London-Heathrow Airport: Aviation's Big Ben! Airport Analysis #11
Exploring the History, Operations, and Terminals of Europe's Busiest Aviation Hub
Welcome back, dearest travelers! We would be severely remiss if we did not cover London-Heathrow Airport in our aviation analysis series. Not only is it an immensely popular and busy airport, but it is also a crucial nexus and hub in global aviation. It is the largest airport serving London and southern England (really, all of the United Kingdom), but it is the largest of the six international airports in the London airport system (the others being Gatwick, Stansted, Luton, City, and Southend). It is also, ironically, the only airport within the city limits of London.
In 2025, Heathrow was the busiest airport in Europe, the fifth-busiest airport in the world by passenger traffic, and the second-busiest airport in the world by international passenger traffic. In 2024, Heathrow had the most connections of any international airport in the world.
Heathrow was founded as a small airfield in 1930 but was developed into a much larger airport after World War II. It lies 14 miles west of Central London on a site that covers 4.74 square miles. It was gradually expanded over 75 years and now has two parallel east–west runways, four operational passenger terminals, and one cargo terminal. The airport is the primary hub for British Airways and Virgin Atlantic.
The airport was opened on 25 March 1946 as London Airport; it was renamed Heathrow Airport in the last week of September 1966 to avoid confusion with the other two main airports serving London: Gatwick and Stansted.
In 1915, Fairey Aviation, founded by British aero-engineer and plane builder Charles Richard Fairey, started assembling and flight-testing its aircraft from Northolt Aerodrome, about six miles north of the modern Heathrow Airport. World War II aficionados might recognize Fairey as the manufacturer of the Fairey Swordfish biplane, which helped find and sink the Kriegsmarine battleship Bismarck.
Skipping ahead a bit in the airport’s foundational history to June 1930, the airfield at Heathrow was declared operational. From about 1937 to 1939, the airfield was first called Harmondsworth Aerodrome, then the Great West Aerodrome, and sometimes Heathrow Aerodrome. One prewar map simply labeled it "Airport." A primitive hangar was built next to a dirt runway. Fairey planned to relocate its factory to the site. The Great West Aerodrome was used for aircraft assembly and testing.
What became the airport was used by the RAF during the Second World War, but only for diversions.
During the Battle of Britain in 1940, Hawker Hurricane fighters of No. 229 Squadron from RAF Northolt were sent to the Great West Aerodrome (Heathrow) when there was a threat of enemy attack on Northolt. During the middle of the war in 1942, Richard Fairey was knighted as Sir Richard Fairey and held the position of Director General of the British Air Mission, based primarily in Washington, D.C. A year later, in 1943, Fairey Aviation bought 10 more acres (4.0 ha) of land to add to the total of 230 acres (93 ha) bought in 1929, 1930, and 1939, respectively, in segments.
The airport finally coalesced in 1943. The Air Ministry, headed by the Secretary of State for Air, Sir Archibald Sinclair, secretly developed plans to requisition the airfield under wartime legislation—the Defence of the Realm Act 1914. The plans were stated to be designed to suit the considerable needs of long-range bombers, such as the Boeing B-29s of the United States Army Air Forces (USAAF), but they were actually based on recommendations from Professor Patrick Abercrombie for a new international airport for London. The project was headed by Harold Balfour (then Under-Secretary of State for Air, later Lord Balfour of Inchrye), who kept the true nature of it hidden from Parliament. The decision and plans were finally revealed to the public a year later, while the war still raged. The wartime legislation provided no obligation to pay compensation for the development, headed by none other than Fairey Aviation, which was told it had to pay for the airport development out of its own pocket.
In February 1944, Prime Minister Winston Churchill objected to the usage of 3,000 men and much effort on the Heathrow Airport project during the run-up to Operation Overlord (in June of that year, also known as the Normandy Invasion). The Ministry of Agriculture and Fisheries objected to the loss of good farm and market garden land on the airport's grounds.
This is where the airport's history gets really interesting. Then, in February, the Air Ministry requisitioned the airfield and surrounding farms, roads, and houses, ostensibly to accommodate military bombers. Harold Balfour (later Lord Balfour), then Under-Secretary of State for Air (1938–44), wrote in his 1973 autobiography, Wings over Westminster, that he deliberately deceived the government committee into believing a requisition was necessary so that Heathrow could be used as a base for long-range transport aircraft in support of the war with Japan. In reality, Balfour wrote that he always intended the site to be used for civil aviation and used a wartime emergency requisition order to avoid a lengthy and costly public inquiry. This took over all or part of twenty farmers' and market gardeners' landholdings, in total about 1,300 acres (530 ha) initially. Construction of the new airport finally began. The modern Heathrow, in essence, began as a result of deception.
In January 1946, ownership of the site was transferred from the (military) Air Ministry to the Ministry of Civil Aviation. An inaugural flight on Runway 1 had recently been completed; Runways 2 and 3 were finally approaching completion. The airport buildings, however, were army marquees and caravans and prefabricated RAF huts. Hardly suitable for civilian use.
In March of that year, Reginald Fletcher, 1st Baron Winster, the Minister of Aviation, performed the official opening ceremony, such as it was. The first aircraft to use the new airport was a British South American Airways (BSAA) Avro Lancastrian named Star Light, captained by BSAA's managing director, Sir D. T. Bennett.
The passenger terminal was an area of army tents and duckboarding (a slightly elevated wood-plank causeway) next to the south side of the airport's access road, Bath Road. Later, the tents were replaced by prefabricated buildings. (It was opposite the Bricklayers Arms pub, which in 1954 was renamed the Air Hostess and in 1988 was completely demolished.) The first control tower was an extremely crude brick building (three stories, plus two huts on its flat roof) roughly where the airport police station was later built.
In May, the airport was fully opened for civilian use. The first passenger to use the airport was the war hero and multiple medal recipient Charles Upham.
Three more runways completed the hexagram of the airport in 1952–1954; two runways would always be within 30° of the wind's variable direction(s), regardless of which direction a plane landed.
In February 1952, Princess Elizabeth returned to the United Kingdom, stepping onto British soil as Her Majesty Queen Elizabeth II following the death of her father, His Majesty King George VI. She arrived on the BOAC (British Overseas Airways Corporation) Argonaut Atlanta (a four-engine propeller aircraft) in an area of the airport now covered by the Brasserie Restaurant of the prestigious Heathrow Renaissance Hotel.
By 1955, Queen Elizabeth II opened the first permanent passenger terminal, the Europa Building (later known simply as Terminal 2), as well as the adjacent and equally large Queens Building. These terminal buildings stood in the central area in the middle of the star pattern of runways and were reached by a twin access tunnel from Bath Road (A4), passing under Runway 10L/28R.
In the 1960s, more advancements continued, starting in 1961. Building 3, the Oceanic Building (renamed Terminal 3 in 1968), specifically opened to handle long-haul flight departures.
In April 1969, Her Majesty Queen Elizabeth II formally inaugurated Terminal 1. The original terminals being in the centre of the site became a constraint on expansion. Built for easy access to all runways, it was assumed that passengers using the terminals would not need extensive car parking, as air travel was beyond all but the wealthy, who would be chauffeur-driven, with chauffeurs leaving with their cars once passengers had departed or coming back later to collect returning passengers.
The 1970s saw continued expansion and additions to the airport. The cargo terminal was added during this decade. In 1974, the Royal Army occupied Heathrow, ostensibly for training against alleged terrorist action by the Provisional Irish Republican Army, or PIRA. Mass transit to downtown London was also added as Heathrow grew in popularity.
In the 1980s, annual passenger numbers had increased to 30 million passengers per annum and required more terminal space. Terminal 4 was built south of the southern runway, on the site of newly bought-out farms and farmland called Mayfield Farms, next to the existing cargo terminal and away from the three older terminals, with connections to Terminals 1, 2, and 3 by the existing Heathrow Cargo Tunnel. The cargo border road is still called Mayfield Farm Road. The London Underground was finally connected in 1984, creating a one-way, nonstop airport transit route called the Piccadilly Line. In 1986, Terminal 4 was opened by Prince Charles (now King Charles) and Diana, Princess of Wales, and immediately became the home base and hub of the newly privatized British Airways.
In 1987, the UK government privatized the British Airports Authority (BAA), which controlled Heathrow and six other London-area airports. They were now elements of a Crown corporation.
Following privatization, during the late 1980s and 1990s, BAA expanded the proportion of terminal space allocated to retail activities and invested in retail development. This included expanding terminal areas to provide more shops and restaurants and routing passengers through shopping areas to maximise their exposure to retail offerings.
In the 1990s, expansion was replaced by chaos. In 1994, the Heathrow mortar attacks were carried out by the Provisional Irish Republican Army (PIRA).
A pleasant first occurred on 7 February 1996: Concorde, registry G-BOAD, arrived at Heathrow after crossing the Atlantic Ocean from New York City (JFK) in a new record time of 2 hours, 52 minutes, and 59 seconds from gate to gate.
In 1997, the planning stage of the Terminal 5 Public Planning Inquiry ended at a total cost of £80 million pounds sterling. Testimony was heard from 700 witnesses, and 100,000 pages of transcripts were recorded. The consultation process for T5 took 524 days; eight years elapsed from the first application to final government approval—the longest-ever planning process in UK history. A year later, the Heathrow Express began providing a non-underground modern railway service originating from Paddington Station in London.
Entering the new millennium, it was fairly quiet for Heathrow, though expansion once again continued. In 2002, construction of Terminal 5 finally began. Its first stage (which took 18 months) was the Twin Rivers Diversion Scheme, diverting the Longford River and the Duke of Northumberland's River around the western perimeter of the airport and realigning the two perimeter roads to fit Terminal 5 properly.
The Eastern Extension of Terminal 1 opened in 2004, becoming fully active and open to passengers in early 2005.
From 7 January 2005 to 17 September 2006, the underground railway loop via Heathrow Terminal 4 was closed to connect a spur line to Heathrow Terminal 5 station. Heathrow Terminals 1, 2, and 3 was again a terminus. Shuttle buses served Terminal 4 from Hatton Cross bus station.
In 2008, Queen Elizabeth II opened Terminal 5. On 18 March 2008, following delays in the A380's production, the first A380 in scheduled passenger service, Singapore Airlines Flight 380 (fittingly), with registration number 9V-SKA, touched down from Singapore carrying 470 passengers, marking the first-ever European commercial flight by the A380. A third event in 2008 was the opening of Terminal 5 to passengers. Heathrow Terminal 5 station also opened.
To cap off 2008, Terminal 2B started being constructed. A year later, in 2009, the Queen's Building was demolished. By the beginning of 2009, a new third runway and sixth terminal were controversially approved by UK government ministers. By October, British Airways had vacated Terminal 4 and moved to Terminal 5. In November, the first stage of building Terminal 2B was completed, and at the end of the month, the old Terminal 2 closed.
Moving into the 2020s and the COVID era, the airport conducted "routine" business—in other words, expansion and rebuilding. The COVID-19 pandemic damaged the global aviation and tourism industry significantly; the airport announced that from 6 April, the airport would switch to single-runway operation. It was reported that some 200 homeless people had moved to using Heathrow Airport, as some of the London amenities they were used to using were closed due to the UK lockdown. In March 2025, a fire at the North Hyde electrical substation, which started at approximately 23:23 GMT (Greenwich Mean Time) the previous night, promptly caused all flights to be cancelled and the airport to be closed on 21 March. More than 1,300 flights were affected over a 24-hour period. Arriving flights had to be diverted to nearby airports such as Luton and Gatwick and even London City Airport.
Now that we have finished a snapshot of the history of Heathrow Airport, let’s take a quick look at the operations. Heathrow Airport is used by over 89 airlines flying to 214 destinations in 84 countries. The airport is the primary hub for both British Airways and rival Virgin Atlantic. It has four passenger terminals (numbered 2 to 5) and a cargo terminal. Heathrow Airport has four terminals with a total of 115 gates, 66 of which can support wide-body aircraft and 24 gates that can support an Airbus A380. In 2021, Heathrow served a mean, or average, of 19.4 million passengers, of which 17 million were international and 2.4 million domestic—passengers originating or ending their trip at Heathrow. The busiest year ever recorded in modern aviation history was 2024, when 83.9 million passengers travelled through the airport.
Aircraft destined for Heathrow are usually routed to one of four holding points. Air traffic controllers at Heathrow Approach Control (based in Swanwick, Hampshire) then guide the aircraft to their final approach, merging aircraft from the four holds into a single stream of traffic, sometimes as close as 2.5 nautical miles (4.6 km; 2.9 mi) apart. Once an aircraft is established on its final approach, control is handed over to Heathrow Tower at Heathrow itself.
North of the northern runway and the former taxiway and aprons, now the site of extensive car parks, is the entrance to the airport access tunnel and the site of Heathrow's unofficial "gate guardian," which stands as a gargoyle, welcoming travelers to the airport. For many years, this site was the home of a 40% scale model of a British Airways Concorde. The Concorde has been officially replaced by an Emirates Airlines Airbus A380 model since 2008.
There is a multi-faith prayer room and counselling room in each terminal. Heathrow Airport has Anglican, Catholic, Free Church, Hindu, Jewish, Muslim, and Sikh chaplains on-site and on-call, including individual prayer rooms. These chaplains are based in St. George's Interdenominational Chapel in an underground vault adjacent to the old control tower, where Christian services take place (other faiths have services above ground). The chaplains organize and lead prayers at certain times in the prayer room for all listed faiths.
Night-time flights at Heathrow are subject to significant restrictions. Between 23:00 and 04:00, the noisiest aircraft cannot be scheduled for operation, which airlines find incredibly annoying.
Policing of the airport is the responsibility of the Aviation Policing Command, a unit of the London Metropolitan Police, although the British Army, including armored vehicles of the Household Cavalry (members of the royal household), has occasionally been deployed at the airport during periods of heightened security. Full-body scanners are now used at the airport, and passengers who refuse to use them are required to submit to a hand search in a private room, identical to airports in the United States.
In terms of cargo, the top cargo export destinations include the United States, China, and the United Arab Emirates, with Heathrow handling 1.6 million tons of cargo in 2024. The top products exported were books, salmon, and medicine.
We’ll go over Heathrow’s terminals quickly to wrap up this article.
Terminal 2 (T2)
There is no Terminal 1. Also, the airport's newest terminal, officially known as the Queen's Terminal, was opened on 4 June 2014 and has 24 gates. It was built on the site that had been occupied by the original Terminal 2 and the Queens Building. Terminal 2 underwent six months of testing before opening to passengers. It includes a satellite pier (T2B), a 1,340-space car park, and a cooling station to generate chilled water. There are 52 shops, 17 bars, and restaurants.
The airlines moved from their original locations over six months, with only 10% of flights operating from there in the first six weeks (United Airlines' transatlantic flights). On 4 June 2014, United became the first airline to move into Terminal 2 from Terminals 1 and 4, followed by All Nippon Airways, Air Canada, and Air China from Terminal 3. Air New Zealand, Asiana Airlines, Croatia Airlines, LOT Polish Airlines, South African Airways, and TAP Air Portugal moved in on 22 October 2014. Flights using Terminal 2 primarily originate from northern Europe or western Europe. It is primarily used by Star Alliance airlines (which consolidate under Star Alliance's co-location policy, "Move Under One Roof"). The terminal is also used by a few non-aligned airlines. Terminal 2 is one of the two terminals that operate both UK domestic and Irish flights.
Terminal 3 (T3)
Terminal 3 opened as the Oceanic Terminal on 13 November 1961 to handle departures for long-haul routes to the United States and Asia for foreign carriers. At this time, the airport had a direct helicopter service to central London from the gardens on the roof of the terminal building. Renamed Terminal 3 in 1968, it was expanded in 1970 with the addition of an arrivals building. Other facilities added included the UK's first moving walkways. In 2006, the new £105 million Pier 6 was completed to accommodate the Airbus A380 superjumbo; Emirates and Qantas operate regular flights from Terminal 3 using the Airbus A380.
Redevelopment of Terminal 3's forecourt, including a new four-lane automobile drop-off area and a large pedestrianised plaza, complete with a canopy at the front of the terminal building, was completed in 2007. These improvements were intended to improve passengers' experience, reduce traffic congestion, and improve security. As part of this project, Virgin Atlantic was assigned its own dedicated check-in area, known as 'Zone A,' which features a large sculpture and atrium.
Terminal 3 has an area of 98,962 m2 (1,065,220 sq ft) with 28 gates, and in 2023, it handled 19.2 million passengers on 104,100 flights.
Most flights from Terminal 3 are long-haul flights to America, Asia, and other foreign countries. Terminal 3 is home to Oneworld members (with the exception of Malaysia Airlines, Oman Air, Qatar Airways, and Royal Air Maroc, all of which use Terminal 4), SkyTeam members Aeroméxico, China Airlines, Delta Air Lines, Middle East Airlines, Virgin Atlantic, and several long-haul unaffiliated carriers. British Airways also operates several flights from this terminal, as do Iberia and Iberia’s low-cost cousin, Vueling.
Terminal 4 (T4)
Opened in 1986, Terminal 4 has 22 gates. It is situated to the south of the southern runway next to the cargo terminal and is connected to Terminals 2 and 3 by the Heathrow Cargo Tunnel. The terminal has an area of 1,135,390 sq ft and is now home to the SkyTeam alliance, except Scandinavian Airlines, which uses Terminal 2, and China Airlines, Aeroméxico, Delta Air Lines, Middle East Airlines, and Virgin Atlantic, which use Terminal 3. This terminal is also the base for several Oneworld carriers, such as Malaysia Airlines, Qatar Airways, and Royal Air Maroc, besides a few unaffiliated carriers, such as Etihad Airways, Gulf Air, Royal Brunei Airlines, and WestJet. It has undergone a £200 million upgrade to accommodate 45 airlines, with an upgraded forecourt to reduce traffic congestion and improve security. Most flights using Terminal 4 are those from/to Eastern Europe, Central Asia, North Africa, and the Middle East, as well as a few flights from/to Europe. An extended check-in area with renovated piers and departure lounges and a new baggage system were installed, and four new stands were built to accommodate the Airbus A380; Qatar Airways operates regular A380 flights.
Terminal 5 (T5)
Lastly, we have Terminal 5. Terminal 5 lies between the northern and southern runways at the western end of the Heathrow site and was opened by Queen Elizabeth II on 14 March 2008, 19 years after its inception. It opened to the public on 27 March 2008. The first passenger to enter Terminal 5 was a UK expat from Kenya who passed through security at 04:30 on the day. He was presented with a boarding pass by British Airways CEO Willie Walsh for the first departing flight, BA302 to Paris. During the two weeks after its opening, operations were disrupted by problems with the terminal's IT systems. The terminal could not catch a break in 2008 but quickly righted itself in 2009.
Built for £4.3 billion, the terminal consists of a four-story main terminal building (Concourse A) and two satellite buildings linked to the main terminal by an underground people-mover transit system. Concourse A is dedicated to British Airways' narrowbody fleet for flights around the UK and across Europe. The first satellite (Concourse B) includes dedicated stands for BA and Iberia's widebody fleet except for the Airbus A380, and the second satellite (Concourse C) includes seven dedicated aircraft stands for the A380. It became fully operational on 1 June 2011. Terminal 5 was voted Skytrax World's Best Airport Terminal 2014 in the Annual World Airport Awards. The main terminal building (Concourse A) has an area of 300,000 square meters, while Concourse B covers 60,000 square meters. It has 60 aircraft stands and capacity for 30 million passengers annually, as well as more than 100 shops and restaurants. It is also home to British Airways' flagship lounge, the Concorde Room, alongside four further British Airways-branded lounges. One of those lounges is the British Airways Arrivals Lounge, which is located landside.
This gives you, hopefully, a good idea of the background and nature of London-Heathrow Airport. We sincerely hope you enjoyed the story! Book your travel consultation to experience Heathrow yourself at Brooke In The Air Travel’s site, brookeintheairtravel.net.
