Originally Posted by
Time traveller
UA flights are empty because people are flying on AA instead! Loads to/from LHR have been pretty high on AA this past week, especially in premium class cabin. I believe there is a separate thread about UA losing its premium passengers to the competition.
AA seems to better manage their flights during the winter season to/from LHR as they have a revenue-sharing relationship with BA on flights to/from LHR and will reduce capacity during the winter season, rather than fly empty.
AA can more easily lend some slots to BA (or, more realistically, take over some BA TATL flying, with BA substituting flights to elsewhere) so as to preserve its LHR position. UA will find it more difficult to do this, hence downgauging is its only operational option from LHR. But it can reduce frequencies elsewhere in Europe, but seemingly chooses not to do so.