UA 3911 then UA 331 at Houston
Washington → Houston → Washington National
Timetable, Houston time
00:06UA 3911 from Washington at the gate
16:55UA 331 to Washington National leaves the gate
16 h 49 apart on the timetable
UA 331 leaves 16 h 49 after UA 3911 arrives on the timetable: more than half a day, so not a connection we count.