Someone noted over in
Status of UA's DEN-NRT thread that a 777 was subbed in for 788 on Saturday. Thought I'd ask here to see if you experts can tell me why as the other thread started years ago and is not really followed anymore
Looks like sCO flew UA143 and sUA flew UA 142 back to Denver on Sunday.
Looks like back to regular 788 with this one off 777 round trip.
FWIW, 143 frame came from SFO and 142 frame came from ORD and flew to IAD.