Section 11: Fault Detection And Exclusion (Fde) Interface - Garmin GNS 530 Pilot's Manual & Reference

11 - FDE
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Section 11: Fault Detection and Exclusion (FDE) Interface

NOTE: The following section is aimed at users who have experience operating the GNS 530 unit
and are familiar with the operation of RAIM.
Fault Detection and Exclusion (FDE)
The Garmin GNS 530 Main and GPS Software version 3.00 and higher incorporate a Fault Detection and
Exclusion (FDE) algorithm, thus providing a basis for approval per FAA Notice N8110.60 requirements for
"GPS as a Primary Means of Navigation for Oceanic/Remote Operations".
The FDE consists of two distinct features, fault detection and fault exclusion. The fault detection feature
detects the presence of an unacceptably large pseudorange error (and presumably, position error) for a given
mode of fl ight. Upon detection, fault exclusion follows and excludes the source of the unacceptably large
pseudorange error, thereby allowing navigation to return to normal performance without an interruption in
service. To enhance safety, FDE functionality is provided for other phases of fl ight (non-precision approach,
terminal, en route). The FDE functionality for non-oceanic fl ight phases adheres to the same missed alert
probability, false alert probability and failed exclusion probability specifi ed by FAA Notice N8110.60.
Pre-departure Verifi cation of FDE
An FDE prediction must be performed prior to departure for a fl ight plan involving Oceanic/Remote
operation where GPS is to be the sole source of navigation. Prior to departure, the operator must use the FDE
prediction program supplied with the GNS 530 Trainer Software to demonstrate that there are no outages in
the capability to navigate on the specifi ed route of fl ight (the FDE prediction program determines whether the
GPS constellation is robust enough to provide a navigation solution for the specifi ed route of fl ight). Please,
refer to the instructions included in the Garmin GNS 530 Simulator Interactive Training CD for complete
details on using the FDE prediction program.