Originally Posted by
Hedwig
What about AMS? Same hall for arriving and departing so walk off the plane, turn around and get back on the same plane back to LHR. Worth it to see the look on the crew's face as they welcome you back on board.
I haven't been to MAN for ages so I can't comment, but EDI, GLA and ABZ would all be good for a quick turnaround as arrivals / departures are mixed, so if you already have your BP for the return then just walk off the flight from LON and join the crowd at the gate for the return.
And if an earlier flight is delayed then maybe you could ask to be moved to a flight that departs before you arrived!