Aeronautical Information Manual (AIM), page 356

Index   355 -- Page 356 -- 357


airport maintaining visual contact with the ground.
Altitude on the visual flight path is at the discretion
of the pilot, and it is the responsibility of the pilot to
visually acquire and avoid obstacles in the "Fly
Visual to Airport" segment.

2. Missed approach obstacle clearance is
assured only if the missed approach is commenced at
the published MAP. Before initiating an IAP that
contains a "Fly Visual to Airport" segment, the pilot
should have preplanned climb out options based on
aircraft performance and terrain features. Obstacle
clearance is the responsibility of the pilot when the
approach is continued beyond the MAP.
The FAA Administrator retains the authority to approve
instrument approach procedures where the pilot may not
necessarily have one of the visual references specified in
14 CFR § 91.175 and related rules. It is not a function of
procedure design to ensure compliance with § 91.175. The
annotation "Fly Visual to Airport" provides relief from
§ 91.175 requirements that the pilot have distinctly visible
and identifiable visual references prior to descent below

m. 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 5-4-5). 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N/A. The GLS minima line has now been replaced by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

5-4-20 Arrival Procedures

Page 356 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   355 -- Page 356 -- 357