4/20/23 

AIM 

(c) 

Type of aircraft and altitude if known. 

EXAMPLE

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Traffic 8 miles south of the airport northeast

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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

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1

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1 

Induced Error in Position of Traffic 

WIND 

TRACK 

TRACK 

(A) 

(B) 

EXAMPLE

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In FIG 4

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1

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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

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1

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2 

Induced Error in Position of Traffic 

TRACK 

(C) 

(D) 

WIND 

TRACK 

EXAMPLE

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In FIG 4

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1

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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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1

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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 judgment, places the aircraft in unsafe proximity to terrain, obstructions 

or other aircraft. The provision of this service is contingent upon the capability of the controller to have an 

awareness of a situation involving unsafe proximity to terrain, obstructions and uncontrolled aircraft. The 

issuance of a safety alert cannot be mandated, but it can be expected on a reasonable, though intermittent basis. 

Once the alert is issued, it is solely the pilot’s prerogative to determine what course of action, if any, to take. This 

procedure is intended for use in time critical situations where aircraft safety is in question. Noncritical situations 

should be handled via the normal traffic alert procedures. 

a.  Terrain or Obstruction Alert 

1. 

Controllers will immediately issue an alert to the pilot of an aircraft under their control when they 

recognize that the aircraft is at an altitude which, in their judgment, may be in an unsafe proximity to 

Services Available to Pilots 

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