Originally Posted by
G-BOAC
You cannot redeem AA miles US-LON. You could do BA DEN-LHR-DEN and then AA LHR-HER-LHR in theory if you have the right amount miles in both accounts.
That would be a bit tricky, seeing as BA doesn't fly LHR-HER, unless you fly LHR-MAN-HER.
There is of course LGW-HER, at the normal ungodly hours for the GT flights, such as HER 0120 LGW 0315.