IB 2471 then BA 481 at Barcelona
Leon → Barcelona → London Heathrow
Timetable, Barcelona time
21:35IB 2471 from Leon at the gatealso LL 3101, VY 5871, QR 6959
14:40BA 481 to London Heathrow leaves the gatealso IB 3663, AA 6819, VY 9559, QR 9800
17 h 05 apart on the timetable, overnight
BA 481 leaves 17 h 05 after IB 2471 arrives on the timetable: more than half a day, so not a connection we count.