CA 987 then DL 1739 at LAX
Beijing → Los Angeles → Phoenix
Timetable, Los Angeles time
10:00CA 987 from Beijing at the gate
14:20DL 1739 to Phoenix leaves the gate
4 h 20 apart on the timetable
The last days
CA 987 and DL 1739 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.