Don't walk is what I say. Take the free Heathrow Express between Terminal 1 and 5!
about 8km! free shutle bus every 10 min.
Between Terminals 1, 2 and 3 Heathrow Terminals 1, 2 and 3 are close together at the centre of the airport and linked by a pedestrian underpass with moving walkways. Just follow the signs for your...
i dont think there is a terminal 8 not in uk The distance from one terminal to the next would be different from one airport to another.
About 20 minutes.