Originally Posted by 81romeo

I've done exactly the same thing many times, with or without checked luggage.

Your AZ flight will arrive at T1, I usually go outside and walk to the T3 arrivals bit (it's a 3 minutes walk). Once you arrive at T3 arrivals get the escalator up to departures.

Once you clear security and customs, your BA flight will either leave from the satellite or from the new part of the terminal (which means no need to take the little train).

If you are Silver you can use the fast track service at T3 which is always a breeze. The BA lounge is average, best part is the smoking room (if you are a smoker) and the Prosecco. Food is a poor show.