and the distance (range) from the touchdown point on  the runway as displayed on the radar scope.  Note: The abbreviation “PAR” is also used to  denote preferential arrival routes in ARTCC  computers.  (See GLIDEPATH.)  (See PAR.)  (See PREFERENTIAL ROUTES.)  (See ICAO term PRECISION APPROACH  RADAR.)  (Refer to AIM.)  PRECISION APPROACH RADAR [ICAO]- Pri- mary radar equipment used to determine the position  of an aircraft during final approach, in terms of lateral  and vertical deviations relative to a nominal approach  path, and in range relative to touchdown.  Note: Precision approach radars are designed to  enable pilots of aircraft to be given guidance by  radio communication during the final stages of the  approach to land.  PRECISION OBSTACLE FREE ZONE (POFZ)- An 800 foot wide by 200 foot long area centered on  the runway centerline adjacent to the threshold  designed to protect aircraft flying precision  approaches from ground vehicles and other aircraft  when ceiling is less than 250 feet or visibility is less  than 3/4 statute mile (or runway visual range below  4,000 feet.)  PRECISION RUNWAY MONITOR (PRM)  SYSTEM- Provides air traffic controllers  monitoring the NTZ during simultaneous close  parallel PRM approaches with precision, high update  rate secondary surveillance data. The high update rate  surveillance sensor component of the PRM system is  only required for specific runway or approach course  separation. The high resolution color monitoring  display, Final Monitor Aid (FMA) of the PRM  system, or other FMA with the same capability,  presents NTZ surveillance track data to controllers  along with detailed maps depicting approaches and  no transgression zone and is required for all  simultaneous close parallel PRM NTZ monitoring  operations.  (Refer to AIM)  PREDICTIVE WIND SHEAR ALERT SYSTEM  (PWS)- A self-contained system used on board some  aircraft to alert the flight crew to the presence of a  potential wind shear. PWS systems typically monitor  3 miles ahead and 25 degrees left and right of the  PREFERRED IFR ROUTES- Routes established  between busier airports to increase system efficiency  and capacity. They normally extend through one or  more ARTCC areas and are designed to achieve  balanced traffic flows among high density terminals.  IFR clearances are issued on the basis of these routes  except when severe weather avoidance procedures or  other factors dictate otherwise. Preferred IFR Routes  are listed in the Chart Supplement U.S. If a flight is  planned to or from an area having such routes but the  departure or arrival point is not listed in the Chart  Supplement U.S., pilots may use that part of a  (See PREFERRED IFR ROUTES.)  c.  Preferential Departure and Arrival Route  (PDAR). A route between two terminals which are  within or immediately adjacent to one ARTCC's area.  PDARs are not synonymous with Preferred IFR  Routes but may be listed as such as they do  accomplish essentially the same purpose.  b.  Preferential Arrival Route (PAR). A specific  arrival route from an appropriate en route point to an  airport or terminal area. It may be included in a  Standard Terminal Arrival (STAR) or a Preferred IFR  Route. The abbreviation “PAR” is used primarily  within the ARTCC and should not be confused with  the abbreviation for Precision Approach Radar.  a.  Preferential Departure Route (PDR). A specific  departure route from an airport or terminal area to an  en route point where there is no further need for flow  control. It may be included in an Instrument  Departure Procedure (DP) or a Preferred IFR Route.  PREFERENTIAL ROUTES- Preferential routes  (PDRs, PARs, and PDARs) are adapted in ARTCC  computers to accomplish inter/intrafacility controller  coordination and to assure that flight data is posted at  the proper control positions. Locations having a need  for these specific inbound and outbound routes  normally publish such routes in local facility  bulletins, and their use by pilots minimizes flight  plan route amendments. When the workload or traffic  situation permits, controllers normally provide radar  vectors or assign requested routes to minimize  circuitous routing. Preferential routes are usually  confined to one ARTCC's area and are referred to by  the following names or acronyms:  aircraft's heading at or below 1200' AGL. Departing  flights may receive a wind shear alert after they start  the takeoff roll and may elect to abort the takeoff.  Aircraft on approach receiving an alert may elect to  go around or perform a wind shear escape maneuver.  Pilot/Controller Glossary Pilot/Controller Glossary  8/15/19 1/30/20  PCG P-3 