Definition
A defined volume of airspace centered on the runway and extended approach area at airports served by a precision instrument approach, which must be kept clear of all fixed obstacles, parked aircraft, and surface vehicles to protect aircraft conducting low-visibility approaches and missed approaches. It is a more restrictive standard than the standard Obstacle Free Zone and applies where Category II or III precision approaches are authorized.
Plain English
A protected piece of airspace around the runway and the final approach path that has to stay completely empty of obstacles, parked aircraft, and ground vehicles, so that an aircraft flying a precision instrument approach in poor visibility has guaranteed clear space.
Context Anchor
You may see this term in airport design, runway safety, instrument approach, and air traffic control discussions.
Derivation
"Precision" here points to precision instrument approaches (ILS approaches that provide both lateral and vertical guidance). The zone is more tightly controlled than the standard Obstacle Free Zone because precision approaches bring aircraft lower and closer to the runway in worse visibility, so the protected airspace must be stricter.
Why Pilots Care
Protects the final approach path so the aircraft maintains required obstacle clearance when flying a precision glidepath down to decision altitude.
Analogy
Think of it like keeping the area in front of a garage door clear when a car is pulling in. The driver needs that protected space at the critical moment, even if the space is empty most of the time.
Intuition Check
Precision does not mean the zone itself is perfectly measured or error-free. Here, precision refers to the kind of approach being protected: one with exact vertical guidance down toward the runway.
Example Sentence 1
The airport's Precision Obstacle Free Zone must remain clear of vehicles and parked aircraft whenever a Category II approach is in use.
Example Sentence 2
Airport maintenance delayed snow removal on the first 200 feet of runway until the Precision Obstacle Free Zone was confirmed clear.