AA 9781 then AA 5418 at Philadelphia
New York LaGuardia → Philadelphia → Detroit
Timetable, Philadelphia time
06:00AA 9781 from New York LaGuardia at the gate
21:59AA 5418 to Detroit leaves the gate
15 h 59 apart on the timetable
AA 5418 leaves 15 h 59 after AA 9781 arrives on the timetable: more than half a day, so not a connection we count.