Definition
A defined three-dimensional volume of airspace centered on the runway and its approach path that must remain clear of all fixed objects (other than required navigation aids mounted on frangible bases) and, when active, of vehicles and aircraft. The OFZ protects aircraft during the final stages of approach, landing, and the initial climb after takeoff or a missed approach.
Plain English
A protected box of air around the runway and just above it that has to stay empty so arriving and departing aircraft have a clean path with nothing in the way.
Context Anchor
Seen in airport design, runway safety discussions, airport construction planning, and notices about objects or work near a runway.
Why Pilots Care
Ensures safe obstacle clearance during critical phases of flight, directly affecting approach minimums and runway usability.
Intuition Check
Do not read “obstacle free” as meaning the whole airport has no obstacles. In FAA use, the OFZ is a specific protected space near a runway, and a few necessary breakaway items may still be allowed inside it.
Example Sentence 1
Tower held the truck short of the runway because it would have entered the obstacle free zone while a Cessna was on short final.
Example Sentence 2
Airport operators must regularly inspect the OFZ to maintain compliance with FAA safety standards.