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AIM

10/12/17

5−4−35

Arrival Procedures

and plans to fly level for 30 seconds outbound before starting the turn back to the fix on final approach. If the winds were

negligible at flight altitude, this procedure would bring the pilot inbound across the fix precisely at the specified time of

12:07. However, if expecting headwind on final approach, the pilot should shorten the 30 second outbound course somewhat,

knowing that the wind will carry the aircraft away from the fix faster while outbound and decrease the ground speed while

returning to the fix. On the other hand, compensating for a tailwind on final approach, the pilot should lengthen the

calculated 30 second outbound heading somewhat, knowing that the wind would tend to hold the aircraft closer to the fix

while outbound and increase the ground speed while returning to the fix.

5−4−11. Radar Approaches

a. The only airborne radio equipment required for

radar approaches is a functioning radio transmitter

and receiver. The radar controller vectors the aircraft

to align it with the runway centerline. The controller

continues the vectors to keep the aircraft on course

until the pilot can complete the approach and landing

by visual reference to the surface. There are two types

of radar approaches: Precision (PAR) and Surveil-

lance (ASR).

b. A radar approach may be given to any aircraft

upon request and may be offered to pilots of aircraft

in distress or to expedite traffic, however, an ASR

might not be approved unless there is an ATC

operational requirement, or in an unusual or

emergency situation. Acceptance of a PAR or ASR by

a pilot does not waive the prescribed weather

minimums for the airport or for the particular aircraft

operator concerned. The decision to make a radar

approach when the reported weather is below the

established minimums rests with the pilot.

c. PAR and ASR minimums are published on

separate pages in the FAA Terminal Procedures

Publication (TPP).

1. Precision Approach (PAR). A PAR is one in

which a controller provides highly accurate naviga-

tional guidance in azimuth and elevation to a pilot.

Pilots are given headings to fly, to direct them to, and

keep their aircraft aligned with the extended

centerline of the landing runway. They are told to

anticipate glidepath interception approximately 10 to

30 seconds before it occurs and when to start descent.

The published Decision Height will be given only if

the pilot requests it. If the aircraft is observed to

deviate above or below the glidepath, the pilot is

given the relative amount of deviation by use of terms

“slightly” or “well” and is expected to adjust the

aircraft’s rate of descent/ascent to return to the

glidepath. Trend information is also issued with

respect to the elevation of the aircraft and may be

modified by the terms “rapidly” and “slowly”;

e.g., “well above glidepath, coming down rapidly.”

Range from touchdown is given at least once each

mile. If an aircraft is observed by the controller to

proceed outside of specified safety zone limits in

azimuth and/or elevation and continue to operate

outside these prescribed limits, the pilot will be

directed to execute a missed approach or to fly a

specified course unless the pilot has the runway

environment (runway, approach lights, etc.) in sight.

Navigational guidance in azimuth and elevation is

provided the pilot until the aircraft reaches the

published Decision Height (DH). Advisory course

and glidepath information is furnished by the

controller until the aircraft passes over the landing

threshold, at which point the pilot is advised of any

deviation from the runway centerline. Radar service

is automatically terminated upon completion of the

approach.

2. Surveillance Approach (ASR). An ASR is

one in which a controller provides navigational

guidance in azimuth only. The pilot is furnished

headings to fly to align the aircraft with the extended

centerline of the landing runway. Since the radar

information used for a surveillance approach is

considerably less precise than that used for a

precision approach, the accuracy of the approach will

not be as great and higher minimums will apply.

Guidance in elevation is not possible but the pilot will

be advised when to commence descent to the

Minimum Descent Altitude (MDA) or, if appropriate,

to an intermediate step−down fix Minimum Crossing

Altitude and subsequently to the prescribed MDA. In

addition, the pilot will be advised of the location of

the Missed Approach Point (MAP) prescribed for the

procedure and the aircraft’s position each mile on

final from the runway, airport or heliport or MAP, as

appropriate. If requested by the pilot, recommended

altitudes will be issued at each mile, based on the

descent gradient established for the procedure, down

to the last mile that is at or above the MDA. Normally,

navigational guidance will be provided until the

aircraft reaches the MAP. Controllers will terminate

guidance and instruct the pilot to execute a missed

approach unless at the MAP the pilot has the runway,

3/29/18

AIM