QR 3641 then BA 475 at Barcelona
Catania → Barcelona → London Heathrow
Timetable, Barcelona time
20:55QR 3641 from Catania at the gate
11:45BA 475 to London Heathrow leaves the gatealso IB 3658, LA 5488, AA 6814, VY 9640
14 h 50 apart on the timetable, overnight
BA 475 leaves 14 h 50 after QR 3641 arrives on the timetable: more than half a day, so not a connection we count.