Garmin APOLLO GX65 - Manual (Page 220)

to predict whether RAIM will be available at the
estimated time of arrival at the destination. Your
Apollo GX provides you with a RAIM prediction
page. This page allows you to determine if RAIM
should be available at any location and time. If it says
RAIM will be available, it actually means that it will
be available at your predicted time of arrival and plus
and minus 15 minutes from your arrival time
calculated at 5 minute intervals.
RAIM prediction is required to be done automatically
by the equipment for the estimated time of arrival at
the FAF and the MAP when you are 3 nm inbound to
the FAF.
TSO C129 requires the RAIM alarm limit to be at
least 2.0 nm for en route operations, 1.0 nm for
Terminal operations, and 0.3 nm for Approach
operations.
What are En Route, Terminal, and Approach
Operations?
Approach RAIM, or 0.3 nm alarm limit, is provided
from 2.0 nm inbound to the FAF until you cancel the
Approach Active operation (usually at the MAP).
Approach RAIM is provided only if an approach is
loaded into your active flight plan and it is enabled.
Terminal RAIM, or 1.0 nm alarm limit is provided
within 30 nm of your departure and your destination
airport (except when Approach RAIM is provided).
This is automatic and requires no pilot action. For
those of you who are familiar with the traditional
definition of Terminal, which was the ability to
operate on SIDs and STARs that are only 4 nm wide,
the term Terminal has been “redefined” in TSO C129
to mean within 30 nm of your departure or
destination.
9-30
Approach Basics (GX50/60)