on the wing
on the wing {adv.} or {adj. phr.}
1. In the air; while flying.
The duck flew away, but John shot it on the wing.
2. {informal}
In constant motion; always very busy.
Susan was on the wing doing things to get ready for her trip.
Mr. Jones had a busy schedule and his secretary had to catch him on the wing to sign the letters.
Syn.: ON THE FLY.
3. {informal}
Moving from one place to another; traveling; going somewhere.
Mary's husband is a traveling salesman and he's always on the wing.
They stayed in France for a week and then they were on the wing again.
Categories:
Source: A Dictionary of American Idioms