Garmin 530w Guida Utente

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Fault Detection and Exclusion (FDE)

The Garmin 500W-series software incorporates 

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 for a satellite (and presumably, 
position error) for a given mode of flight. Upon detec-
tion, 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 flight 
(non-precision approach, terminal, en route). The FDE 
functionality for non-oceanic flight phases complies 
with missed alert probability, false alert probability and 
failed exclusion probability specified by DO-229C / 
TSO-C146a. 

Pre-departure Verification of FDE

An FDE prediction must be performed prior to 

departure for a flight 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 
400W/500W-series Trainer CD to demonstrate that 
there are no outages in the capability to navigate 
on the specified route of flight (the FDE prediction 
program determines whether the GPS constellation is 
robust enough to provide a navigation solution for the 
specified route of flight). Please, refer to the instruc-
tions included in the Garmin 400W/500W-series 
Training CD for complete details on using the FDE 
prediction program.