Heathrow Express is a train service in London that provides an airport rail link service between Paddington station and Heathrow Airport. It is operated by the Heathrow Express Operating Company, owned by the same company which owns Heathrow Airport itself, and the first train ran on 23 June 1998.
The Heathrow Express service runs every 15 minutes throughout the day and evening, seven days a week. It runs non-stop between Paddington and the airport. (The Heathrow Connect uses the same route but make some stops in between.) At the airport, trains from Paddington stop at two stations, both of which are located underground: Heathrow Central (for terminals 2 and 3) and Heathrow Terminal 5. There is also a shuttle train that goes between Heathrow Central and a station at Terminal 4, which is also underground. The 14 trains used on services between Paddington and Heathrow are Class 332s, while the shuttle service to Terminal 4 uses one Class 360.
Heathrow Express is not part of National Rail, and is not run as a franchise, even though it shares track with National Rail trains for much of its journey and ends its trip at a London mainline station.