The obstacle-free zone (OFZ) is a 3D volume of airspace below 150 feet (46 m), above the established airport elevation which protects for the transition of aircraft to and from the runway. The Obstacle Free Zone (OFZ) clearing standard precludes taxiing and parked airplanes and object penetrations, except for frangible navigation aid (NAVAID) locations that are fixed by function. It is centered above the runway and the extended runway centerline and is intended to provide clearance protection for aircraft landing or taking off from the runway and for missed approaches. The OFZ is subdivided into:
- Runway OFZ, the airspace above a surface centered on the runway centerline
- Inner-approach OFZ, centered on the extended runway centerline and applicable only to runways with an approach lightning system
- Inner-transitional OFZ, the airspace above the surface located on the outer edges of the runway OFZ ad the inner-approach OFZ and applicable only to runways with an approach visibility minimum lower than ¾ of mile
Famous quotes containing the words obstacle, free and/or zone:
“But this we know, the obstacle that checked
And tripped the body, shot the spirit on
Further than target ever showed or shone.”
—Robert Frost (1874–1963)
“And anyone is free to condemn me to death
If he leaves it to nature to carry out the sentence.
I shall will to the common stock of air my breath
And pay a death tax of fairly polite repentance.”
—Robert Frost (1874–1963)
“There was a continuous movement now, from Zone Five to Zone Four. And from Zone Four to Zone Three, and from us, up the pass. There was a lightness, a freshness, and an enquiry and a remaking and an inspiration where there had been only stagnation. And closed frontiers. For this is how we all see it now.”
—Doris Lessing (b. 1919)