Originally Posted by
Infinite1K
I think it is because of lower bookings. Noticed that one of the 777HD on SFO-EWR route got upgraded to a Polaris configuration. The transition from the majority mix of HD and 752 to Polaris configurations on that route usually happens closer to Fall.
Nothing to do with lower bookings, although the TLV and DXB suspensions have enabled some more widebody slack for the time being. Pratt & Whitney has been tied up with GTF remedial work and a four-week strike that ended about a month ago, so sourcing parts for the PW4000 series (many fewer in service) has been challenging.
United's priority in the summer is the longhaul ER fleet, so 2 of the 777-200ERs with PW4090s have been parked chiefly as engine donors to support those. The non-ER have PW4077 engines which are not compatible with the ERs, hence temporarily parking N219UA and N221UA. By way of example, since the EWR-TLV was suspended, both EWR-MUC and BCN went from 777 to 787-10, and EWR-LAX/SFO have seen late swaps to Polaris-configured 777s. These changes are a direct result of this cascade.