2/28/19 Pilot/Controller Glossary PILOT/CONTROLLER GLOSSARY · Pilot/Controller Glossary 3/29/18 PCG C−4 CLEARED THROUGH− ATC authorization for an aircraft to make intermediate

Pilot/Controller Glossary2/28/19

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PILOT/CONTROLLERGLOSSARY

PURPOSE

a. This Glossary was compiled to promote a common understanding of the terms used in the Air TrafficControl system. It includes those terms which are intended for pilot/controller communications. Those termsmost frequently used in pilot/controller communications are printed in bold italics. The definitions are primarilydefined in an operational sense applicable to both users and operators of the National Airspace System. Use ofthe Glossary will preclude any misunderstandings concerning the system’s design, function, and purpose.

b. Because of the international nature of flying, terms used in the Lexicon, published by the InternationalCivil Aviation Organization (ICAO), are included when they differ from FAA definitions. These terms arefollowed by “[ICAO].” For the reader’s convenience, there are also cross references to related terms in other partsof the Glossary and to other documents, such as the Code of Federal Regulations (CFR) and the AeronauticalInformation Manual (AIM).

c. This Glossary will be revised, as necessary, to maintain a common understanding of the system.

EXPLANATION OF CHANGES

d. Terms Added:ICAO 3LDICAO Term ICAO Three Letter DesignatorUNCONTROLLED AIRSPACE

e. Terms Deleted:IFIMINTERNATIONAL FLIGHT INFORMATION MANUAL

f. Terms Modified:CLASS G AIRSPACEINTERNATIONAL CIVIL AVIATION ORGANIZATION [ICAO]NOTICES TO AIRMEN PUBLICATION

g. Editorial/format changes were made where necessary. Revision bars were not used due to the insignificantnature of the changes.

2/28/19 Pilot/Controller Glossary

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PCG−1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9/13/18 PCG−1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2/28/19

PCG C−3 and PCG C−4 . . . . . . . . . . . . . . . . . 3/29/18 PCG C−3 and PCG C−4 . . . . . . . . . . . . . . . . 2/28/19

PCG C−5 through PCG C−9 . . . . . . . . . . . . . 9/13/18 PCG C−5 through PCG C−9 . . . . . . . . . . . . 2/28/19

PCG I−1 through PCG I−6 . . . . . . . . . . . . . . . 3/29/18 PCG PCG I−1 through PCG I−6 . . . . . . . . . 2/28/19

PCG N−3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9/13/18 PCG N−3 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9/13/18

PCG N−4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9/13/18 PCG N−4 . . . . . . . . . . . . . . . . . . . . . . . . . . . 2/28/19

PCG U−1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3/29/18 PCG U−1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 2/28/19


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CLASS D AIRSPACE−(See CONTROLLED AIRSPACE.)

CLASS E AIRSPACE−(See CONTROLLED AIRSPACE.)

CLASS G AIRSPACE− Airspace that is notdesignated in 14 CFR Part 71 as Class A, Class B,Class C, Class D, or Class E controlled airspace isClass G (uncontrolled) airspace.

(See UNCONTROLLED AIRSPACE.)

CLEAR AIR TURBULENCE (CAT)− Turbulenceencountered in air where no clouds are present. Thisterm is commonly applied to high-level turbulenceassociated with wind shear. CAT is often encounteredin the vicinity of the jet stream.

(See WIND SHEAR.)(See JET STREAM.)

CLEAR OF THE RUNWAY−

a. Taxiing aircraft, which is approaching arunway, is clear of the runway when all parts of theaircraft are held short of the applicable runwayholding position marking.

b. A pilot or controller may consider an aircraft,which is exiting or crossing a runway, to be clear ofthe runway when all parts of the aircraft are beyondthe runway edge and there are no restrictions to itscontinued movement beyond the applicable runwayholding position marking.

c. Pilots and controllers shall exercise goodjudgement to ensure that adequate separation existsbetween all aircraft on runways and taxiways atairports with inadequate runway edge lines orholding position markings.

CLEARANCE−(See AIR TRAFFIC CLEARANCE.)

CLEARANCE LIMIT− The fix, point, or location towhich an aircraft is cleared when issued an air trafficclearance.

(See ICAO term CLEARANCE LIMIT.)

CLEARANCE LIMIT [ICAO]− The point to whichan aircraft is granted an air traffic control clearance.

CLEARANCE VOID IF NOT OFF BY (TIME)−Used by ATC to advise an aircraft that the departureclearance is automatically canceled if takeoff is notmade prior to a specified time. The pilot must obtain

a new clearance or cancel his/her IFR flight plan if notoff by the specified time.

(See ICAO term CLEARANCE VOID TIME.)

CLEARANCE VOID TIME [ICAO]− A timespecified by an air traffic control unit at which aclearance ceases to be valid unless the aircraftconcerned has already taken action to complytherewith.

CLEARED APPROACH− ATC authorization for anaircraft to execute any standard or special instrumentapproach procedure for that airport. Normally, anaircraft will be cleared for a specific instrumentapproach procedure.

(See CLEARED (Type of) APPROACH.)(See INSTRUMENT APPROACHPROCEDURE.)

(Refer to 14 CFR Part 91.)(Refer to AIM.)

CLEARED (Type of) APPROACH− ATC authoriza-tion for an aircraft to execute a specific instrumentapproach procedure to an airport; e.g., “Cleared ILSRunway Three Six Approach.”

(See APPROACH CLEARANCE.)(See INSTRUMENT APPROACHPROCEDURE.)


CLEARED AS FILED− Means the aircraft is clearedto proceed in accordance with the route of flight filedin the flight plan. This clearance does not include thealtitude, DP, or DP Transition.

(See REQUEST FULL ROUTE CLEARANCE.)(Refer to AIM.)

CLEARED FOR TAKEOFF− ATC authorizationfor an aircraft to depart. It is predicated on knowntraffic and known physical airport conditions.

CLEARED FOR THE OPTION− ATC authoriza-tion for an aircraft to make a touch-and-go, lowapproach, missed approach, stop and go, or full stoplanding at the discretion of the pilot. It is normallyused in training so that an instructor can evaluate astudent’s performance under changing situations.Pilots should advise ATC if they decide to remain onthe runway, of any delay in their stop and go, delayclearing the runway, or are unable to comply with theinstruction(s).

(See OPTION APPROACH.)(Refer to AIM.)


Pilot/Controller Glossary 3/29/18

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CLEARED THROUGH− ATC authorization for anaircraft to make intermediate stops at specifiedairports without refiling a flight plan while en routeto the clearance limit.

CLEARED TO LAND− ATC authorization for anaircraft to land. It is predicated on known traffic andknown physical airport conditions.

CLEARWAY− An area beyond the takeoff runwayunder the control of airport authorities within whichterrain or fixed obstacles may not extend abovespecified limits. These areas may be required forcertain turbine-powered operations and the size andupward slope of the clearway will differ depending onwhen the aircraft was certificated.

(Refer to 14 CFR Part 1.)

CLIMB TO VFR− ATC authorization for an aircraftto climb to VFR conditions within Class B, C, D, andE surface areas when the only weather limitation isrestricted visibility. The aircraft must remain clear ofclouds while climbing to VFR.

(See SPECIAL VFR CONDITIONS.)

(Refer to AIM.)

CLIMBOUT− That portion of flight operationbetween takeoff and the initial cruising altitude.

CLIMB VIA– An abbreviated ATC clearance thatrequires compliance with the procedure lateral path,associated speed restrictions, and altitude restrictionsalong the cleared route or procedure.

CLOSE PARALLEL RUNWAYS− Two parallelrunways whose extended centerlines are separated byless than 4,300 feet and at least 3000 feet (750 feet forSOIA operations) for which ATC is authorized toconduct simultaneous independent approach opera-tions. PRM and simultaneous close parallel appear inapproach title. Dual communications, special pilottraining, an Attention All Users Page (AAUP), NTZmonitoring by displays that have aural and visualalerting algorithms are required. A high update ratesurveillance sensor is required for certain runway orapproach course spacing.

CLOSED RUNWAY− A runway that is unusable foraircraft operations. Only the airport management/military operations office can close a runway.

CLOSED TRAFFIC− Successive operations involv-ing takeoffs and landings or low approaches wherethe aircraft does not exit the traffic pattern.

CLOUD− A cloud is a visible accumulation ofminute water droplets and/or ice particles in theatmosphere above the Earth’s surface. Cloud differsfrom ground fog, fog, or ice fog only in that the latterare, by definition, in contact with the Earth’s surface.

CLT−(See CALCULATED LANDING TIME.)

CLUTTER− In radar operations, clutter refers to thereception and visual display of radar returns causedby precipitation, chaff, terrain, numerous aircrafttargets, or other phenomena. Such returns may limitor preclude ATC from providing services based onradar.

(See CHAFF.)(See GROUND CLUTTER.)(See PRECIPITATION.)(See TARGET.)(See ICAO term RADAR CLUTTER.)

CMNPS−(See CANADIAN MINIMUM NAVIGATIONPERFORMANCE SPECIFICATION AIRSPACE.)

COASTAL FIX− A navigation aid or intersectionwhere an aircraft transitions between the domesticroute structure and the oceanic route structure.

CODES− The number assigned to a particularmultiple pulse reply signal transmitted by atransponder.

(See DISCRETE CODE.)

COLD TEMPERATURE COMPENSATION− Anaction on the part of the pilot to adjust an aircraft’sindicated altitude due to the effect of coldtemperatures on true altitude above terrain versusaircraft indicated altitude. The amount ofcompensation required increases at a greater rate witha decrease in temperature and increase in heightabove the reporting station.

COLLABORATIVE TRAJECTORY OPTIONSPROGRAM (CTOP)− CTOP is a traffic managementprogram administered by the Air Traffic ControlSystem Command Center (ATCSCC) that managesdemand through constrained airspace, while consid-ering operator preference with regard to both routeand delay as defined in a Trajectory Options Set(TOS).



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COMBINED CENTER-RAPCON− An air trafficfacility which combines the functions of an ARTCCand a radar approach control facility.

(See AIR ROUTE TRAFFIC CONTROLCENTER.)

(See RADAR APPROACH CONTROLFACILITY.)

COMMON POINT− A significant point over whichtwo or more aircraft will report passing or havereported passing before proceeding on the same ordiverging tracks. To establish/maintain longitudinalseparation, a controller may determine a commonpoint not originally in the aircraft’s flight plan andthen clear the aircraft to fly over the point.

(See SIGNIFICANT POINT.)

COMMON PORTION−(See COMMON ROUTE.)

COMMON ROUTE− That segment of a NorthAmerican Route between the inland navigationfacility and the coastal fix.

OR

COMMON ROUTE− Typically the portion of aRNAV STAR between the en route transition endpoint and the runway transition start point; however,the common route may only consist of a single pointthat joins the en route and runway transitions.

COMMON TRAFFIC ADVISORY FREQUENCY(CTAF)− A frequency designed for the purpose ofcarrying out airport advisory practices whileoperating to or from an airport without an operatingcontrol tower. The CTAF may be a UNICOM,Multicom, FSS, or tower frequency and is identifiedin appropriate aeronautical publications.

(See DESIGNATED COMMON TRAFFICADVISORY FREQUENCY (CTAF) AREA.)

(Refer to AC 90-42, Traffic Advisory Practices atAirports Without Operating Control Towers.)

COMPASS LOCATOR− A low power, low ormedium frequency (L/MF) radio beacon installed atthe site of the outer or middle marker of an instrumentlanding system (ILS). It can be used for navigation atdistances of approximately 15 miles or as authorizedin the approach procedure.

a. Outer Compass Locator (LOM)− A compasslocator installed at the site of the outer marker of aninstrument landing system.

(See OUTER MARKER.)

b. Middle Compass Locator (LMM)− A compasslocator installed at the site of the middle marker of aninstrument landing system.

(See MIDDLE MARKER.)(See ICAO term LOCATOR.)

COMPASS ROSE− A circle, graduated in degrees,printed on some charts or marked on the ground at anairport. It is used as a reference to either true ormagnetic direction.

COMPLY WITH RESTRICTIONS− An ATCinstruction that requires an aircraft being vectoredback onto an arrival or departure procedure to complywith all altitude and/or speed restrictions depicted onthe procedure. This term may be used in lieu ofrepeating each remaining restriction that appears onthe procedure.

COMPOSITE FLIGHT PLAN− A flight plan whichspecifies VFR operation for one portion of flight andIFR for another portion. It is used primarily inmilitary operations.

(Refer to AIM.)

COMPULSORY REPORTING POINTS− Reportingpoints which must be reported to ATC. They aredesignated on aeronautical charts by solid triangles orfiled in a flight plan as fixes selected to define directroutes. These points are geographical locationswhich are defined by navigation aids/fixes. Pilotsshould discontinue position reporting over compul-sory reporting points when informed by ATC thattheir aircraft is in “radar contact.”

CONDITIONS NOT MONITORED− When anairport operator cannot monitor the condition of themovement area or airfield surface area, thisinformation is issued as a NOTAM. Usuallynecessitated due to staffing, operating hours or othermitigating factors associated with airport operations.

CONFIDENCE MANEUVER− A confidence man-euver consists of one or more turns, a climb ordescent, or other maneuver to determine if the pilotin command (PIC) is able to receive and comply withATC instructions.

CONFLICT ALERT− A function of certain air trafficcontrol automated systems designed to alert radarcontrollers to existing or pending situations betweentracked targets (known IFR or VFR aircraft) thatrequire his/her immediate attention/action.

(See MODE C INTRUDER ALERT.)

CONFLICT RESOLUTION− The resolution ofpotential conflictions between aircraft that are radar



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identified and in communication with ATC byensuring that radar targets do not touch. Pertinenttraffic advisories shall be issued when this procedureis applied.

Note: This procedure shall not be provided utilizingmosaic radar systems.

CONFORMANCE− The condition established whenan aircraft’s actual position is within the conformanceregion constructed around that aircraft at its position,according to the trajectory associated with theaircraft’s Current Plan.

CONFORMANCE REGION− A volume, boundedlaterally, vertically, and longitudinally, within whichan aircraft must be at a given time in order to be inconformance with the Current Plan Trajectory for thataircraft. At a given time, the conformance region isdetermined by the simultaneous application of thelateral, vertical, and longitudinal conformancebounds for the aircraft at the position defined by timeand aircraft’s trajectory.

CONSOLAN− A low frequency, long-distanceNAVAID used principally for transoceanic naviga-tions.

CONTACT−

a. Establish communication with (followed by thename of the facility and, if appropriate, the frequencyto be used).

b. A flight condition wherein the pilot ascertainsthe attitude of his/her aircraft and navigates by visualreference to the surface.

(See CONTACT APPROACH.)(See RADAR CONTACT.)

CONTACT APPROACH− An approach wherein anaircraft on an IFR flight plan, having an air trafficcontrol authorization, operating clear of clouds withat least 1 mile flight visibility and a reasonableexpectation of continuing to the destination airport inthose conditions, may deviate from the instrumentapproach procedure and proceed to the destinationairport by visual reference to the surface. Thisapproach will only be authorized when requested bythe pilot and the reported ground visibility at thedestination airport is at least 1 statute mile.

(Refer to AIM.)

CONTAMINATED RUNWAY− A runway isconsidered contaminated whenever standing water,ice, snow, slush, frost in any form, heavy rubber, or

other substances are present. A runway is contami-nated with respect to rubber deposits or otherfriction-degrading substances when the averagefriction value for any 500-foot segment of the runwaywithin the ALD fails below the recommendedminimum friction level and the average friction valuein the adjacent 500-foot segments falls below themaintenance planning friction level.

CONTERMINOUS U.S.− The 48 adjoining Statesand the District of Columbia.

CONTINENTAL UNITED STATES− The 49 Stateslocated on the continent of North America and theDistrict of Columbia.

CONTINUE− When used as a control instructionshould be followed by another word or wordsclarifying what is expected of the pilot. Example:“continue taxi,” “continue descent,” “continueinbound,” etc.

CONTROL AREA [ICAO]− A controlled airspaceextending upwards from a specified limit above theearth.

CONTROL SECTOR− An airspace area of definedhorizontal and vertical dimensions for which acontroller or group of controllers has air trafficcontrol responsibility, normally within an air routetraffic control center or an approach control facility.Sectors are established based on predominant trafficflows, altitude strata, and controller workload. Pilotcommunications during operations within a sectorare normally maintained on discrete frequenciesassigned to the sector.

(See DISCRETE FREQUENCY.)

CONTROL SLASH− A radar beacon slash repre-senting the actual position of the associated aircraft.Normally, the control slash is the one closest to theinterrogating radar beacon site. When ARTCC radaris operating in narrowband (digitized) mode, thecontrol slash is converted to a target symbol.

CONTROLLED AIRSPACE− An airspace ofdefined dimensions within which air traffic controlservice is provided to IFR flights and to VFR flightsin accordance with the airspace classification.

a. Controlled airspace is a generic term that coversClass A, Class B, Class C, Class D, and Class Eairspace.

b. Controlled airspace is also that airspace withinwhich all aircraft operators are subject to certain pilotqualifications, operating rules, and equipment



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requirements in 14 CFR Part 91 (for specificoperating requirements, please refer to 14 CFRPart 91). For IFR operations in any class of controlledairspace, a pilot must file an IFR flight plan andreceive an appropriate ATC clearance. Each Class B,Class C, and Class D airspace area designated for anairport contains at least one primary airport aroundwhich the airspace is designated (for specificdesignations and descriptions of the airspace classes,please refer to 14 CFR Part 71).

c. Controlled airspace in the United States isdesignated as follows:

1. CLASS A− Generally, that airspace from18,000 feet MSL up to and including FL 600,including the airspace overlying the waters within 12nautical miles of the coast of the 48 contiguous Statesand Alaska. Unless otherwise authorized, all personsmust operate their aircraft under IFR.

2. CLASS B− Generally, that airspace from thesurface to 10,000 feet MSL surrounding the nation’sbusiest airports in terms of airport operations orpassenger enplanements. The configuration of eachClass B airspace area is individually tailored andconsists of a surface area and two or more layers(some Class B airspace areas resemble upside-downwedding cakes), and is designed to contain allpublished instrument procedures once an aircraftenters the airspace. An ATC clearance is required forall aircraft to operate in the area, and all aircraft thatare so cleared receive separation services within theairspace. The cloud clearance requirement for VFRoperations is “clear of clouds.”

3. CLASS C− Generally, that airspace from thesurface to 4,000 feet above the airport elevation(charted in MSL) surrounding those airports thathave an operational control tower, are serviced by aradar approach control, and that have a certainnumber of IFR operations or passenger enplane-ments. Although the configuration of each Class Carea is individually tailored, the airspace usuallyconsists of a surface area with a 5 nautical mile (NM)radius, a circle with a 10NM radius that extends nolower than 1,200 feet up to 4,000 feet above theairport elevation, and an outer area that is not charted.Each person must establish two-way radio commu-nications with the ATC facility providing air trafficservices prior to entering the airspace and thereaftermaintain those communications while within the

airspace. VFR aircraft are only separated from IFRaircraft within the airspace.

(See OUTER AREA.)4. CLASS D− Generally, that airspace from the

surface to 2,500 feet above the airport elevation(charted in MSL) surrounding those airports thathave an operational control tower. The configurationof each Class D airspace area is individually tailoredand when instrument procedures are published, theairspace will normally be designed to contain theprocedures. Arrival extensions for instrumentapproach procedures may be Class D or Class Eairspace. Unless otherwise authorized, each personmust establish two-way radio communications withthe ATC facility providing air traffic services prior toentering the airspace and thereafter maintain thosecommunications while in the airspace. No separationservices are provided to VFR aircraft.

5. CLASS E− Generally, if the airspace is notClass A, Class B, Class C, or Class D, and it iscontrolled airspace, it is Class E airspace. Class Eairspace extends upward from either the surface or adesignated altitude to the overlying or adjacentcontrolled airspace. When designated as a surfacearea, the airspace will be configured to contain allinstrument procedures. Also in this class are Federalairways, airspace beginning at either 700 or 1,200feet AGL used to transition to/from the terminal or enroute environment, en route domestic, and offshoreairspace areas designated below 18,000 feet MSL.Unless designated at a lower altitude, Class Eairspace begins at 14,500 MSL over the UnitedStates, including that airspace overlying the waterswithin 12 nautical miles of the coast of the 48contiguous States and Alaska, up to, but notincluding 18,000 feet MSL, and the airspace aboveFL 600.

CONTROLLED AIRSPACE [ICAO]− An airspaceof defined dimensions within which air traffic controlservice is provided to IFR flights and to VFR flightsin accordance with the airspace classification.

Note: Controlled airspace is a generic term whichcovers ATS airspace Classes A, B, C, D, and E.

CONTROLLED TIME OF ARRIVAL− Arrival timeassigned during a Traffic Management Program. Thistime may be modified due to adjustments or useroptions.

CONTROLLER−(See AIR TRAFFIC CONTROL SPECIALIST.)



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CONTROLLER [ICAO]− A person authorized toprovide air traffic control services.

CONTROLLER PILOT DATA LINKCOMMUNICATIONS (CPDLC)− A two−waydigital communications system that conveys textualair traffic control messages between controllers andpilots using ground or satellite-based radio relaystations.

CONVECTIVE SIGMET− A weather advisoryconcerning convective weather significant to thesafety of all aircraft. Convective SIGMETs are issuedfor tornadoes, lines of thunderstorms, embeddedthunderstorms of any intensity level, areas ofthunderstorms greater than or equal to VIP level 4with an area coverage of 4/10 (40%) or more, and hail3/4 inch or greater.

(See AIRMET.)(See AWW.)(See CWA.)(See SIGMET.)(Refer to AIM.)

CONVECTIVE SIGNIFICANT METEOROLOG-ICAL INFORMATION−

(See CONVECTIVE SIGMET.)

COORDINATES− The intersection of lines ofreference, usually expressed in degrees/minutes/seconds of latitude and longitude, used to determineposition or location.

COORDINATION FIX− The fix in relation to whichfacilities will handoff, transfer control of an aircraft,or coordinate flight progress data. For terminalfacilities, it may also serve as a clearance for arrivingaircraft.

COPTER−(See HELICOPTER.)

CORRECTION− An error has been made in thetransmission and the correct version follows.

COUPLED APPROACH− An instrument approachperformed by the aircraft autopilot, and/or visuallydepicted on the flight director, which is receivingposition information and/or steering commands fromonboard navigational equipment. In general, couplednon-precision approaches must be flown manually(autopilot disengaged) at altitudes lower than 50 feetAGL below the minimum descent altitude, andcoupled precision approaches must be flownmanually (autopilot disengaged) below 50 feet AGL

unless authorized to conduct autoland operations.Coupled instrument approaches are commonly flownto the allowable IFR weather minima established bythe operator or PIC, or flown VFR for training andsafety.

COURSE−

a. The intended direction of flight in the horizontalplane measured in degrees from north.

b. The ILS localizer signal pattern usuallyspecified as the front course or the back course.

(See BEARING.)(See INSTRUMENT LANDING SYSTEM.)(See RADIAL.)

CPDLC−(See CONTROLLER PILOT DATA LINKCOMMUNICATIONS.)

CPL [ICAO]−(See ICAO term CURRENT FLIGHT PLAN.)

CRITICAL ENGINE− The engine which, uponfailure, would most adversely affect the performanceor handling qualities of an aircraft.

CROSS (FIX) AT (ALTITUDE)− Used by ATCwhen a specific altitude restriction at a specified fixis required.

CROSS (FIX) AT OR ABOVE (ALTITUDE)− Usedby ATC when an altitude restriction at a specified fixis required. It does not prohibit the aircraft fromcrossing the fix at a higher altitude than specified;however, the higher altitude may not be one that willviolate a succeeding altitude restriction or altitudeassignment.

(See ALTITUDE RESTRICTION.)(Refer to AIM.)

CROSS (FIX) AT OR BELOW (ALTITUDE)−Used by ATC when a maximum crossing altitude ata specific fix is required. It does not prohibit theaircraft from crossing the fix at a lower altitude;however, it must be at or above the minimum IFRaltitude.

(See ALTITUDE RESTRICTION.)(See MINIMUM IFR ALTITUDES.)(Refer to 14 CFR Part 91.)

CROSSWIND−

a. When used concerning the traffic pattern, theword means “crosswind leg.”

(See TRAFFIC PATTERN.)



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b. When used concerning wind conditions, theword means a wind not parallel to the runway or thepath of an aircraft.

(See CROSSWIND COMPONENT.)

CROSSWIND COMPONENT− The wind compo-nent measured in knots at 90 degrees to thelongitudinal axis of the runway.

CRUISE− Used in an ATC clearance to authorize apilot to conduct flight at any altitude from theminimum IFR altitude up to and including thealtitude specified in the clearance. The pilot maylevel off at any intermediate altitude within this blockof airspace. Climb/descent within the block is to bemade at the discretion of the pilot. However, once thepilot starts descent and verbally reports leaving analtitude in the block, he/she may not return to thataltitude without additional ATC clearance. Further, itis approval for the pilot to proceed to and make anapproach at destination airport and can be used inconjunction with:

a. An airport clearance limit at locations with astandard/special instrument approach procedure. TheCFRs require that if an instrument letdown to anairport is necessary, the pilot shall make the letdownin accordance with a standard/special instrumentapproach procedure for that airport, or

b. An airport clearance limit at locations that arewithin/below/outside controlled airspace and with-out a standard/special instrument approachprocedure. Such a clearance is NOT AUTHORIZA-TION for the pilot to descend under IFR conditionsbelow the applicable minimum IFR altitude nor doesit imply that ATC is exercising control over aircraftin Class G airspace; however, it provides a means forthe aircraft to proceed to destination airport, descend,and land in accordance with applicable CFRsgoverning VFR flight operations. Also, this providessearch and rescue protection until such time as theIFR flight plan is closed.

(See INSTRUMENT APPROACHPROCEDURE.)

CRUISE CLIMB− A climb technique employed byaircraft, usually at a constant power setting, resultingin an increase of altitude as the aircraft weightdecreases.

CRUISING ALTITUDE− An altitude or flight levelmaintained during en route level flight. This is a

constant altitude and should not be confused with acruise clearance.

(See ALTITUDE.)(See ICAO term CRUISING LEVEL.)

CRUISING LEVEL−(See CRUISING ALTITUDE.)

CRUISING LEVEL [ICAO]− A level maintainedduring a significant portion of a flight.

CT MESSAGE− An EDCT time generated by theATCSCC to regulate traffic at arrival airports.Normally, a CT message is automatically transferredfrom the traffic management system computer to theNAS en route computer and appears as an EDCT. Inthe event of a communication failure between thetraffic management system computer and the NAS,the CT message can be manually entered by the TMCat the en route facility.

CTA−(See CONTROLLED TIME OF ARRIVAL.)(See ICAO term CONTROL AREA.)

CTAF−(See COMMON TRAFFIC ADVISORYFREQUENCY.)

CTAS−(See CENTER TRACON AUTOMATIONSYSTEM.)

CTOP−(See COLLABORATIVE TRAJECTORYOPTIONS PROGRAM)

CTRD−(See CERTIFIED TOWER RADAR DISPLAY.)

CURRENT FLIGHT PLAN [ICAO]− The flightplan, including changes, if any, brought about bysubsequent clearances.

CURRENT PLAN− The ATC clearance the aircrafthas received and is expected to fly.

CVFP APPROACH−(See CHARTED VISUAL FLIGHT PROCEDUREAPPROACH.)

CWA−(See CENTER WEATHER ADVISORY andWEATHER ADVISORY.)



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II SAY AGAIN− The message will be repeated.

IAF−(See INITIAL APPROACH FIX.)

IAP−(See INSTRUMENT APPROACHPROCEDURE.)

IAWP− Initial Approach Waypoint

ICAO−(See ICAO Term INTERNATIONAL CIVILAVIATION ORGANIZATION.)

ICAO 3LD−(See ICAO Term ICAO Three−Letter Designator)

ICAO Three−Letter Designator (3LD)− An ICAO3LD is an exclusive designator that, when usedtogether with a flight number, becomes the aircraftcall sign and provides distinct aircraft identificationto air traffic control (ATC). ICAO approves 3LDs toenhance the safety and security of the air trafficsystem. An ICAO 3LD may be assigned to acompany, agency, or organization and is used insteadof the aircraft registration number for ATCoperational and security purposes. An ICAO 3LD isalso used for aircraft identification in the flight planand associated messages and can be used fordomestic and international flights. A telephonyassociated with an ICAO 3LD is used for radiocommunication.

ICING− The accumulation of airframe ice.

Types of icing are:

a. Rime Ice− Rough, milky, opaque ice formed bythe instantaneous freezing of small supercooledwater droplets.

b. Clear Ice− A glossy, clear, or translucent iceformed by the relatively slow freezing or largesupercooled water droplets.

c. Mixed− A mixture of clear ice and rime ice.

Intensity of icing:

a. Trace− Ice becomes perceptible. Rate ofaccumulation is slightly greater than the rate ofsublimation. Deicing/anti-icing equipment is notutilized unless encountered for an extended period oftime (over 1 hour).

b. Light− The rate of accumulation may create aproblem if flight is prolonged in this environment(over 1 hour). Occasional use of deicing/anti-icingequipment removes/prevents accumulation. It doesnot present a problem if the deicing/anti-icingequipment is used.

c. Moderate− The rate of accumulation is such thateven short encounters become potentially hazardousand use of deicing/anti-icing equipment or flightdiversion is necessary.

d. Severe− The rate of ice accumulation is suchthat ice protection systems fail to remove theaccumulation of ice, or ice accumulates in locationsnot normally prone to icing, such as areas aft ofprotected surfaces and any other areas identified bythe manufacturer. Immediate exit from the conditionis necessary.

Note:Severe icing is aircraft dependent, as are the othercategories of icing intensity. Severe icing mayoccur at any ice accumulation rate.

IDENT− A request for a pilot to activate the aircrafttransponder identification feature. This will help thecontroller to confirm an aircraft identity or to identifyan aircraft.

(Refer to AIM.)

IDENT FEATURE− The special feature in the AirTraffic Control Radar Beacon System (ATCRBS)equipment. It is used to immediately distinguish onedisplayed beacon target from other beacon targets.

(See IDENT.)

IDENTIFICATION [ICAO]− The situation whichexists when the position indication of a particularaircraft is seen on a situation display and positivelyidentified.

IF−(See INTERMEDIATE FIX.)

IF NO TRANSMISSION RECEIVED FOR(TIME)− Used by ATC in radar approaches to prefixprocedures which should be followed by the pilot inevent of lost communications.

(See LOST COMMUNICATIONS.)

IFR−(See INSTRUMENT FLIGHT RULES.)



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IFR AIRCRAFT− An aircraft conducting flight inaccordance with instrument flight rules.

IFR CONDITIONS− Weather conditions below theminimum for flight under visual flight rules.

(See INSTRUMENT METEOROLOGICALCONDITIONS.)

IFR DEPARTURE PROCEDURE−(See IFR TAKEOFF MINIMUMS ANDDEPARTURE PROCEDURES.)

(Refer to AIM.)

IFR FLIGHT−(See IFR AIRCRAFT.)

IFR LANDING MINIMUMS−(See LANDING MINIMUMS.)

IFR MILITARY TRAINING ROUTES (IR)− Routesused by the Department of Defense and associatedReserve and Air Guard units for the purpose ofconducting low-altitude navigation and tacticaltraining in both IFR and VFR weather conditionsbelow 10,000 feet MSL at airspeeds in excess of 250knots IAS.

IFR TAKEOFF MINIMUMS AND DEPARTUREPROCEDURES− Title 14 Code of FederalRegulations Part 91, prescribes standard takeoff rulesfor certain civil users. At some airports, obstructionsor other factors require the establishment ofnonstandard takeoff minimums, departure proce-dures, or both to assist pilots in avoiding obstaclesduring climb to the minimum en route altitude. Thoseairports are listed in FAA/DOD Instrument ApproachProcedures (IAPs) Charts under a section entitled“IFR Takeoff Minimums and Departure Procedures.”The FAA/DOD IAP chart legend illustrates thesymbol used to alert the pilot to nonstandard takeoffminimums and departure procedures. When depart-ing IFR from such airports or from any airports wherethere are no departure procedures, DPs, or ATCfacilities available, pilots should advise ATC of anydeparture limitations. Controllers may query a pilotto determine acceptable departure directions, turns,or headings after takeoff. Pilots should be familiarwith the departure procedures and must assure thattheir aircraft can meet or exceed any specified climbgradients.

IF/IAWP− Intermediate Fix/Initial Approach Way-point. The waypoint where the final approach courseof a T approach meets the crossbar of the T. When

designated (in conjunction with a TAA) thiswaypoint will be used as an IAWP when approachingthe airport from certain directions, and as an IFWPwhen beginning the approach from another IAWP.

IFWP− Intermediate Fix Waypoint

ILS−(See INSTRUMENT LANDING SYSTEM.)

ILS CATEGORIES− 1. Category I. An ILS approachprocedure which provides for approach to a heightabove touchdown of not less than 200 feet and withrunway visual range of not less than 1,800 feet.−2. Special Authorization Category I. An ILSapproach procedure which provides for approach toa height above touchdown of not less than 150 feetand with runway visual range of not less than 1,400feet, HUD to DH. 3. Category II. An ILS approachprocedure which provides for approach to a heightabove touchdown of not less than 100 feet and withrunway visual range of not less than 1,200 feet (withautoland or HUD to touchdown and noted onauthorization, RVR 1,000 feet).− 4. SpecialAuthorization Category II with Reduced Lighting.An ILS approach procedure which provides forapproach to a height above touchdown of not lessthan 100 feet and with runway visual range of not lessthan 1,200 feet with autoland or HUD to touchdownand noted on authorization (no touchdown zone andcenterline lighting are required).− 5. Category III:

a. IIIA.−An ILS approach procedure whichprovides for approach without a decision heightminimum and with runway visual range of not lessthan 700 feet.

b. IIIB.−An ILS approach procedure whichprovides for approach without a decision heightminimum and with runway visual range of not lessthan 150 feet.

c. IIIC.−An ILS approach procedure whichprovides for approach without a decision heightminimum and without runway visual rangeminimum.

ILS PRM APPROACH− An instrument landingsystem (ILS) approach conducted to parallel runwayswhose extended centerlines are separated by less than4,300 feet and at least 3,000 feet where independentclosely spaced approaches are permitted. Also usedin conjunction with an LDA PRM, RNAV PRM orGLS PRM approach to conduct Simultaneous OffsetInstrument Approach (SOIA) operations. NoTransgression Zone (NTZ) monitoring is required to



PCG I−3

conduct these approaches. ATC utilizes an enhanceddisplay with alerting and, with certain runwayspacing, a high update rate PRM surveillance sensor.Use of a secondary monitor frequency, pilot PRMtraining, and publication of an Attention All UsersPage are also required for all PRM approaches.

(Refer to AIM)

IM−(See INNER MARKER.)

IMC−(See INSTRUMENT METEOROLOGICALCONDITIONS.)

IMMEDIATELY− Used by ATC or pilots when suchaction compliance is required to avoid an imminentsituation.

INCERFA (Uncertainty Phase) [ICAO]− A situationwherein uncertainty exists as to the safety of anaircraft and its occupants.

INCREASED SEPARATION REQUIRED (ISR)–Indicates the confidence level of the track requires5NM separation. 3NM separation, 1 1/2NMseparation, and target resolution cannot be used.

INCREASE SPEED TO (SPEED)−(See SPEED ADJUSTMENT.)

INERTIAL NAVIGATION SYSTEM (INS)− AnRNAV system which is a form of self-containednavigation.

(See Area Navigation/RNAV.)

INFLIGHT REFUELING−(See AERIAL REFUELING.)

INFLIGHT WEATHER ADVISORY−(See WEATHER ADVISORY.)

INFORMATION REQUEST (INREQ)− A requestoriginated by an FSS for information concerning anoverdue VFR aircraft.

INITIAL APPROACH FIX (IAF)− The fixesdepicted on instrument approach procedure chartsthat identify the beginning of the initial approachsegment(s).

(See FIX.)(See SEGMENTS OF AN INSTRUMENTAPPROACH PROCEDURE.)

INITIAL APPROACH SEGMENT−(See SEGMENTS OF AN INSTRUMENTAPPROACH PROCEDURE.)

INITIAL APPROACH SEGMENT [ICAO]− Thatsegment of an instrument approach procedurebetween the initial approach fix and the intermediateapproach fix or, where applicable, the final approachfix or point.

INLAND NAVIGATION FACILITY− A navigationaid on a North American Route at which the commonroute and/or the noncommon route begins or ends.

INNER MARKER− A marker beacon used with anILS (CAT II) precision approach located between themiddle marker and the end of the ILS runway,transmitting a radiation pattern keyed at six dots persecond and indicating to the pilot, both aurally andvisually, that he/she is at the designated decisionheight (DH), normally 100 feet above the touchdownzone elevation, on the ILS CAT II approach. It alsomarks progress during a CAT III approach.

(See INSTRUMENT LANDING SYSTEM.)(Refer to AIM.)

INNER MARKER BEACON−(See INNER MARKER.)

INREQ−(See INFORMATION REQUEST.)

INS−(See INERTIAL NAVIGATION SYSTEM.)

INSTRUMENT APPROACH−(See INSTRUMENT APPROACHPROCEDURE.)

INSTRUMENT APPROACH OPERATIONS[ICAO]− An approach and landing using instrumentsfor navigation guidance based on an instrumentapproach procedure. There are two methods forexecuting instrument approach operations:

a. A two−dimensional (2D) instrument approachoperation, using lateral navigation guidance only;and

b. A three−dimensional (3D) instrument approachoperation, using both lateral and vertical navigationguidance.

Note: Lateral and vertical navigation guidancerefers to the guidance provided either by:a) a ground−based radio navigation aid; orb) computer−generated navigation data fromground−based, space−based, self−containednavigation aids or a combination of these.

(See ICAO term INSTRUMENT APPROACHPROCEDURE.)

INSTRUMENT APPROACH PROCEDURE− Aseries of predetermined maneuvers for the orderly



PCG I−4

transfer of an aircraft under instrument flightconditions from the beginning of the initial approachto a landing or to a point from which a landing maybe made visually. It is prescribed and approved for aspecific airport by competent authority.

(See SEGMENTS OF AN INSTRUMENTAPPROACH PROCEDURE.)


a. U.S. civil standard instrument approachprocedures are approved by the FAA as prescribedunder 14 CFR Part 97 and are available for publicuse.

b. U.S. military standard instrument approachprocedures are approved and published by theDepartment of Defense.

c. Special instrument approach procedures areapproved by the FAA for individual operators but arenot published in 14 CFR Part 97 for public use.

(See ICAO term INSTRUMENT APPROACHPROCEDURE.)

INSTRUMENT APPROACH PROCEDURE[ICAO]− A series of predetermined maneuvers byreference to flight instruments with specifiedprotection from obstacles from the initial approachfix, or where applicable, from the beginning of adefined arrival route to a point from which a landingcan be completed and thereafter, if a landing is notcompleted, to a position at which holding or en routeobstacle clearance criteria apply.

(See ICAO term INSTRUMENT APPROACHOPERATIONS)

INSTRUMENT APPROACH PROCEDURECHARTS−

(See AERONAUTICAL CHART.)

INSTRUMENT DEPARTURE PROCEDURE(DP)− A preplanned instrument flight rule (IFR)departure procedure published for pilot use, ingraphic or textual format, that provides obstructionclearance from the terminal area to the appropriate enroute structure. There are two types of DP, ObstacleDeparture Procedure (ODP), printed either textuallyor graphically, and, Standard Instrument Departure(SID), which is always printed graphically.

(See IFR TAKEOFF MINIMUMS ANDDEPARTURE PROCEDURES.)

(See OBSTACLE DEPARTURE PROCEDURES.)(See STANDARD INSTRUMENT DEPARTURES.)(Refer to AIM.)

INSTRUMENT DEPARTURE PROCEDURE (DP)CHARTS−

(See AERONAUTICAL CHART.)

INSTRUMENT FLIGHT RULES (IFR)− Rulesgoverning the procedures for conducting instrumentflight. Also a term used by pilots and controllers toindicate type of flight plan.

(See INSTRUMENT METEOROLOGICALCONDITIONS.)

(See VISUAL FLIGHT RULES.)(See VISUAL METEOROLOGICALCONDITIONS.)

(See ICAO term INSTRUMENT FLIGHTRULES.)

(Refer to AIM.)

INSTRUMENT FLIGHT RULES [ICAO]− A set ofrules governing the conduct of flight underinstrument meteorological conditions.

INSTRUMENT LANDING SYSTEM (ILS)− Aprecision instrument approach system which normal-ly consists of the following electronic componentsand visual aids:

a. Localizer.(See LOCALIZER.)

b. Glideslope.(See GLIDESLOPE.)c. Outer Marker.(See OUTER MARKER.)d. Middle Marker.(See MIDDLE MARKER.)

e. Approach Lights.(See AIRPORT LIGHTING.)(Refer to 14 CFR Part 91.)(Refer to AIM.)

INSTRUMENT METEOROLOGICAL CONDI-TIONS (IMC)− Meteorological conditions expressedin terms of visibility, distance from cloud, and ceilingless than the minima specified for visual meteorolog-ical conditions.

(See INSTRUMENT FLIGHT RULES.)(See VISUAL FLIGHT RULES.)(See VISUAL METEOROLOGICALCONDITIONS.)

INSTRUMENT RUNWAY− A runway equippedwith electronic and visual navigation aids for whicha precision or nonprecision approach procedurehaving straight-in landing minimums has beenapproved.

(See ICAO term INSTRUMENT RUNWAY.)



PCG I−5

INSTRUMENT RUNWAY [ICAO]− One of thefollowing types of runways intended for theoperation of aircraft using instrument approachprocedures:

a. Nonprecision Approach Runway− An instru-ment runway served by visual aids and a nonvisualaid providing at least directional guidance adequatefor a straight-in approach.

b. Precision Approach Runway, Category I− Aninstrument runway served by ILS and visual aidsintended for operations down to 60 m (200 feet)decision height and down to an RVR of the order of800 m.

c. Precision Approach Runway, Category II− Aninstrument runway served by ILS and visual aidsintended for operations down to 30 m (100 feet)decision height and down to an RVR of the order of400 m.

d. Precision Approach Runway, Category III− Aninstrument runway served by ILS to and along thesurface of the runway and:

1. Intended for operations down to an RVR ofthe order of 200 m (no decision height beingapplicable) using visual aids during the final phase oflanding;

2. Intended for operations down to an RVR ofthe order of 50 m (no decision height beingapplicable) using visual aids for taxiing;

3. Intended for operations without reliance onvisual reference for landing or taxiing.

Note 1: See Annex 10 Volume I, Part I, Chapter 3,for related ILS specifications.

Note 2: Visual aids need not necessarily bematched to the scale of nonvisual aids provided.The criterion for the selection of visual aids is theconditions in which operations are intended to beconducted.

INTEGRITY− The ability of a system to providetimely warnings to users when the system should notbe used for navigation.

INTERMEDIATE APPROACH SEGMENT−(See SEGMENTS OF AN INSTRUMENTAPPROACH PROCEDURE.)

INTERMEDIATE APPROACH SEGMENT[ICAO]− That segment of an instrument approachprocedure between either the intermediate approachfix and the final approach fix or point, or between theend of a reversal, race track or dead reckoning track

procedure and the final approach fix or point, asappropriate.

INTERMEDIATE FIX− The fix that identifies thebeginning of the intermediate approach segment of aninstrument approach procedure. The fix is notnormally identified on the instrument approach chartas an intermediate fix (IF).

(See SEGMENTS OF AN INSTRUMENTAPPROACH PROCEDURE.)

INTERMEDIATE LANDING− On the rare occasionthat this option is requested, it should be approved.The departure center, however, must advise theATCSCC so that the appropriate delay is carried overand assigned at the intermediate airport. Anintermediate landing airport within the arrival centerwill not be accepted without coordination with andthe approval of the ATCSCC.

INTERNATIONAL AIRPORT− Relating to interna-tional flight, it means:

a. An airport of entry which has been designatedby the Secretary of Treasury or Commissioner ofCustoms as an international airport for customsservice.

b. A landing rights airport at which specificpermission to land must be obtained from customsauthorities in advance of contemplated use.

c. Airports designated under the Convention onInternational Civil Aviation as an airport for use byinternational commercial air transport and/or interna-tional general aviation.

(See ICAO term INTERNATIONAL AIRPORT.)(Refer to Chart Supplement U.S.)

INTERNATIONAL AIRPORT [ICAO]− Any airportdesignated by the Contracting State in whoseterritory it is situated as an airport of entry anddeparture for international air traffic, where theformalities incident to customs, immigration, publichealth, animal and plant quarantine and similarprocedures are carried out.

INTERNATIONAL CIVIL AVIATION ORGA-NIZATION [ICAO]− A specialized agency of theUnited Nations whose objective is to develop theprinciples and techniques of international airnavigation and to foster planning and development ofinternational civil air transport.

INTERROGATOR− The ground-based surveillanceradar beacon transmitter-receiver, which normallyscans in synchronism with a primary radar,



PCG I−6

transmitting discrete radio signals which repetitious-ly request all transponders on the mode being used toreply. The replies received are mixed with theprimary radar returns and displayed on the same planposition indicator (radar scope). Also, applied to theairborne element of the TACAN/DME system.

(See TRANSPONDER.)(Refer to AIM.)

INTERSECTING RUNWAYS− Two or morerunways which cross or meet within their lengths.

(See INTERSECTION.)

INTERSECTION−

a. A point defined by any combination of courses,radials, or bearings of two or more navigational aids.

b. Used to describe the point where two runways,a runway and a taxiway, or two taxiways cross ormeet.

INTERSECTION DEPARTURE− A departure fromany runway intersection except the end of the runway.

(See INTERSECTION.)

INTERSECTION TAKEOFF−(See INTERSECTION DEPARTURE.)

IR−(See IFR MILITARY TRAINING ROUTES.)

IRREGULAR SURFACE− A surface that is open foruse but not per regulations.

ISR−(See INCREASED SEPARATION REQUIRED.)



PCG N−3

a. Nonradar Approach. Used to describeinstrument approaches for which course guidance onfinal approach is not provided by ground-basedprecision or surveillance radar. Radar vectors to thefinal approach course may or may not be provided byATC. Examples of nonradar approaches are VOR,NDB, TACAN, ILS, RNAV, and GLS approaches.

(See FINAL APPROACH COURSE.)(See FINAL APPROACH-IFR.)(See INSTRUMENT APPROACHPROCEDURE.)

(See RADAR APPROACH.)

b. Nonradar Approach Control. An ATC facilityproviding approach control service without the use ofradar.

(See APPROACH CONTROL FACILITY.)(See APPROACH CONTROL SERVICE.)

c. Nonradar Arrival. An aircraft arriving at anairport without radar service or at an airport served bya radar facility and radar contact has not beenestablished or has been terminated due to a lack ofradar service to the airport.

(See RADAR ARRIVAL.)(See RADAR SERVICE.)

d. Nonradar Route. A flight path or route overwhich the pilot is performing his/her own navigation.The pilot may be receiving radar separation, radarmonitoring, or other ATC services while on anonradar route.

(See RADAR ROUTE.)

e. Nonradar Separation. The spacing of aircraft inaccordance with established minima without the useof radar; e.g., vertical, lateral, or longitudinalseparation.

(See RADAR SEPARATION.)

NON−RESTRICTIVE ROUTING (NRR)− Portionsof a proposed route of flight where a user can flightplan the most advantageous flight path with norequirement to make reference to ground−basedNAVAIDs.

NOPAC−(See NORTH PACIFIC.)

NORDO (No Radio)− Aircraft that cannot or do notcommunicate by radio when radio communication isrequired are referred to as “NORDO.”

(See LOST COMMUNICATIONS.)

NORMAL OPERATING ZONE (NOZ)− The NOZis the operating zone within which aircraft flightremains during normal independent simultaneousparallel ILS approaches.

NORTH AMERICAN ROUTE− A numericallycoded route preplanned over existing airway androute systems to and from specific coastal fixesserving the North Atlantic. North American Routesconsist of the following:

a. Common Route/Portion. That segment of aNorth American Route between the inland navigationfacility and the coastal fix.

b. Noncommon Route/Portion. That segment of aNorth American Route between the inland navigationfacility and a designated North American terminal.

c. Inland Navigation Facility. A navigation aid ona North American Route at which the common routeand/or the noncommon route begins or ends.

d. Coastal Fix. A navigation aid or intersectionwhere an aircraft transitions between the domesticroute structure and the oceanic route structure.

NORTH AMERICAN ROUTE PROGRAM (NRP)−The NRP is a set of rules and procedures which aredesigned to increase the flexibility of user flightplanning within published guidelines.

NORTH ATLANTIC HIGH LEVEL AIRSPACE(NAT HLA)− That volume of airspace (as defined inICAO Document 7030) between FL 285 and FL 420within the Oceanic Control Areas of Bodo Oceanic,Gander Oceanic, New York Oceanic East, Reykjavik,Santa Maria, and Shanwick, excluding the Shannonand Brest Ocean Transition Areas. ICAO Doc 007North Atlantic Operations and Airspace Manualprovides detailed information on related aircraft andoperational requirements.

NORTH MARK− A beacon data block sent by thehost computer to be displayed by the ARTS on a 360degree bearing at a locally selected radar azimuth anddistance. The North Mark is used to ensure correctrange/azimuth orientation during periods ofCENRAP.

NORTH PACIFIC− An organized route systembetween the Alaskan west coast and Japan.

NOT STANDARD− Varying from what is expectedor published. For use in NOTAMs only.

NOT STD-

(See NOT STANDARD.)



PCG N−4

NOTAM−(See NOTICE TO AIRMEN.)

NOTAM [ICAO]− A notice containing informationconcerning the establishment, condition or change inany aeronautical facility, service, procedure orhazard, the timely knowledge of which is essential topersonnel concerned with flight operations.

a. I Distribution− Distribution by means oftelecommunication.

b. II Distribution− Distribution by means otherthan telecommunications.

NOTICE TO AIRMEN (NOTAM)− A noticecontaining information (not known sufficiently inadvance to publicize by other means) concerning theestablishment, condition, or change in anycomponent (facility, service, or procedure of, orhazard in the National Airspace System) the timelyknowledge of which is essential to personnelconcerned with flight operations.

NOTAM(D)− A NOTAM given (in addition to localdissemination) distant dissemination beyond the areaof responsibility of the Flight Service Station. TheseNOTAMs will be stored and available until canceled.

c. FDC NOTAM− A NOTAM regulatory innature, transmitted by USNOF and given systemwide dissemination.

(See ICAO term NOTAM.)

NOTICES TO AIRMEN PUBLICATION− Apublication issued every 28 days, designed primarilyfor the pilot, which contains NOTAMs, graphicnotices, and other information considered essential tothe safety of flight as well as supplemental data toother aeronautical publications. The contractionNTAP is used in NOTAM text.

(See NOTICE TO AIRMEN.)

NRR−(See NON−RESTRICTIVE ROUTING.)

NRS−(See NAVIGATION REFERENCE SYSTEM.)

NTAP−(See NOTICES TO AIRMEN PUBLICATION.)

NUMEROUS TARGETS VICINITY (LOCA-TION)− A traffic advisory issued by ATC to advisepilots that targets on the radar scope are too numerousto issue individually.

(See TRAFFIC ADVISORIES.)



PCG U−1

UUHF−

(See ULTRAHIGH FREQUENCY.)

ULTRAHIGH FREQUENCY (UHF)− The frequen-cy band between 300 and 3,000 MHz. The bank ofradio frequencies used for military air/ground voicecommunications. In some instances this may go aslow as 225 MHz and still be referred to as UHF.

ULTRALIGHT VEHICLE− A single-occupantaeronautical vehicle operated for sport or recreationalpurposes which does not require FAA registration, anairworthiness certificate, or pilot certification.Operation of an ultralight vehicle in certain airspacerequires authorization from ATC.


UNABLE− Indicates inability to comply with aspecific instruction, request, or clearance.

UNASSOCIATED− A radar target that does notdisplay a data block with flight identification andaltitude information.

(See ASSOCIATED.)

UNCONTROLLED AIRSPACE− Airspace in whichaircraft are not subject to controlled airspace (ClassA, B, C, D, or E) separation criteria.

UNDER THE HOOD− Indicates that the pilot isusing a hood to restrict visibility outside the cockpitwhile simulating instrument flight. An appropriatelyrated pilot is required in the other control seat whilethis operation is being conducted.


UNFROZEN− The Scheduled Time of Arrival (STA)tags, which are still being rescheduled by the timebased flow management (TBFM) calculations. Theaircraft will remain unfrozen until the time thecorresponding estimated time of arrival (ETA) tagpasses the preset freeze horizon for that aircraft’sstream class. At this point the automatic reschedulingwill stop, and the STA becomes “frozen.”

UNICOM− A nongovernment communication facil-ity which may provide airport information at certainairports. Locations and frequencies of UNICOMs areshown on aeronautical charts and publications.

(See CHART SUPPLEMENT U.S.)(Refer to AIM.)

UNMANNED AIRCRAFT (UA)- A device used orintended to be used for flight that has no onboardpilot. This device can be any type of airplane,helicopter, airship, or powered-lift aircraft.Unmanned free balloons, moored balloons, tetheredaircraft, gliders, and unmanned rockets are notconsidered to be a UA.

UNMANNED AIRCRAFT SYSTEM (UAS)- Anunmanned aircraft and its associated elements relatedto safe operations, which may include controlstations (ground, ship, or air based), control links,support equipment, payloads, flight terminationsystems, and launch/recovery equipment. It consistsof three elements: unmanned aircraft, control station,and data link.

UNPUBLISHED ROUTE− A route for which nominimum altitude is published or charted for pilotuse. It may include a direct route between NAVAIDs,a radial, a radar vector, or a final approach coursebeyond the segments of an instrument approachprocedure.

(See PUBLISHED ROUTE.)(See ROUTE.)

UNRELIABLE (GPS/WAAS)− An advisory topilots indicating the expected level of service of theGPS and/or WAAS may not be available. Pilots mustthen determine the adequacy of the signal for desireduse.

UPWIND LEG−(See TRAFFIC PATTERN.)

URGENCY− A condition of being concerned aboutsafety and of requiring timely but not immediateassistance; a potential distress condition.

(See ICAO term URGENCY.)

URGENCY [ICAO]− A condition concerning thesafety of an aircraft or other vehicle, or of person onboard or in sight, but which does not requireimmediate assistance.

USAFIB−(See ARMY AVIATION FLIGHT INFORMATIONBULLETIN.)


Documents

2/28/19 Pilot/Controller Glossary PILOT/CONTROLLER GLOSSARY · Pilot/Controller Glossary 3/29/18 PCG C−4 CLEARED THROUGH− ATC authorization for an aircraft to make intermediate