seat-of-the-pants (sētəv-thə-pănts)
adj. Slang
► Based on or using intuition and experience rather than a plan or method; improvised: “Each has already moved beyond seat-of-the-pants management to more professional operating procedures” (Business Week).
► Performed without using instruments:
a seat-of-the-pants landing of the aircraft.

[TahlilGaran] American Dictionary ▲