UA 3760 then BA 292 at Dulles
State College → Washington → London
Timetable, Washington time
03:21UA 3760 from State College at the gate
21:45BA 292 to London leaves the gate
18 h 24 apart on the timetable
BA 292 leaves 18 h 24 after UA 3760 arrives on the timetable: more than half a day, so not a connection we count.