Key facts about Heathrow Airport, one of the world's busiest hubs

(Reuters) -Britain's Heathrow Airport, a major global travel hub, said it would be closed for all of Friday after a huge fire at a nearby electrical substation wiped out its power, disrupting flight schedules around the world.

Here are some facts about the world's fourth-busiest international airport:

KEY NUMBERS:

-- Heathrow serves more than 230 destinations in nearly 90 countries.

-- Ninety airlines have made Heathrow their base, including British Airways, Virgin Atlantic and Lufthansa.

-- According to the group's traffic summary, 5.7 million passengers travelled through Heathrow in February 2025, making it the busiest February on record. Passenger numbers amounted to 84.1 million from March 2024 to February 2025.

-- There are two main runways. The northern one is 3,902 metres long. The southern is 3,658 metres.

-- The airport will submit its proposal for a third runway this summer, weeks after the British government granted its support to the project citing its potential to boost trade and economic growth.

-- Heathrow is operating at 99% capacity and risks being overtaken by European rivals. Its two runways compare with four each at Paris' Charles de Gaulle and Frankfurt Airport, and six at Amsterdam's Schiphol.

-- The airport is owned and operated by Heathrow Airport Holdings, whose owners include Ardian, Qatar Investment Fund and Saudi Arabia's Public Investment Fund.

-- There are around 475,000 total aircraft movements through Heathrow annually.

-- The most popular destination out of Heathrow is New York.

-- More than 90,000 people work at the airport, the UK's largest single-site employer.

HISTORY:

-- The airport is named after the village or hamlet of Heathrow, which used to be roughly where Terminal 3 now stands.

-- It began as a tented village in 1946 serving 18 destinations with a handful of airlines making 9,000 flights a year.

-- The first departure was on New Year's Day 1946 to Buenos Aires via Lisbon, the first refuelling stop on a long-haul flight to open up Britain's first air link with South America.

-- Heathrow's first terminal for short haul flights opened in 1955. Originally known as the Europa Building, it is now known as Terminal 2.

-- Terminal 1 was formally opened in 1969 by Queen Elizabeth and was closed in June 2015. Terminal 3 opened in 1961 and Terminal 4 in 1986.

-- Terminal 5 opened in 2008. The public inquiry into its construction was the longest in British planning history, lasting nearly four years. 

(Reporting by David Cutler, Alban Kacher, Alberto Chiumento; Editing by Raju Gopalakrishnan and Hugh Lawson)