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AIM

4/20/23

5

4

23

Arrival Procedures

procedure publication have evolved, GLS will now be used only for GBAS minima, which will be on a separate
approach chart. Most RNAV(GPS) approach charts have had the GLS minima line replaced by a WAAS LPV
line of minima.

(b) LPV. 

“LPV” is the acronym for localizer performance with vertical guidance. RNAV (GPS)

approaches to LPV lines of minima take advantage of the improved accuracy of WAAS lateral and vertical
guidance to provide an approach that is very similar to a Category I Instrument Landing System (ILS). The
approach to LPV line of minima is designed for angular guidance with increasing sensitivity as the aircraft gets
closer to the runway. The sensitivities are nearly identical to those of the ILS at similar distances. This was done
intentionally to allow the skills required to proficiently fly an ILS to readily transfer to flying RNAV (GPS)
approaches to the LPV line of minima. Just as with an ILS, the LPV has vertical guidance and is flown to a DA.
Aircraft can fly this minima line with a statement in the Aircraft Flight Manual that the installed equipment
supports LPV approaches. This includes Class 3 and 4 TSO

C146 GPS/WAAS equipment.

(c) LNAV/VNAV.

 LNAV/VNAV identifies APV minimums developed to accommodate an RNAV IAP

with vertical guidance, usually provided by approach certified Baro

VNAV, but with lateral and vertical integrity

limits larger than a precision approach or LPV. LNAV stands for Lateral Navigation; VNAV stands for Vertical
Navigation. This minima line can be flown by aircraft with a statement in the Aircraft Flight Manual that the
installed equipment supports GPS approaches and has an approach

approved barometric VNAV, or if the aircraft

has been demonstrated to support LNAV/VNAV approaches. This includes Class 2, 3 and 4 TSO

C146

GPS/WAAS equipment. Aircraft using LNAV/VNAV minimums will descend to landing via an internally
generated descent path based on satellite or other approach approved VNAV systems. Since electronic vertical
guidance is provided, the minima will be published as a DA. Other navigation systems may be specifically
authorized to use this line of minima. (See Section A, Terms/Landing Minima Data, of the U.S. Terminal
Procedures books.)

(d) LP. 

“LP” is the acronym for localizer performance. Approaches to LP lines of minima take advantage

of the improved accuracy of WAAS to provide approaches, with lateral guidance and angular guidance. Angular
guidance does not refer to a glideslope angle but rather to the increased lateral sensitivity as the aircraft gets closer
to the runway, similar to localizer approaches. However, the LP line of minima is a Minimum Descent Altitude
(MDA) rather than a DA (H). Procedures with LP lines of minima will not be published with another approach
that contains approved vertical guidance (LNAV/VNAV or LPV). It is possible to have LP and LNAV published
on the same approach chart but LP will only be published if it provides lower minima than an LNAV line of
minima. LP is not a fail

down mode for LPV. LP will only be published if terrain, obstructions, or some other

reason prevent publishing a vertically guided procedure. WAAS avionics may provide GNSS

based advisory

vertical guidance during an approach to an LP line of minima. Barometric altimeter information remains the
primary altitude reference for complying with any altitude restrictions. WAAS equipment may not support LP,
even if it supports LPV, if it was approved before TSO

C145b and TSO

C146b. Receivers approved under

previous TSOs may require an upgrade by the manufacturer in order to be used to fly to LP minima. Receivers
approved for LP must have a statement in the approved Flight Manual or Supplemental Flight Manual including
LP as one of the approved approach types.

(e) LNAV. 

This minima is for lateral navigation only, and the approach minimum altitude will be

published as a minimum descent altitude (MDA). LNAV provides the same level of service as the present GPS
stand alone approaches. LNAV minimums support the following navigation systems: WAAS, when the
navigation solution will not support vertical navigation; and, GPS navigation systems which are presently
authorized to conduct GPS approaches.

NOTE

GPS receivers approved for approach operations in accordance with: AC 20

138, Airworthiness Approval of  Positioning

and Navigation Systems, qualify for this minima. WAAS navigation equipment must be approved in accordance with the
requirements specified in TSO

C145() or TSO

C146() and installed in accordance with Advisory Circular AC 20

138.

2.

Other systems may be authorized to utilize these approaches. See the description in Section A of the U.S.

Terminal Procedures books for details. Operational approval must also be obtained for Baro

VNAV systems to