AIM 

4/20/23

 

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Airport Operations

1. Upwind leg.

A flight path parallel to the landing runway in the direction of landing.

2. Crosswind leg.

A flight path at right angles to the landing runway off its takeoff end.

3. Downwind leg.

A flight path parallel to the landing runway in the opposite direction of landing.

4. Base leg.

A flight path at right angles to the landing runway off its approach end and extending from

the downwind leg to the intersection of the extended runway centerline.

5. Final approach.

A flight path in the direction of landing along the extended runway centerline from the

base leg to the runway.

6. Departure.

The flight path which begins after takeoff and continues straight ahead along the extended

runway centerline. The departure climb continues until reaching a point at least 

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 mile beyond the departure

end of the runway and within 300 feet of the traffic pattern altitude.

d.

Many towers are equipped with a tower radar display. The radar uses are intended to enhance the

effectiveness and efficiency of the local control, or tower, position. They are not intended to provide radar
services or benefits to pilots except as they may accrue through a more efficient tower operation. The four basic
uses are:

1. To determine an aircraft’s exact location.

 

This is accomplished by radar identifying the VFR aircraft

through any of the techniques available to a radar position, such as having the aircraft 

squawk ident

. Once

identified, the aircraft’s position and spatial relationship to other aircraft can be quickly determined, and standard
instructions regarding VFR operation in Class B, Class C, and Class D surface areas will be issued. Once initial
radar identification of a VFR aircraft has been established and the appropriate instructions have been issued,
radar monitoring may be discontinued; the reason being that the local controller’s primary means of surveillance
in VFR conditions is visually scanning the airport and local area.

2. To provide radar traffic advisories.

Radar traffic advisories may be provided to the extent that the

local controller is able to monitor the radar display. Local control has primary control responsibilities to the
aircraft operating on the runways, which will normally supersede radar monitoring duties.

3. To provide a direction or suggested heading. 

The local controller may provide pilots flying VFR with

generalized instructions which will facilitate operations; e.g., “PROCEED SOUTHWESTBOUND, ENTER A
RIGHT DOWNWIND RUNWAY THREE ZERO,” or provide a suggested heading to establish radar
identification or as an advisory aid to navigation; e.g., “SUGGESTED HEADING TWO TWO ZERO, FOR
RADAR IDENTIFICATION.” In both cases, the instructions are advisory aids to the pilot flying VFR and are
not radar vectors.

NOTE

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Pilots have complete discretion regarding acceptance of the suggested headings or directions and have sole responsibility
for seeing and avoiding other aircraft.

4. To provide information and instructions to aircraft operating within Class B, Class C, and Class D

surface areas.

In an example of this situation, the local controller would use the radar to advise a pilot on an

extended downwind when to turn base leg.

NOTE

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The above tower radar applications are intended to augment the standard functions of the local control position. There is
no controller requirement to maintain constant radar identification. In fact, such a requirement could compromise the local
controller’s ability to visually scan the airport and local area to meet FAA responsibilities to the aircraft operating on the
runways and within the Class B, Class C, and Class D surface areas. Normally, pilots will not be advised of being in radar
contact since that continued status cannot be guaranteed and since the purpose of the radar identification is not to establish
a link for the provision of radar services.

e.

A few of the radar equipped towers are authorized to use the radar to ensure separation between aircraft in

specific situations, while still others may function as limited radar approach controls. The various radar uses are
strictly a function of FAA operational need. The facilities may be indistinguishable to pilots since they are all
referred to as tower and no publication lists the degree of radar use. Therefore, when in communication with a