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AIM

10/12/17

5−4−7

Arrival Procedures

Manhattan altimeter setting; when not available use

Salina altimeter setting and increase all MDAs

40 feet. When the altimeter must be obtained from a

source other than air traffic a note will indicate the

source; e.g., Obtain local altimeter setting on CTAF.

When the altimeter setting(s) on which the approach

is based is not available, the approach is not

authorized. Baro−VNAV must be flown using the

local altimeter setting only. Where no local altimeter

is available, the LNAV/VNAV line will still be

published for use by WAAS receivers with a note that

Baro−VNAV is not authorized. When a local and at

least one other altimeter setting source is authorized

and the local altimeter is not available Baro−VNAV

is not authorized; however, the LNAV/VNAV

minima can still be used by WAAS receivers using the

alternate altimeter setting source.

NOTE−

Barometric Vertical Navigation (baro−VNAV).  An RNAV

system function which uses barometric altitude informa-

tion from the aircraft’s altimeter to compute and present

a vertical guidance path to the pilot. The specified vertical

path is computed as a geometric path, typically computed

between two waypoints or an angle based computation

from a single waypoint.  Further guidance may be found in

Advisory Circular 90−105.

5. A pilot adhering to the altitudes, flight paths,

and weather minimums depicted on the IAP chart or

vectors and altitudes issued by the radar controller, is

assured of terrain and obstruction clearance and

runway or airport alignment during approach for

landing.

6. IAPs are designed to provide an IFR descent

from the en route environment to a point where a safe

landing can be made. They are prescribed and

approved by appropriate civil or military authority to

ensure a safe descent during instrument flight

conditions at a specific airport. It is important that

pilots understand these procedures and their use prior

to attempting to fly instrument approaches.

7. TERPS criteria are provided for the following

types of instrument approach procedures:

(a) Precision Approach (PA). An instrument

approach based on a navigation system that provides

course and glidepath deviation information meeting

the precision standards of ICAO Annex 10. For

example, PAR, ILS, and GLS are precision

approaches.

(b) Approach with Vertical Guidance (APV).

An instrument approach based on a navigation

system that is not required to meet the precision

approach standards of ICAO Annex 10 but provides

course and glidepath deviation information. For

example, Baro−VNAV, LDA with glidepath, LNAV/

VNAV and LPV are APV approaches.

(c) Nonprecision Approach (NPA). An in-

strument approach based on a navigation system

which provides course deviation information, but no

glidepath deviation information. For example, VOR,

NDB and LNAV. As noted in subparagraph k, Vertical

Descent Angle (VDA) on Nonprecision Approaches,

some approach procedures may provide a Vertical

Descent Angle as an aid in flying a stabilized

approach, without requiring its use in order to fly the

procedure. This does not make the approach an APV

procedure, since it must still be flown to an MDA and

has not been evaluated with a glidepath.

b. The method used to depict prescribed altitudes

on instrument approach charts differs according to

techniques employed by different chart publishers.

Prescribed altitudes may be depicted in four different

configurations: minimum, maximum, mandatory,

and recommended. The U.S. Government distributes

charts produced by National Geospatial−Intelligence

Agency (NGA) and FAA. Altitudes are depicted on

these charts in the profile view with underscore,

overscore, both or none to identify them as minimum,

maximum, mandatory or recommended.

1. Minimum altitude will be depicted with the

altitude value underscored. Aircraft are required to

maintain altitude at or above the depicted value,

e.g., 3000.

2. Maximum altitude will be depicted with the

altitude value overscored. Aircraft are required to

maintain altitude at or below the depicted value,

e.g., 4000.

3. Mandatory altitude will be depicted with the

altitude value both underscored and overscored.

Aircraft are required to maintain altitude at the

depicted value, e.g., 5000.

4. Recommended altitude will be depicted with

no overscore or underscore. These altitudes are

depicted for descent planning, e.g., 6000.

NOTE−

1. Pilots are cautioned to adhere to altitudes as prescribed

because, in certain instances, they may be used as the basis

for vertical separation of aircraft by ATC. When a depicted

2/28/19

AIM