UA 591 then AA 1504 at Newark
Portland (Maine) → New York → Phoenix
Timetable, New York time
07:39UA 591 from Portland (Maine) at the gate
17:17AA 1504 to Phoenix leaves the gate
9 h 38 apart on the timetable
The last days
UA 591 and AA 1504 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.