5/19/22
Pilot/Controller Glossary
PRECIPITATION
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Any or all forms of water
particles (rain, sleet, hail, or snow) that fall from the
atmosphere and reach the surface.
PRECIPITATION RADAR WEATHER DESCRIP-
TIONS
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Existing radar systems cannot detect
turbulence. However, there is a direct correlation
between the degree of turbulence and other weather
features associated with thunderstorms and the
weather radar precipitation intensity. Controllers will
issue (where capable) precipitation intensity as
observed by radar when using weather and radar
processor (WARP) or NAS ground
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based digital
radars with weather capabilities. When precipitation
intensity information is not available, the intensity
will be described as UNKNOWN. When intensity
levels can be determined, they shall be described as:
a.
LIGHT (< 26 dBZ)
b.
MODERATE (26 to 40 dBZ)
c.
HEAVY (> 40 to 50 dBZ)
d.
EXTREME (> 50 dBZ)
(Refer to AC 00
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45, Aviation Weather Services.)
PRECISION APPROACH
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(See PRECISION APPROACH PROCEDURE.)
PRECISION APPROACH PROCEDURE
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A
standard instrument approach procedure in which an
electronic glideslope or other type of glidepath is
provided; e.g., ILS, PAR, and GLS.
(See INSTRUMENT LANDING SYSTEM.)
(See PRECISION APPROACH RADAR.)
PRECISION APPROACH RADAR
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Radar equip-
ment in some ATC facilities operated by the FAA
and/or the military services at joint-use civil/military
locations and separate military installations to detect
and display azimuth, elevation, and range of aircraft
on the final approach course to a runway. This
equipment may be used to monitor certain non
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radar
approaches, but is primarily used to conduct a
precision instrument approach (PAR) wherein the
controller issues guidance instructions to the pilot
based on the aircraft’s position in relation to the final
approach course (azimuth), the glidepath (elevation),
and the distance (range) from the touchdown point on
the runway as displayed on the radar scope.
(See GLIDEPATH.)
(See PAR.)
(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.
PRECISION OBSTACLE FREE ZONE (POFZ)
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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
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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)
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A self
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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
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.
PREFERRED IFR ROUTES
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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., and are also
available at https://www.fly.faa.gov/rmt/nfdc_pre-
ferred_routes_database.jsp. If a flight is planned to or
PCG P
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