Are you sure? I have heard rumours that you can travel between
Heathrow Terminal 4 and Heathrow Terminals 1,2,3 (via Hatton Cross if
necessary) for free - I believe you have to show airline tickets or
other proof of travel though. Having never attempted it, I don't even
know if it's true or not.

I remember doing that journey a few years ago and I can remember there being
staff checking Tickets
--
To reply direct, remove NOSPAM and replace with railwaysonline
For Railway Information, News & Photos check out the Award Winning Railways
Online at http://www.railwaysonline.co.uk
"Loving First Great Western Link since 2004"