Dave Arquati wrote to uk.transport.london on Tue, 21 Jun 2005:

Surely if they want a really useful airport service they
should extend the 3rd rail system from south of the river to heathrow
too?

They should do that anyway, yes. That's been mooted for ages though
(known as Airtrack).

Wish they would... but they've even taken off the dedicated T123 bus
from Feltham and replaced it with I-forget-what that goes just to the
Central Bus Terminal. Useful enough, but not as reliable as before.
--
"Mrs Redboots"
http://www.amsmyth.demon.co.uk/
Website updated 23 May 2005