Originally Posted by
cfischer
huh, nope. lie-flat started in October for all flights till EOS. Before then it was almost always a 739 except for rare occasions, not sure what seasonal service you are referring to.
There have been a few times over the past few years (IIRC in the fall) where they were running 757s with lie flats for 6 or 8 weeks, sometimes mixed with 739s when they had more than one flight each way in a day. The same question about "Is UA going to start up PS on BOS-LAX?" has popped up each time since I started flying the route 3-ish years ago.
ETA: here's a
link to an article from 2015 when they did it for the summer, and I think there were similar periods in 2016 & 2017.