AIM 

4/20/23 

of air

−

to

−

air ADS

−

B are for “advisory” use only, enhancing a pilot’s visual acquisition of other nearby equipped 

aircraft either when airborne or on the airport surface. Additionally, ADS

−

B will enable ATC and fleet operators 

to monitor aircraft throughout the available ground station coverage area. 

FIG 4

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5

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9 

En Route 

−

 ADS

−

B/ADS

−

R/TIS

−

B/FIS

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B Service Ceilings/Floors 

FIG 4

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5

−

10 

Terminal 

−

 ADS

−

B/ADS

−

R/TIS

−

B/FIS

−

B Service Ceilings/Floors 

2. 

One of the data elements transmitted by ADS

−

B is the aircraft’s Flight Identification (FLT ID). The FLT 

ID is comprised of a maximum of seven alphanumeric characters and must correspond to the aircraft 

identification filed in the flight plan. For airline and commuter aircraft, the FLT ID is usually the company name 

and flight number (for example, AAL3432), and is typically entered into the avionics by the flight crew during 

preflight. For general aviation (GA), if aircraft avionics allow dynamic modification of the FLT ID, the pilot can 

4

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5

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20 

Surveillance Systems