(I've) got to take off
I need to leave. Well, I've got to take off. It was lovely to see you, as always. Got to take off before I miss my train!
(I've) got to take off.
Fig. a phrase announcing one's need to depart. (See also (I) have to shove off for other possible variations.) Mary: Got to take off. Bye. Bob: Leaving so soon? Mary: Yes. Time to go. Bob: Bye. "Look at the time. I've got to take off!" shrieked Alice.