Originally Posted by
dml105
So I screwed up. I purchased a J class ticket on the super sale late last year to fly US-LHR arriving at 6:20 am, and then a cheapie onward ticket on BA intra-Europe departing at 7am. I clicked on the wrong time, and didn't notice it until a month later.
Is it even possible to do T3-T5 in ~40 minutes?
C'est impossible. BA will proactively offload you if you are not airside in T5 at T-35 minutes.
If AA 100 arrives 30 minutes early, maybe.