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AIM

10/12/17

4

−3−2

Airport Operations

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 responsibi-
lities 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 SOUTH-
WESTBOUND, 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

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

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 tower
controller who may have radar available, do not
assume that constant radar monitoring and complete
ATC radar services are being provided

.

4

−3−3. Traffic Patterns

a.

It is recommended that aircraft enter the airport

traffic pattern at one of the following altitudes listed
below. These altitudes should be maintained unless
another traffic pattern altitude is published in the
Chart Supplement U.S. or unless otherwise required
by the applicable distance from cloud criteria
(14 CFR Section 91.155). (See FIG 4

−3−2 and

FIG 4

−3−3):

1.

Propeller

−driven aircraft enter the traffic

pattern at 1,000 feet above ground level (AGL).

2.

Large and turbine

−powered aircraft enter the

traffic pattern at an altitude of not less than 1,500 feet
AGL or 500 feet above the established pattern
altitude.

3.

Helicopters operating in the traffic pattern

may fly a pattern similar to the fixed

−wing aircraft

pattern, but at a lower altitude (500 AGL) and closer
to the runway. This pattern may be on the opposite
side of the runway from fixed

−wing traffic when

3/15/07

7110.65R CHG 2

AIM

3/29/18