Garmin GNC 420W Pilots Guide - Page 228

SECTION 12 - FAULT DETECTION AND EXCLUSION 12.2 Pre-Departure Verification of FDE Since FDE is based upon the exclusion of "bad" satellites, it is necessary to ensure there will be an adequate number of satellites in the GPS constellation that are still able to provide a navigation solution. An FDE prediction must be performed prior to departure for a flight involving: • Oceanic/Remote operation where GPS is to be the sole source of navigation per FAA Notice 8110.60. • U.S. Area Navigation (RNAV) routes, Standard Instrument Departures (SIDs), or Standard Terminal Arrival Routes (STARs) if a NOTAM indicates a GPS satellite (or satellites) is scheduled to be outof-service, per FAA AC 90-100 'U.S. Terminal and En Route Area Navigation (RNAV) Operations'. Prior to departure, the operator must use the FDE Prediction Program supplied with the 400-series Trainer Software (Figure 12-2) 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). The trainer software and the document "400/500-series FDE Prediction Instructions" (190-00643-00) are available on Garmin's website for free download (www.garmin.com). Figure 12-2 Garmin 400-Series Trainer Software . 12-2 GNC 420(A) Pilot's Guide and Reference 190-00140-20 Rev. K