CX 1750 then IB 725 at Madrid
Buenos Aires → Madrid → London Heathrow
Timetable, Madrid time
04:05CX 1750 from Buenos Aires at the gatealso BA 4252, QR 6919
17:20IB 725 to London Heathrow leaves the gatealso LA 1704, VY 5180, BA 7058
13 h 15 apart on the timetable
IB 725 leaves 13 h 15 after CX 1750 arrives on the timetable: more than half a day, so not a connection we count.