background image

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