Originally Posted by
Infinite1K
Spring/Summer is when United shifts away from true Polaris wide bodies and goes with a heavy mix of 777HD and 752s for EWR-SFO/LAX, so if they have an extra 789 frame, doubt they would be using it on that route. I would think the reason for the 789 instead of a 763 is that they could use the 763 on one of the other routes that wouldn’t demand as much premium fares.
As a business market, LHR does not drive as much premium leisure demand as Southern Europe in the summer, and business demand dips a bit too. Simultaneously, there is greater demand for Y. While the 76L is a great platform for EWR-LHR most of the year, I think United has found that it does not have enough Y capacity in the market for the summer, hence the upgauge now that it has some more 787s available.
While I am hopeful for the 78P and think EWR-LHR will get it eventually, I'm not sure how the aircraft rotation would work out for this flight, so it is probably premature.