Plain English Meaning

Keeping enough room between the airplane and anything you could hit -- trees, towers, wires, hills, or buildings -- both below and around you.

Full Definition

The vertical and horizontal separation maintained between an aircraft and any terrain, structures, vegetation, towers, wires, or other objects that could be struck during flight. In ground reference maneuvers and low-altitude flight, obstruction clearance refers specifically to selecting an altitude and ground track that keep the airplane safely above and clear of such objects throughout the maneuver.

Context Anchor

In drift and ground track control, obstruction clearance matters when wind pushes the airplane sideways from the intended path near the .