let fly

buy to let

To purchase a property as in investment, and to let it out for rental instead of living in it

don't let the door hit you on the way out

Used as a command to leave in haste, or to indicate that one is glad, or at least unmoved, to see the addressed person leaving.

fly blind

To do by guesswork; to feel one's way.

fly by

To pass or go past quickly, often without much interaction

fly by the seat of one's pants

To pilot an aircraft without the aid of instruments and without a flight plan, using only instinct, visual observation, and practical judgment.

fly in the face of

To act in a manner highly contrary to; to counteract or contradict.

fly in the ointment

Something (especially a minor thing) which ruins or spoils everything else, or makes it less pleasant; a nuisance or problem; a disagreeable or unpleasant detail.

fly low

To have one's fly (zipper) undone.