Well, it’s been a long time since the two huge airlines have done a large scale grp flight together. Why not we wait for a AAVA/BAVA hub to be IFATC choice and get another member of IFATC from the airlines to host ATC for the departure/arrival airport
If EGLL has IFATC scheduled, an IFATC member from BAVA/AAVA can do the KLAX ATC, and since this a 9-10h flight, one of the timezones can sleep while the flight is an overnighter. The airlines will also fly the B77W and the A380 respectively.
I think this would be a great idea and I hope the BoDs of the VAs will start coordinating something like this…