Originally Posted by
littlefish
I'd always understood BA T5 arrivals was for BA passengers only (WT, WT+ get in on the Gold Card).
This at ba.com seems to suggest the same:
http://www.britishairways.com/en-gb/.../lounge-access
Arriving US into T3 provides the distinctly runners-up prize of AA arrivals lounge.
That was my understanding as well.