It might be complete luck, but I have booked several 77W YYZ-LHR/LHR-YYZ flights for anyone of my family who is flying YYZ-LHR-YYZ (about 15 different flights so far) and there has been no plane changes so far.


I think changing to/from the 77W would be hard for AC because i) there would be a huge difference in seating capacity and ii) the scheduled flight time would be shorter than the actual. From LHR-YYZ, 77W are scheduled for around 20 minutes shorter than non 77W flights AFAIK.

Cheers