This one is available at various times of the year. I found great availability over the holiday season (12/16/16-1/2/17)

Also sometimes there are good deals to SIN, PEK, BKK, although in some cases with very long layovers in LHR or HEL.

Flights are YYC-LHR and LHR-YYC on BA (AY codeshare), with the remaining all on AY.

Still, not a bad deal if you're looking to go to Asia for the holidays while getting a nice boost towards AA EXP, as you'll earn 1.5x EQM on AA.