It depends on where you are flying from (into LHR) or to (from CDG) for the aircraft type. From/to SFO, UA has 1 daily nonstop CDG flight using a 777, to/from LHR they have 2 daily nonstops (one 777, and one 747-400)-I think that is still true. UA at CDG would use CDG1 (AF's expansive terminals are on the other side at CDG2-built in the late 70's, but still continually added onto). Both CDG1 and CDG2 are completely different from each other in looks. I always fly AF, but I have always had a fondness for the CDG1 terminal with its round building and transparent escalator tubes going every which way. It may be getting old (built in late 60's?), but it still is a fascinating place and was/is kind of futuristic in a sense. my opnion. UA has several flights from other major cities to LHR/CDG so others might be able to answer much better!