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AIM 

6/17/21 

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 
is: 

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 
position in terms of the eight cardinal compass points 
(N, NE, E, SE, S, SW, W, NW). This method must be 
terminated at the pilot’s request. 

(c) 

Distance from the aircraft in nautical 

miles; 

(d) 

Direction in which the target is proceed-

ing; and 

(e) 

Type of aircraft and altitude if known. 

EXAMPLE

 

Traffic 10 o’clock, 3 miles, west-bound (type aircraft and 
altitude, if known, of the observed traffic). The altitude may 
be known, by means of Mode C, but not verified with the 
pilot for accuracy. (To be valid for separation purposes by 
ATC, the accuracy of Mode C readouts must be verified. 
This is usually accomplished upon initial entry into the 
radar system by a comparison of the readout to pilot stated 
altitude, or the field elevation in the case of continuous 
readout being received from an aircraft on the airport.) 
When necessary to issue traffic advisories containing 
unverified altitude information, the controller will issue the 
indicated altitude of the aircraft. The pilot may upon 
receipt of traffic information, request a vector (heading) to 
avoid such traffic. The vector will be provided to the extent 
possible as determined by the controller provided the 
aircraft to be vectored is within the airspace under the 
jurisdiction of the controller. 

2.  Not radar identified 

(a) 

Distance and direction with respect to a 

fix; 

(b) 

Direction in which the target is proceed-

ing; and 

(c) 

Type of aircraft and altitude if known. 

EXAMPLE

 

Traffic 8 miles south of the airport northeast

bound, (type 

aircraft and altitude if known). 

d. 

The examples depicted in the following figures 

point out the possible error in the position of this 
traffic when it is necessary for a pilot to apply drift 
correction to maintain this track. This error could also 
occur in the event a change in course is made at the 
time radar traffic information is issued. 

FIG 4

1

Induced Error in Position of Traffic 

WIND

 

TRACK

 

TRACK

 

(A)

 

(B)

 

EXAMPLE

 

In FIG 4

1

1 traffic information would be issued to the 

pilot of aircraft “A” as 12 o’clock. The actual position of 
the traffic as seen by the pilot of aircraft “A” would be 
2 o’clock. Traffic information issued to aircraft “B” would 
also be given as 12 o’clock, but in this case, the pilot of “B” 
would see the traffic at 10 o’clock. 

FIG 4

1

Induced Error in Position of Traffic 

TRACK

 

(C)

 

(D)

 

WIND

 

TRACK

 

EXAMPLE

 

In FIG 4

1

2 traffic information would be issued to the 

pilot of aircraft “C” as 2 o’clock. The actual position of the 
traffic as seen by the pilot of aircraft “C” would be 
3 o’clock. Traffic information issued to aircraft “D” would 
be at an 11 o’clock position. Since it is not necessary for the 
pilot of aircraft “D” to apply wind correction (crab) to 
remain on track, the actual position of the traffic issued 
would be correct. Since the radar controller can only 
observe aircraft track (course) on the radar display, traffic 
advisories are issued accordingly, and pilots should give 
due consideration to this fact when looking for reported 
traffic. 

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16.  Safety Alert 

A safety alert will be issued to pilots of aircraft being 
controlled by ATC if the controller is aware the 
aircraft is at an altitude which, in the controller’s 

Services Available to Pilots 

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