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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