My wife and I are landing in Heathrow on Oct. 9th at 13:50 flying Air Canada from Vancouver, arriving terminal 3. I'm assuming (am I living in a fantasy world?) that the flight will arrive pretty much on time. After the flight lands, how much time should I allow to get our luggage and clear customs? Following this we are heading directly to Cardiff (not what we had originally planned, but now committed). Would we be better off taking the train or the bus? Are the bus and train easily assessable from Heathrow? I believe they are from what I have read, however would like confirmation. My thought was to make reservations on either the train or bus and allow 3 hours after landing to ensure that we make the time. Is this too much, just right or not enough. I'm leaning towards the bus right now,as there is no bus change. If we happened to arrive early for which ever we reserved on, would we be able to take an earlier ride? If we arrive late will our tickets be worthless. I can't seem to find an answer to these questions on the websites. Thanks in advance for any help you can give, it is most appreciated.