AIM
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Navigation Aids
are being named, in addition to being identified by
ATD. However, since most GPS avionics do not
accommodate waypoints between the FAF and MAP,
even when the waypoint is named, the waypoints for
these stepdown fixes may not appear in the sequence
of waypoints in the navigation database. Pilots must
continue to identify these stepdown fixes using ATD.
o. Missed Approach
1. A GPS missed approach requires pilot
action
to sequence the receiver past the MAWP to the
missed approach portion of the procedure. The pilot
must be thoroughly familiar with the activation
procedure for the particular GPS receiver installed in
the aircraft and must initiate appropriate action
after the MAWP.
Activating the missed approach
prior to the MAWP will cause CDI sensitivity to
immediately change to terminal (
±1NM) sensitivity
and the receiver will continue to navigate to the
MAWP. The receiver will not sequence past the
MAWP. Turns should not begin prior to the MAWP.
If the missed approach is not activated, the GPS
receiver will display an extension of the inbound final
approach course and the ATD will increase from the
MAWP until it is manually sequenced after crossing
the MAWP.
2.
Missed approach routings in which the first
track is via a course rather than direct to the next
waypoint require additional action by the pilot to
set the course. Being familiar with all of the inputs
required is especially critical during this phase of
flight.
p. GPS Familiarization
Pilots should practice GPS approaches under visual
meteorological conditions (VMC) until thoroughly
proficient with all aspects of their equipment
(receiver and installation) prior to attempting flight
by IFR in instrument meteorological conditions
(IMC). Some of the areas which the pilot should
practice are:
1.
Utilizing the receiver autonomous integrity
monitoring (RAIM) prediction function;
2.
Inserting a DP into the flight plan, including
setting terminal CDI sensitivity, if required, and the
conditions under which terminal RAIM is available
for departure (some receivers are not DP or STAR
capable);
3.
Programming the destination airport;
4.
Programming and flying the overlay ap-
proaches (especially procedure turns and arcs);
5.
Changing to another approach after selecting
an approach;
6.
Programming and flying “direct” missed
approaches;
7.
Programming and flying “routed” missed
approaches;
8.
Entering, flying, and exiting holding patterns,
particularly on overlay approaches with a second
waypoint in the holding pattern;
9.
Programming and flying a “route” from a
holding pattern;
10.
Programming and flying an approach with
radar vectors to the intermediate segment;
11.
Indication of the actions required for RAIM
failure both before and after the FAWP; and
12.
Programming a radial and distance from a
VOR (often used in departure instructions).
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19. Wide Area Augmentation System
(WAAS)
a. General
1.
The FAA developed the Wide Area Aug-
mentation System (WAAS) to improve the accuracy,
integrity and availability of GPS signals. WAAS will
allow GPS to be used, as the aviation navigation
system, from takeoff through Category I precision
approach when it is complete. WAAS is a critical
component of the FAA’s strategic objective for a
seamless satellite navigation system for civil
aviation, improving capacity and safety.
2.
The International Civil Aviation Organiza-
tion (ICAO) has defined Standards and
Recommended Practices (SARPs) for satellite−based
augmentation systems (SBAS) such as WAAS. Japan
and Europe are building similar systems that are
planned to be interoperable with WAAS: EGNOS,
the European Geostationary Navigation Overlay
System, and MSAS, the Japan Multifunctional
Transport Satellite (MTSAT) Satellite−based Aug-
mentation System. The merging of these systems will
create a worldwide seamless navigation capability
similar to GPS but with greater accuracy, availability
and integrity.
3.
Unlike traditional ground−based navigation
aids, WAAS will cover a more extensive service area.