Originally Posted by
tcualum
... the flights are going to be on separate tickets. I haven't travelled to Heathrow in years so I'm not sure how much time we need to allot for the airport transfer between flights. I would like to also feed the kids during the break. How much time should I allot between flights?
A couple of hours.
Originally Posted by
tcualum
Is it possible to transfer between flights without going through customs in London?
No. Immigration (the check, I think you are incorrectly referring to as 'customs') will be done at Heathrow as the subsequent flight is a domestic flight. Customs checks would apply too if the bags are checked to LHR. If the bags are checked through, then the customs checks would split (in theory) in two: Carry-ons would be checked at the port of entry (LHR), whereas checked bags would be controlled where they are delivered (EDI). Generally, checks of both checked bags and carry-ons are generally made at your final destination. It's not a systematic control. They may choose to pull you out or, if you have anything to declare, you'd go through the red channel.
Originally Posted by
tcualum
We'll probably be checking at least one bag so we'll need to deal with that as well? If we book a BA ticket can I call the airlines and ask them to transfer our baggage between the flights so we don't have to deal with baggage claim?
Unlikely. Even on two BA tickets, it is unlikely that they'll check the bags through.
My personal tip would be the following:
The BA flight from Austin arrives at 10 am. You head to arrivals, go through immigration, pick up your bags (in the highly likely case that they won't be checked through, drop them off at a (self)-check-in desk (you can drop them of any time on the day of travel), take the Heathrow Express or the tube into central London, have lunch somewhere, go to a museum or place of interest, and take the Heathrow Express/Tube back in the early evening to catch >8 pm flight to EDI.
That way, the risk is relatively low in case something does go wrong and you have essentially two ways out this can play out. If the AUS flight is on time, then you have a nice day out in London. If the AUS flight is late, then you'll just stay at Heathrow, but you may still make your flight to EDI.