Longest Runway in the UK London Heathrow 09L/27R at 12,799ft x 164ft (3,902m x 50m) is currently the longest active runway in the UK.

The UK airport with the longest single runway is London Heathrow Airport (LHR).

Its northern runway (09L/27R) is 3,902 metres (12,802 feet) long, and its southern runway (09R/27L) is 3,658 metres (12,005 feet) long.

However, if you are asking about the airport with the longest possible runway available for use, that title goes to a military airfield:

• RAF Brize Norton in Oxfordshire has a runway that is 3,649 metres (11,972 feet) long. While slightly shorter than Heathrow’s longest, it’s worth noting as a major long runway.

For context, here are other UK airports with notably long runways:

• Manchester Airport (MAN): Runway 2 is 3,048 metres (10,000 ft).
• London Gatwick (LGW): Its main runway is 3,316 metres (10,879 ft).
• London Stansted (STN): Its single runway is 3,048 metres (10,000 ft).

Important Distinction: Civilian Airport: Heathrow has the longest runways. Overall (including military): RAF Brize Norton is comparable, but Heathrow’s northern runway is still the longest paved runway in the UK.

Heathrow’s exceptionally long runways are necessary to accommodate fully laden, large long-haul aircraft (like the Boeing 747 and Airbus A380) on hot days or when flying to distant destinations, as they require more runway length to take off.