Order 7110.65P, Air Traffic Control, with changes

Pilot/Controller Glossary 8/5/04ALTERNATE AIRPORT− An airport at which anaircraft may land if a landing at the intended airportbecomes inadvisable.(See ICAO term ALTERNATE AERODROME.)ALTIMETER SETTING− The barometric pressurereading used to adjust a pressure altimeter forvariations in existing atmospheric pressure or to thestandard altimeter setting (29.92).(Refer to 14 CFR Part 91.)(Refer to AIM.)ALTITUDE− The height of a level, point, or objectmeasured in feet Above Ground Level (AGL) or fromMean Sea Level (MSL).(See FLIGHT LEVEL.)a. MSL Altitude− Altitude expressed in feetmeasured from mean sea level.b. AGL Altitude− Altitude expressed in feetmeasured above ground level.c. Indicated Altitude− The altitude as shown by analtimeter. On a pressure or barometric altimeter it isaltitude as shown uncorrected for instrument errorand uncompensated for variation from standardatmospheric conditions.(See ICAO term ALTITUDE.)ALTITUDE [ICAO]− The vertical distance of a level,a point or an object considered as a point, measuredfrom mean sea level (MSL).ALTITUDE READOUT− An aircraft’s altitude,transmitted via the Mode C transponder feature, thatis visually displayed in 100-foot increments on aradar scope having readout capability.(See ALPHANUMERIC DISPLAY.)(See AUTOMATED RADAR TERMINALSYSTEMS.)(See NAS STAGE A.)(Refer to AIM.)ALTITUDE RESERVATION− Airspace utilizationunder prescribed conditions normally employed forthe mass movement of aircraft or other special userrequirements which cannot otherwise beaccomplished. ALTRVs are approved by the appropriateFAA facility.(See AIR TRAFFIC CONTROL SYSTEMCOMMAND CENTER.)ALTITUDE RESTRICTION− An altitude or altitudes,stated in the order flown, which are to bemaintained until reaching a specific point or time.Altitude restrictions may be issued by ATC due totraffic, terrain, or other airspace considerations.ALTITUDE RESTRICTIONS ARE CANCELED−Adherence to previously imposed altitude restrictionsis no longer required during a climb or descent.ALTRV−(See ALTITUDE RESERVATION.)AMASS−(See AIRPORT MOVEMENT AREA SAFETYSYSTEM.)AMVER−(See AUTOMATED MUTUAL-ASSISTANCEVESSEL RESCUE SYSTEM.)APB−(See AUTOMATED PROBLEM DETECTIONBOUNDARY.)APD−(See AUTOMATED PROBLEM DETECTION.)APDIA−(See AUTOMATED PROBLEM DETECTIONINHIBITED AREA.)APPROACH CLEARANCE− Authorization byATC for a pilot to conduct an instrument approach.The type of instrument approach for which aclearance and other pertinent information is providedin the approach clearance when required.(See CLEARED APPROACH.)(See INSTRUMENT APPROACHPROCEDURE.)(Refer to AIM.)(Refer to 14 CFR Part 91.)APPROACH CONTROL FACILITY− A terminalATC facility that provides approach control service ina terminal area.(See APPROACH CONTROL SERVICE.)(See RADAR APPROACH CONTROLFACILITY.)APPROACH CONTROL SERVICE− Air trafficcontrol service provided by an approach controlfacility for arriving and departing VFR/IFR aircraftand, on occasion, en route aircraft. At some airportsnot served by an approach control facility, theARTCC provides limited approach control service.(See ICAO term APPROACH CONTROLSERVICE.)(Refer to AIM.)APPROACH CONTROL SERVICE [ICAO]− Airtraffic control service for arriving or departingcontrolled flights.PCG A−10