Originally Posted by
Aus_Mal
Yes it's covered as long as you buy a Day Travelcard which includes Zone 6.
Note that the Heathrow Express isn't available for use with a Travelcard - you'd have to catch the tube (Piccadilly line) or bus.
ALL Travelcards cover bus travel throughout the whole of London not just the zones the card is valid for.
So it is possible to take a zone 1-2 card and use it to get to Heathrow.
The shortest bus routing only takes twice as long as the Tube