AIM Basic w/ Chg 1, 2, and 3 dtd 9-5-24

AIM

4/20/23

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.

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11. Radar Approaches

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 Surveillance (ASR).

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.

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 navigational

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

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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, airport or heliport in sight or, for a helicopter point

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space approach, the prescribed visual

reference with the surface is established. Also, if, at any time during the approach the controller considers that

Arrival Procedures

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