London Underground's (Tube) Picadilly Line goes to Heathrow Terminal 5.
This is the cheapest AND the slowest way to get to Heathrow. However, the Heathrow Express train, which costs £32 for return ticket, will get you comfortably within 20 minutes from Terminal 5 to the Paddington Station in the centere of London.
see also these links for more info:
Transport for London- http://www.tfl.gov.uk/
British Airways- http://www.terminal5.ba.com/en/to-and-from-terminal-5/london-underground/
Note: Only half of the Heathrow branch Piccadilly trains go to Terminal 5, so you will have to change at either Hatton Cross or Terminal 1,2,3 station if you aren't on this train
Which train will go to Wolverhampton from terminal 4 of London Heathrow Airport
Heathrow Terminal 3 is located in the airport in London, England. British Airways and United Airlines are located in this terminal and have flights that go around the world.
There are no direct trains from Nottingham to Heathrow. You need to go: - Nottingham to London St. Pancras - St. Pancras to Paddington (Underground, Circle line) - London St. Pancras to Heathrow. Alternatively, cheaper but slower: - Nottingham to London St. Pancras - St. Pancras to Heathrow (Underground, Piccadilly line)
About 20 minutes.
Entrance to the tube closes at 11 pm or 2300hrs
Three
You need to say which airport; London has quite a few airports - three major ones (Heathrow, Gatwick and Stansted) and several smaller ones. In general, the easiest way is to jump in a taxi - but this will be expensive. If you can get to the underground system (Heathrow has its own stations) then you can get a train to London Bridge station.
Take the Piccadilly line from Heathrow to King's Cross St Pancras (St Pancras is the Eurostar station).
Underground (tube) train.
By Either walking (landside) or catching one of the Flight Connection buses to Terminal 1 (airside) to get to the Flight connections area follow the Purple Signs after leaving your Aircraft. Planesandthings
The London Underground (Tube) serves the actual City of London, known affectionately as "The Square Mile" and Greater London. Greater London is made up of cities or 'boroughs' and are in the Coulnty of London. The tube serves many outlying cities as it stretches from the main 'circle' to places as far as Heathrow Airport but I do not believe there are any journeys more than an hour from 'Central London'.
No. You need to take the Piccadilly Line tube from Heathrow to Piccadilly Circus, then onto the Bakerloo line to Waterloo Station. From Waterloo there is a direct South West Trains service to Exeter St Davids.