SK 1581 then IB 547 at Madrid
Stockholm → Madrid → Porto
Timetable, Madrid time
11:10SK 1581 from Stockholm at the gate
15:40IB 547 to Porto leaves the gate
4 h 30 apart on the timetable
The last days
SK 1581 and IB 547 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.