Aeronautical Information Manual (AIM), page 181

Index   180 -- Page 181 -- 182


numbers" in communications with the FSS. Use of
this phrase means that the pilot has received wind,
runway, and altimeter information ONLY and the
Alaska FSS does not have to repeat this information.
It does not indicate receipt of the AFIS broadcast and
should never be used for this purpose.

4-1-15. Radar Traffic Information Service

This is a service provided by radar ATC facilities.
Pilots receiving this service are advised of any radar
target observed on the radar display which may be in

such proximity to the position of their aircraft or its

intended route of flight that it warrants their attention.
This service is not intended to relieve the pilot of the
responsibility for continual vigilance to see and avoid
other aircraft.

a. Purpose of the Service

1. The issuance of traffic information as
observed on a radar display is based on the principle
of assisting and advising a pilot that a particular radar
target's position and track indicates it may intersect or
pass in such proximity to that pilot's intended flight
path that it warrants attention. This is to alert the pilot
to the traffic, to be on the lookout for it, and thereby
be in a better position to take appropriate action
should the need arise.
2. Pilots are reminded that the surveillance radar
used by ATC does not provide altitude information
unless the aircraft is equipped with Mode C and the
radar facility is capable of displaying altitude
b. Provisions of the Service

1. Many factors, such as limitations of the radar,
volume of traffic, controller workload and commu-
nications frequency congestion, could prevent the
controller from providing this service. Controllers
possess complete discretion for determining whether
they are able to provide or continue to provide this
service in a specific case. The controller's reason
against providing or continuing to provide the service
in a particular case is not subject to question nor need
it be communicated to the pilot. In other words, the
provision of this service is entirely dependent upon
whether controllers believe they are in a position to
provide it. Traffic information is routinely provided
to all aircraft operating on IFR flight plans except
when the pilot declines the service, or the pilot is
operating within Class A airspace. Traffic informa-

tion may be provided to flights not operating on IFR
flight plans when requested by pilots of such flights.
Radar ATC facilities normally display and monitor both
primary and secondary radar when it is available, except
that secondary radar may be used as the sole display
source in Class A airspace, and under some circumstances
outside of Class A airspace (beyond primary coverage and

in en route areas where only secondary is available).
Secondary radar may also be used outside Class A
airspace as the sole display source when the primary radar
is temporarily unusable or out of service. Pilots in contact
with the affected ATC facility are normally advised when

a temporary outage occurs; i.e., "primary radar out of
service; traffic advisories available on transponder
aircraft only." This means simply that only the aircraft
which have transponders installed and in use will be
depicted on ATC radar indicators when the primary radar
is temporarily out of service.

2. When receiving VFR radar advisory service,
pilots should monitor the assigned frequency at all
times. This is to preclude controllers' concern for
radio failure or emergency assistance to aircraft under
the controller's jurisdiction. VFR radar advisory
service does not include vectors away from
conflicting traffic unless requested by the pilot. When
advisory service is no longer desired, advise the
controller before changing frequencies and then
change your transponder code to 1200, if applicable.
Pilots should also inform the controller when
changing VFR cruising altitude. Except in programs
where radar service is automatically terminated, the
controller will advise the aircraft when radar is
Participation by VFR pilots in formal programs
implemented at certain terminal locations constitutes pilot
request. This also applies to participating pilots at those
locations where arriving VFR flights are encouraged to
make their first contact with the tower on the approach
control frequency.
c. Issuance of Traffic Information. Traffic
information will include the following concerning a
target which may constitute traffic for an aircraft that
1. Radar identified

(a) Azimuth from the aircraft in terms of the
12 hour clock, or
(b) When rapidly maneuvering civil test or
military aircraft prevent accurate issuance of traffic
as in (a) above, specify the direction from an aircraft's

Services Available to Pilots 4-1-9

Page 181 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   180 -- Page 181 -- 182