Plain English Meaning

Keeping the aircraft a safe distance away from anything it could hit on the ground, including hills, trees, towers, and tall buildings.

Full Definition

The vertical and lateral clearance maintained between an aircraft and terrain, vegetation, buildings, towers, antennas, wires, and other physical objects on or rising from the surface. In instrument flight, this clearance is built into published procedures, minimum altitudes, and ATC-assigned altitudes so that an aircraft flying the procedure correctly remains safely above and clear of all charted obstacles.

Context Anchor

Seen in instrument procedures, discussions, , , departures, and any where may not be able to see terrain or structures outside.