Welcome to FT,
Caoimhinn!
Originally Posted by
Caoimhinn
My question is whether I am able to collect BAEC tier points/avios on flights that I have purchased through redemption of AAdvantage miles.
The reason why the answer is "no" is because as a general rule across all frequent flyer schemes, if you redeeem frequent flyer miles/points for an award flight, that flight will not earn further frequent flyer miles/points when you fly it. You normally earn miles/points only if you have paid cash for a ticket. (the cash payable for taxes, fees and charges doesn't count for the purpose of this distinction.)
There are occasional exceptions to this general rule, but I'm not aware of any in the BAEC scheme.