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Pilot/Controller Glossary 

ATC CLEARANCE

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(See AIR TRAFFIC CLEARANCE.) 

ATC CLEARS

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 Used to prefix an ATC clearance when it is relayed to an aircraft by other than an air traffic 

controller. 
ATC INSTRUCTIONS

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Directives issued by air traffic control for the purpose of requiring a pilot to take 

specific actions; e.g., “Turn left heading two five zero,” “Go around,” “Clear the runway.” 

(Refer to 14 CFR Part 91.) 

ATC PREFERRED ROUTE NOTIFICATION

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 EDST notification to the appropriate controller of the need to 

determine if an ATC preferred route needs to be applied, based on destination airport. 

(See ROUTE ACTION NOTIFICATION.) 
(See EN ROUTE DECISION SUPPORT TOOL.) 

ATC PREFERRED ROUTES

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 Preferred routes that are not automatically applied by Host. 

ATC REQUESTS

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Used to prefix an ATC request when it is relayed to an aircraft by other than an air traffic 

controller. 
ATC SECURITY SERVICES

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 Communications and security tracking provided by an ATC facility in support 

of the DHS, the DoD, or other Federal security elements in the interest of national security. Such security services 

are only applicable within designated areas. ATC security services do not include ATC basic radar services or 

flight following. 
ATC SECURITY SERVICES POSITION

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 The position responsible for providing ATC security services as 

defined. This position does not provide ATC, IFR separation, or VFR flight following services, but is responsible 

for providing security services in an area comprising airspace assigned to one or more ATC operating sectors. 

This position may be combined with control positions. 
ATC SECURITY TRACKING

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 The continuous tracking of aircraft movement by an ATC facility in support 

of the DHS, the DoD, or other security elements for national security using radar (i.e., radar tracking) or other 

means (e.g., manual tracking) without providing basic radar services (including traffic advisories) or other ATC 

services not defined in this section. 
ATS SURVEILLANCE SERVICE [ICAO]– A term used to indicate a service provided directly by means of an 

ATS surveillance system. 
ATC SURVEILLANCE SOURCE– Used by ATC for establishing identification, control and separation using 

a target depicted on an air traffic control facility’s video display that has met the relevant safety standards for 

operational use and received from one, or a combination, of the following surveillance sources: 

a. 

Radar (See RADAR.) 

b. 

ADS-B (See AUTOMATIC DEPENDENT SURVEILLANCE

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BROADCAST.) 

c. 

WAM (See WIDE AREA MULTILATERATION.) 

(See INTERROGATOR.) 
(See TRANSPONDER.) 
(See ICAO term RADAR.) 
(Refer to AIM.) 

ATS SURVEILLANCE SYSTEM [ICAO]– A generic term meaning variously, ADS

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B, PSR, SSR or any 

comparable ground

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based system that enables the identification of aircraft. 

Note: A comparable ground

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based system is one that has been demonstrated, by comparative assessment 

or other methodology, to have a level of safety and performance equal to or better than monopulse SSR. 

ATCAA

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(See ATC ASSIGNED AIRSPACE.) 

ATCRBS

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(See RADAR.) 

PCG A

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