QR 3551 then BA 495 at Barcelona
Catania → Barcelona → London Heathrow
Timetable, Barcelona time
22:35QR 3551 from Catania at the gatealso IB 5803, LL 5803, VY 6119
20:45BA 495 to London Heathrow leaves the gate
22 h 10 apart on the timetable, overnight
BA 495 leaves 22 h 10 after QR 3551 arrives on the timetable: more than half a day, so not a connection we count.