London Heathrow Airport

London Heathrow Airport is the busiest international airport in Europe by passenger traffic and one of the most important aviation hubs in the world. LHR handles around 79 million passengers per year and sits about 15 miles west of central London. The airport is the primary hub for British Airways and Virgin Atlantic, plus a major operating base for almost every global full-service carrier. Heathrow has five terminals. Terminal 2 houses Star Alliance airlines. Terminal 3 houses most non-BA Oneworld carriers plus some SkyTeam. Terminal 4 houses SkyTeam. Terminal 5 is dedicated to British Airways and Iberia. The original Terminal 1 was closed in 2015 and its operations merged into Terminal 2. Heathrow's two parallel runways are operated in alternating mode throughout the day to distribute noise across surrounding neighborhoods. The airport has been constrained by capacity for decades, with multiple proposals for a third runway having been debated and delayed since the 2000s. Despite the constraints, LHR remains the single most important transatlantic gateway for European-North American traffic.