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Surveillance Systems

3. Aircraft with an Inoperative/Malfunctioning

ADS−B Transmitter:

(a) ATC will inform the flight crew when the

aircraft’s ADS−B transmitter appears to be inopera-

tive or malfunctioning:





(b) ATC will inform the flight crew if it

becomes necessary to turn off the aircraft’s ADS−B




(c) Other malfunctions and considerations:

Loss of automatic altitude reporting capabilities

(encoder failure) will result in loss of ATC altitude

advisory services.

e. ADS−B Limitations.

1. The ADS−B cockpit display of traffic is NOT

intended to be used as a collision avoidance system

and does not relieve the pilot’s responsibility to “see

and avoid” other aircraft. (See paragraph 5−5−8, See

and Avoid). ADS−B must not be used for avoidance

maneuvers during IMC or other times when there is

no visual contact with the intruder aircraft. ADS−B is

intended only to assist in visual acquisition of other

aircraft. No avoidance maneuvers are provided nor

authorized, as a direct result of an ADS−B target

being displayed in the cockpit.

2. Use of ADS−B radar services is limited to the

service volume of the GBT.


The coverage volume of GBTs are limited to line−of−sight.

f. Reports of ADS−B Malfunctions.

Users of ADS−B can provide valuable assistance in

the correction of malfunctions by reporting instances

of undesirable system performance. Since ADS-B

performance is monitored by maintenance personnel

rather than ATC, report malfunctions to the nearest

Flight Service Station (FSS) facility by radio or

telephone. Reporters should identify:

1. Condition observed.
2. Date and time of observation.
3. Altitude and location of observation.

4. Type and call sign of the aircraft.
5. Type and software version of avionics


4−5−8. Traffic Information Service−

Broadcast (TIS−B)

a. Introduction

TIS−B is the broadcast of ATC derived traffic

information to ADS−B equipped (1090ES or UAT)

aircraft from ground radio stations. The source of this

traffic information is derived from ground−based air

traffic surveillance sensors. TIS−B service will be

available throughout the NAS where there are both

adequate surveillance coverage from ground sensors

and adequate broadcast coverage from ADS−B

ground radio stations. The quality level of traffic

information provided by TIS−B is dependent upon

the number and type of ground sensors available as

TIS−B sources and the timeliness of the reported

data. (See FIG 4−5−8 and FIG 4−5−9.)

b. TIS−B Requirements.

In order to receive TIS−B service, the following

conditions must exist:

1. Aircraft must be equipped with an ADS−B

transmitter/receiver or transceiver, and a cockpit

display of traffic information (CDTI).

2. Aircraft must fly within the coverage volume

of a compatible ground radio station that is

configured for TIS−B uplinks. (Not all ground radio

stations provide TIS−B due to a lack of radar

coverage or because a radar feed is not available).

3. Aircraft must be within the coverage of and

detected by at least one ATC radar serving the ground

radio station in use.

c. TIS−B Capabilities.

1. TIS−B is intended to provide ADS−B

equipped aircraft with a more complete traffic picture

in situations where not all nearby aircraft are

equipped with ADS−B Out. This advisory−only

application is intended to enhance a pilot’s visual

acquisition of other traffic.

2. Only transponder−equipped targets

(i.e., Mode A/C or Mode S transponders) are

transmitted through the ATC ground system

architecture. Current radar siting may result in

limited radar surveillance coverage at lower