AIM

4/3/14

5−4−21

Arrival Procedures

for a “normal” glidepath, due to its location down the

runway.

3.

Accordingly, pilots are advised to carefully

review approach procedures, prior to initiating the

approach, to identify the optimum position(s), and

any unacceptable positions, from which a descent to

landing can be initiated (in accordance with 14 CFR

Section 91.175(c)).

k. Area Navigation (RNAV) Instrument

Approach Charts. 

Reliance on RNAV systems for

instrument operations is becoming more common-

place as new systems such as GPS and augmented

GPS such as the Wide Area Augmentation System

(WAAS) are developed and deployed. In order to

support full integration of RNAV procedures into the

National Airspace System (NAS), the FAA

developed a new charting format for IAPs (See

FIG 5−4−9). This format avoids unnecessary

duplication and proliferation of instrument approach

charts. The original stand alone GPS charts, titled

simply “GPS,” are being converted to the newer

format as the procedures are revised. One reason for

the revision is the addition of WAAS based minima

to the approach chart. The reformatted approach chart

is titled “RNAV (GPS) RWY XX.” Up to four lines

of minima are included on these charts. Ground

Based Augmentation System (GBAS) Landing Sys-

tem (GLS) was a placeholder for future WAAS and

LAAS minima, and the minima was always listed as

N/A. The GLS minima line has now been replaced by

the WAAS LPV (Localizer Performance with

Vertical Guidance) minima on most RNAV (GPS)

charts. LNAV/VNAV (lateral navigation/vertical

navigation) was added to support both WAAS

electronic vertical guidance and Barometric VNAV.

LPV and LNAV/VNAV are both APV procedures as

described in paragraph 5−4−5a7. The original GPS

minima, titled “S−XX,” for straight in runway XX, is

retitled LNAV (lateral navigation). Circling minima

may also be published. A new type of nonprecision

WAAS minima will also be published on this chart

and titled LP (localizer performance). LP will be

published in locations where vertically guided

minima cannot be provided due to terrain and

obstacles and therefore, no LPV or LNAV/VNAV

minima will be published. GBAS procedures are pub-

lished on a separate chart and the GLS minima line is

to be used only for GBAS. ATC clearance for the

RNAV procedure authorizes a properly certified pilot

to utilize any minimums for which the aircraft is certi-

fied (for example, a WAAS equipped aircraft utilizes

the LPV or LP minima but a GPS only aircraft may

not). The RNAV chart includes information format-

ted for quick reference by the pilot or flight crew at the

top of the chart. This portion of the chart, developed

based on a study by the Department of Transporta-

tion, Volpe National Transportation System Center, is

commonly referred to as the pilot briefing.

1.

The minima lines are:

(a) GLS.

“GLS” is the acronym for GBAS

Landing System. The U.S. version of GBAS has

traditionally been referred to as LAAS. The

worldwide community has adopted GBAS as the

official term for this type of navigation system. To

coincide with international terminology, the FAA is

also adopting the term GBAS to be consistent with the

international community. This line was originally

published as a placeholder for both WAAS and LAAS

minima and marked as N/A since no minima was

published. As the concepts for GBAS and WAAS

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