BA 349 then BA 267 at Heathrow
Nice → London → Portland (Oregon)
Timetable, London time
21:05BA 349 from Nice at the gate
13:35BA 267 to Portland (Oregon) leaves the gate
16 h 30 apart on the timetable, overnight
BA 267 leaves 16 h 30 after BA 349 arrives on the timetable: more than half a day, so not a connection we count.