background image

AIM 

6/17/21 

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: 

PHRASEOLOGY

 

YOUR ADS

B TRANSMITTER APPEARS TO BE 

INOPERATIVE/MALFUNCTIONING. STOP ADS

TRANSMISSIONS. 

(b) 

ATC will inform the flight crew if it 

becomes necessary to turn off the aircraft’s ADS

transmitter. 

PHRASEOLOGY

 

STOP ADS

B TRANSMISSIONS. 

(c) 

Other malfunctions and considerations: 

Loss of automatic altitude reporting capabilities 
(encoder failure) will result in loss of ATC altitude 
advisory services. 

4. 

Procedures for Accommodation of Non

 

ADS

B Equipped Aircraft: 

(a) 

Pilots of aircraft not equipped with 

ADS

B may only operate outside airspace designat-

ed as ADS

B airspace in 14 CFR §91.225. Pilots of 

unequipped aircraft wishing to fly any portion of a 
flight in ADS

B airspace may seek a deviation from 

the regulation to conduct operations without the 
required equipment. Direction for obtaining this 
deviation are available in Advisory Circular 90

114. 

(b) 

While air traffic controllers can identify 

which aircraft are ADS

B equipped and which are 

not, there is no indication if a non

equipped pilot has 

obtained a preflight authorization to enter ADS

airspace. Situations may occur when the pilot of a 
non

equipped  aircraft, without an authorization to 

operate in ADS

B airspace receives an ATC

initiat-

ed in

flight clearance to fly a heading, route, or 

altitude that would penetrate ADS

B airspace. Such 

clearances may be for traffic, weather, or simply to 
shorten the aircraft’s route of flight. When this 
occurs, the pilot should acknowledge and execute the 
clearance, but must advise the controller that they are 
not ADS

B equipped and have not received prior 

authorization to operate in ADS

B airspace. The 

controller, at their discretion, will either acknowledge 
and proceed with the new clearance, or modify the 
clearance to avoid ADS

B airspace. In either case, 

the FAA will normally not take enforcement action 
for non

equipage in these circumstances. 

NOTE

 

Pilots operating without ADS

B equipment must not 

request route or altitude changes that will result in an 
incursion into ADS

B airspace except for safety of flight; 

for example, weather avoidance. Unequipped aircraft that 
have not received a pre

flight deviation authorization will 

only be considered in compliance with regulation if the 
amendment to flight is initiated by ATC. 

EXAMPLE

 

1. 

ATC:

 “November Two Three Quebec, turn fifteen 

degrees left, proceed direct Bradford when able, rest of 
route unchanged.” 

Aircraft:

 “November Two Three Quebec, turning fifteen 

degrees left, direct Bradford when able, rest of route 
unchanged. Be advised, we are negative ADS

B equipment 

and have not received authorization to operate in ADS

airspace.” 

ATC

: “November Two Three Quebec, roger” 

or 
“November Two Three Quebec, roger, turn twenty degrees 
right, rejoin Victor Ten, rest of route unchanged.” 

2. 

ATC:

 “November Four Alpha Tango, climb and 

maintain one zero thousand for traffic.” 

Aircraft:

 “November Four Alpha Tango, leaving eight 

thousand for one zero thousand. Be advised, we are 
negative ADS

B equipment and have not received 

authorization to operate in ADS

B airspace.” 

ATC:

 “November Four Alpha Tango, roger” 

or 
“November Four Alpha Tango, roger, cancel climb 
clearance, maintain eight thousand.” 

REFERENCE

 

Federal Register Notice, Volume 84, Number 62, dated April 1, 2019 

e.  ADS

B Limitations. 

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 or 
authorized, as a direct result of an ADS

B target 

being displayed in the cockpit. 

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

4

5

18 

Surveillance Systems