AIM
12/2/21
RAIM outages for the aircraft’s predicted flight path
and times;
5.
Operators may use the receiver’s installed
RAIM prediction capability (for TSO
−
C129a/Class
A1/B1/C1 equipment) to provide non
−
precision
approach RAIM, accounting for the latest GPS
constellation status (for example, NOTAMs or
NANUs). Receiver non
−
precision approach RAIM
should be checked at airports spaced at intervals not
to exceed 60 NM along the RNAV 1 procedure’s
flight track. “Terminal” or “Approach” RAIM must
be available at the ETA over each airport checked; or,
6.
Operators not using model
−
specific software
or FAA/VOLPE RAIM data will need FAA
operational approval.
NOTE
−
If TSO
−
C145/C146 equipment is used to satisfy the RNAV
and RNP requirement, the pilot/operator need not perform
the prediction if WAAS coverage is confirmed to be
available along the entire route of flight. Outside the U.S.
or in areas where WAAS coverage is not available,
operators using TSO
−
C145/C146 receivers are required to
check GPS RAIM availability.
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17. Cold Temperature Operations
a.
Pilots should begin planning for cold tempera-
ture operations during the preflight planning phase.
Cold temperatures produce barometric altimetry
errors, which affect instrument flight procedures.
Currently there are two temperature limitations that
may be published in the notes box of the middle
briefing strip on an instrument approach procedure
(IAP). The two published temperature limitations
are:
1.
A temperature range limitation associated
with the use of baro
−
VNAV that may be published on
an United States PBN IAP titled RNAV (GPS) or
RNAV (RNP); and/or
2.
A Cold Temperature Airport (CTA) limita-
tion designated by a snowflake ICON and
temperature in Celsius (C) that is published on every
IAP for the airfield.
b.
Pilots should request the lowest forecast
temperature +/
−
1 hour for arrival and departure
operations. If the temperature is forecast to be outside
of the baro
−
VNAV or at or below the CTA
temperature limitation, consider the following:
1.
When using baro
−
VNAV with an aircraft that
does not have an automated temperature compensat-
ing function, pilots should plan to use the appropriate
minima and/or IAP.
(a)
The LNAV/VNAV line of minima on an
RNAV (GPS) may not be used without an approved
automated temperature compensating function if the
temperature is outside of the baro
−
VNAV tempera-
ture range limitation. The LNAV minima may be
used.
(b)
The RNAV (RNP) procedure may not be
accomplished without an approved automated
temperature compensating function if the tempera-
ture is outside of the baro
−
VNAV temperature range
limitation.
2.
If the temperature is forecast to be at or below
the published CTA temperature, pilots should
calculate a correction for the appropriate segment/s or
a correction for all the segments if using the “All
Segments Method.”
Pilots should review the operating procedures for the
aircraft’s temperature compensating system when
planning to use the system for any cold temperature
corrections. Any planned altitude correction for the
intermediate and/or missed approach holding seg-
ments must be coordinated with ATC. Pilots do not
have to advise ATC of a correction in the final
segment.
NOTE
−
The charted baro
−
VNAV temperature range limitation
does not apply to pilots operating aircraft with an
airworthiness approval to conduct an RNAV (GPS)
approach to LNAV/VNAV minimums with the use of SBAS
vertical guidance.
REFERENCE
−
AIM, Chapter 7, Section 3, Cold Temperature Barometric Altimeter
Errors, Setting Procedures, and Cold Temperature Airports (CTA).
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Preflight