but i see on continental's site flights non stop from jfk to lhr. unless you mean only regarding using united mileage that its not doable.
if thats the case, are you saying that from ewr it is doable?
Bingo
what U see out of JFK isnt a CO plane (metal) but a Virgin flight and Virgin Plane (metal) so you can get onto that if available using CO miles but not any other *A Carriers miles that doesnt have VS as their partner Again VS isnt a *A member and only a partner of CO
Yes you can use UA miles to fly on CO out of EWR if UA is allowing it, otherwise you would need to fly to IAD (Dulles, WashDC) and then catch UAs own flights to LHR. Or drive to PHL and catch USs
Now if thats a flight where US is flying its A330-200s with the flat beds in Envoy, even if you are flying in Coach Id grab that unless you can get an E+ seat on UA. the last flight Id want is COs = UA E+ is my 1st choice , then USs 330-200 planes with the flat beds since the coach seat is very comfortable on those planes and lastly a CO plane, yes IMO CO is that bad seat wise, but #1 in service and food, but seat comfort is the most important thing to me at least