Definition
The Runway Obstacle Free Zone (OFZ) is a defined volume of airspace centered above the runway and extending along its full length, kept clear of taxiing, parked, or holding aircraft and of any non-essential fixed objects. It protects aircraft during the final portion of approach, landing, takeoff, and the initial climb. Only frangible objects required for air navigation or aircraft ground maneuvering may be located within it.
Plain English
A protected box of air directly above the runway and along its sides that must stay clear of aircraft and obstacles, so planes taking off or landing have a safe space.
Context Anchor
Seen in airport design, runway safety, and obstruction-clearance discussions.
Derivation
From 'obstacle' (something in the way) and 'free zone' (an area kept clear). The name describes the function literally: a zone kept free of obstacles.
Why Pilots Care
It keeps critical airspace clear during the most vulnerable phases of flight, directly supporting safe takeoffs and landings especially in low visibility or when operating at minimums.
Grounding Statement
Picture a clear invisible box around the runway that protects the space an aircraft needs close to the ground.
Intuition Check
Do not read “free” as meaning the runway is available to use. Here, “free” means clear of obstacles.
Example Sentence 1
Tower held the departure on the taxiway because a maintenance truck was still inside the runway OFZ.
Example Sentence 2
Before issuing a takeoff clearance in fog, the controller verified that the Runway OFZ remained clear of any temporary obstacles.