FB 471 then FR 5993 at Madrid
Sofia → Madrid → London Stansted
Timetable, Madrid time
16:20FB 471 from Sofia at the gate
06:55FR 5993 to London Stansted leaves the gate
14 h 35 apart on the timetable, overnight
FR 5993 leaves 14 h 35 after FB 471 arrives on the timetable: more than half a day, so not a connection we count.