AA 388 then AA 2539 at Miami
Guayaquil → Miami → Boston
Timetable, Miami time
10:36AA 388 from Guayaquil at the gate
20:15AA 2539 to Boston leaves the gate
9 h 39 apart on the timetable
The last days
AA 388 and AA 2539 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.