GNS 400W Series Installation Manual Page 2-1190-00356-08 Rev. G2 INSTALLATION OVERVIEW2.1 IntroductionAlways follow acceptable avionics installation practices per AC 43.13-1B, AC 43.13-2B, or later FAAapproved revisions of these documents. The GPS/WAAS installation instructions have been prepared tomeet the guidance material contained in AC 20-138C ―Position and Navigation Systems‖. Thecommunications installation instructions have been prepared to meet the guidance material defined byAC 20-67B, ―Airborne VHF Communications Equipment Installations‖.2.2 Minimum System Configuration2.2.1 VFR InstallationThe minimum 400W Series unit installation requires the following items for a VFR Installation:GNS 400W Series unit (installed in the aircraft manufacturer approved location for 6.25 inchwide avionics equipment).GPS antenna is required for GPS navigation functions.An external CDI is required for installations using VOR navigation and glideslope information.A NAV antenna is required for VHF NAV functions.A COM antenna is required for COM functions.VFR installations must be placarded ―GPS LIMITED TO VFR USE ONLY‖ in clear view of the pilot.2.2.2 IFR GPS InstallationIn order for the 400W Series unit to be utilized for IFR GPS Navigation, the criteria in Section 2.2.1 mustbe met in addition to the following:An External CDI/HSI indicator must be installed in the pilot‘s primary field-of-view (or in theaircraft manufacturer approved mounting location). The indicator must have a vertical deviationindicator (GS) in order to perform VNAV operations / approaches.Any annunciation required for Source Selection or IFR GPS Navigation must meet acceptablefield-of-view requirements.NOTETo take full advantage of the 400W Series unit capabilities, an optional barometricaltitude source is recommended for automatic sequencing of fix-to-altitude (FA) andhold-to-altitude (HA) leg types. If no barometric altitude data is provided to the400W Series unit, FA and HA legs must be manually sequenced.
