QR 3692 then BA 473 at Barcelona
Rome → Barcelona → London Heathrow
Timetable, Barcelona time
17:05QR 3692 from Rome at the gate
10:15BA 473 to London Heathrow leaves the gate
17 h 10 apart on the timetable, overnight
BA 473 leaves 17 h 10 after QR 3692 arrives on the timetable: more than half a day, so not a connection we count.