Originally Posted by
LondonElite
Not sure what you mean by this, since no AA flights arrive into T5, and you wilt have access to the T5 arrivals lounge if you've arrived into T3. You do have access to the T3 arrivals lounge if you've come into T3 on a BA/AA service (do you mean this?) but as you say, not relevant for the OP.
Arriving passengers who qualify, iirc, can use either Arrivals Lounge.
But arriving after 2 PM (as well as other requirements) make this unusable.