo on 16 June with a crew of six, flew via Cyprus to Sharm el-Sheikh and brought out 120 people, most of them Portuguese, who had travelled 570 km by road from Tel Aviv. It was back at Montijo on 19 June.

The fleet is old but not finished. OGMA at Alverca modernised four C-130Hs with structural work and new navigation and communication avionics, and delivered the last one to Montijo in late 2025, according to NewsAvia. The Air Force service data list three to four airframes, a figure that varies with maintenance. The five Embraer KC-390s of Esquadra 506 at Beja now carry much of the strategic airlift, and the Hercules is expected to hand over to them over time.

Esquadra 751 was created on 28 April 1978 (the English Wikipedia gives 29 April) with SA-330 Pumas, which gave the squadron its name. The Air Force says it has saved more than 5,000 lives in about 64,000 flying hours. Early work was close to home: in the Tagus floods of 1979 and 1983, according to a civil protection study cited by the Portuguese Wikipedia, its helicopters flew 163 missions and evacuated 1,386 people. The squadron motto is “Para que outros vivam”, so that others may live.

The Pumas were replaced by twelve AgustaWestland EH-101 Merlins delivered from 2005, operational at Montijo from February 2006. MILAVIA, visiting in 2022, recorded six Mk514 rescue aircraft, four Mk516 combat search and rescue aircraft and two Mk515 fisheries-protection aircraft. The Merlin roughly doubled the rescue radius, from 200 to 400 nautical miles, which matters over a search and rescue region of about 5 million square kilometres, largely the Lisbon and Santa Maria flight information regions.

Montijo keeps one Merlin and one crew on permanent alert, Porto Santo in Madeira another, and Lajes in the Azores two aircraft because its workload is heavier. A standard crew is five: two pilots, a winch operator, a rescue swimmer and a flight nurse. In 2022 the squadron said it typically saved 180 to 200 people a year and flew a real rescue about every three days. Its captain was candid that the Merlin is expensive to maintain, and that roughly half the fleet is in maintenance at any time.

Montijo’s long runways, flat ground and position opposite Lisbon made it the obvious candidate for a second airport. On 8 January 2019 the state and ANA Aeroportos de Portugal signed an agreement worth 1.15 billion euros to 2028 to expand Humberto Delgado airport and turn the air base into a civil airport for Lisbon. The Air Force squadrons would have had to move; the Portuguese Wikipedia reports plans to send the transport squadrons to Tancos and the Merlins to Sintra.

The Tagus estuary is a major feeding ground for wintering birds. On 30 October 2019 the environment agency APA gave a conditionally favourable opinion, with about 48 million euros of compensation for some 2,500 hectares of feeding and nesting habitat and for noise insulation, and the formal environmental declaration followed on 21 January 2020. Eight environmental groups, backed by ClientEarth, went to the Lisbon Administrative Court in 2020 to have it annulled.

Then the councils decided the matter. The law required every affected municipality to agree. Barreiro and Montijo said yes, Seixal and Moita said no, and Alcochete gave no opinion, so on 2 March 2021 the regulator ANAC refused even to assess the project. In January 2024 APA declined to renew the environmental declaration after ICNF cited research that the airport could cost up to 30% of the estuary’s value for wintering birds. On 14 May 2024 the government chose Alcochete instead, and in April 2026 the Lisbon court declared the Montijo process lapsed.

Losing the airport contest has given the base a bigger future, not a smaller one. On 10 July 2025 the Council of Ministers authorised the Air Force to spend up to 30 million euros moving Aeródromo de Trânsito N.º 1, the Figo Maduro military terminal inside Lisbon airport, to Montijo by the end of 2028. The aim is to give Humberto Delgado more room for airliners until the new Luís de Camões airport opens on the Air Force’s own Alcochete firing range, which must itself move.

Today the base is home to three Air Force flying squadrons. Esquadra 502 “Elefantes”, formed at Tancos in 1955, arrived in 2009 with the C-295M; twelve were delivered between 2006 and 2011, seven transports and five maritime surveillance aircraft, with detachments in Madeira and the Azores. Alongside Esquadra 501 and Esquadra 751 sit the Air Force Survival Training Centre (CTSFA), which trains aircrew in land and sea survival and evasion, and the Navy’s helicopter flight.

That Navy flight was created in 1993 for the Vasco da Gama-class frigates, and its first two Super Lynx Mk95s arrived at Montijo on 29 July 1993. The Air Force unit page dates the flight to 1992, the Navy to 8 June 1993. Its Lynx detachments sailed for the Sharp Guard embargo off the former Yugoslavia, the 1998 evacuations from Guinea-Bissau, East Timor and the Atalanta and Ocean Shield counter-piracy operations, returning each time to an air force base that has been sharing its apron with sailors since the day it opened.