FR 2540 then QY 821 at Madrid
Bucharest → Madrid → Porto
Timetable, Madrid time
13:55FR 2540 from Bucharest at the gate
17:37QY 821 to Porto leaves the gate
3 h 42 apart on the timetable
The last days
FR 2540 and QY 821 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.