Originally Posted by House
Your baggage allowance for LHR-MAN is exactly half of the AA baggage allowance (1 piece of baggage allowed). You will likely have to pay an excess charge (likely to be less than £20 but I don't know the exact rate).
Excess baggage, if charged, will a fixed rate of £15 per piece to a max of 32kg (70lb). Free checked baggage allowance on UK Domestic is one piece, again not exceeding 32kg