Instrument Approach Obstruction Clearance Surface

Section 16.110  Instrument Approach Obstruction Clearance Surface This surface is at a height within a terminal obstacle clearance area, including an initial approach segment, a departure area, and a circling approach area, that would result in the vertical distance between any point on the object and an established minimum instrument flight altitude within that area or segment to be less than the required obstacle clearance for that instrument approach procedure.