The Precision Obstacle Free Zone – POFZ is a section of airspace above an area beginning at the runway threshold, at the threshold elevation, and centered on the extended runway centerline. The standard Precision Obstacle Free Zone - POFZ is 200 feet (60 meters) long and 800 feet (240 meters) wide. The POFZ must be clear when an aircraft on a vertically guided final approach is within 2 nautical miles (NM) of the runway threshold and the reported ceiling is below 250 feet or visibility less than 3/4 statute mile (SM) (or runway visual range below 4,000 feet).
The Precision Obstacle Free Zone – POFZ is considered clear even if the wing of the aircraft holding on a taxiway waiting for runway clearance penetrates the POFZ; however, neither the fuselage nor the tail may infringe on the POFZ
For approaching aircraft, in the event that taxiing/parked aircraft or vehicle is not clear of the POFZ, air traffic control will provide advisories to the approaching aircraft regarding the position of the offending aircraft/vehicle. In this case the pilot of the approaching aircraft must decide to continue or abort the approach. When the reported ceiling is below 800 feet or visibility less than 2 SM, departing aircraft must do the following. When there is an air traffic control tower (ATCT) in operation, plan to hold at the ILS hold line and hold as directed by air traffic control. When there is no operating ATCT, honor the ILS hold line and do not taxi into position and takeoff if there is an approaching aircraft within 2 NM of the runway threshold.