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capability unless the receiver has been upgraded. Receivers capable of
flying LP procedures must contain a statement in

the Aircraft Flight Manual (AFM), AFM Supplement, or Approved
Supplemental Flight Manual stating that the receiver has

LP capability, as well as the capability for the other WAAS and GPS
approach procedure types.

WAAS provides a level of service that supports all phases of flight,
including RNAV (GPS) approaches

to LNAV, LP, LNAV/VNAV, and LPV lines of minima, within system
coverage. Some locations close to the edge

of the coverage may have a lower availability of vertical guidance.

c.  General Requirements

WAAS avionics must be certified in accordance with
Technical Standard Order (TSO) TSO

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C145(),

Airborne Navigation Sensors Using the (GPS) Augmented by the Wide Area
Augmentation System (WAAS);

or TSO

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C146(), Stand

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Alone Airborne Navigation Equipment Using the Global Positioning System
(GPS)

Augmented by the Wide Area Augmentation System (WAAS), and installed in
accordance with AC 20

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Airworthiness Approval of Positioning and Navigation Systems.

GPS/WAAS operation must be conducted in accordance with the FAA

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approved aircraft flight manual

(AFM) and flight manual supplements. Flight manual supplements will
state the level of approach procedure that

the receiver supports. IFR approved WAAS receivers support all GPS only
operations as long as lateral capability

at the appropriate level is functional. WAAS monitors both GPS and WAAS
satellites and provides integrity.

GPS/WAAS equipment is inherently capable of supporting oceanic and
remote operations if the operator

obtains a fault detection and exclusion (FDE) prediction program.

Air carrier and commercial operators must meet the appropriate
provisions of their approved operations

specifications.

Prior to GPS/WAAS IFR operation, the pilot must review appropriate Noti
ces to Air Missions

(NOTAMs) and aeronautical information. This information is available on
request from a Flight Service Station.

The FAA will provide NOTAMs to advise pilots of the status of the WAAS
and level of service available.

(a)

The term MAY NOT BE AVBL is used in conjunction with WAAS NOTAMs and
indicates that due

to ionospheric conditions, lateral guidance may still be available when
vertical guidance is unavailable. Under

certain conditions, both lateral and vertical guidance may be
unavailable. This NOTAM language is an advisory

to pilots indicating the expected level of WAAS service
(LNAV/VNAV, LPV, LP) may not be available.

EXAMPLE

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!FDC FDC NAV WAAS VNAV/LPV/LP MINIMA MAY NOT BE AVBL
1306111330-1306141930EST

or

!FDC FDC NAV WAAS VNAV/LPV MINIMA NOT AVBL, WAAS LP MINIMA MAY NOT BE A
VBL

1306021200-1306031200EST

WAAS MAY NOT BE AVBL NOTAMs are predictive in nature and published for
flight planning purposes.

Upon commencing an approach at locations NOTAMed WAAS MAY NOT BE
AVBL, if the WAAS avionics

indicate LNAV/VNAV or LPV service is available, then vertical guidance
may be used to complete the approach

using the displayed level of service. Should an outage occur during the
approach, reversion to LNAV minima

or an alternate instrument approach procedure may be required. When GPS
testing NOTAMS are published and

testing is actually occurring, Air Traffic Control will advise pilots
requesting or cleared for a GPS or RNAV

(GPS) approach that GPS may not be available and request intentions. If
pilots have reported GPS anomalies,

Air Traffic Control will request the pilot's intentions and/or clear
the pilot for an alternate approach, if available

and operational.

(b)

WAAS area-wide NOTAMs are originated when WAAS assets are out of
service and impact the

service area. Area

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wide WAAS NOT AVAILABLE (AVBL) NOTAMs indicate loss or malfunction of
the

WAAS system. In flight, Air Traffic Control will advise pilots
requesting a GPS or RNAV (GPS) approach of

WAAS NOT AVBL NOTAMs if not contained in the ATIS broadcast.

EXAMPLE

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For unscheduled loss of signal or service, an example
NOTAM is: !FDC FDC NAV WAAS NOT AVBL 1311160600

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Navigation Aids