Installation Overview; Introduction; Minimum System Configuration; Vfr Gps Installation - Garmin GTN 625 Installation Manual

3 INSTALLATION OVERVIEW

3.1 Introduction

Always follow acceptable avionics installation practices per AC 43.13-1B, AC 43.13-2B, or later FAA
approved revisions. GPS/SBAS installation instructions have been prepared to meet the guidance material
contained in AC 20-138C "Positioning and Navigation Systems." Communications installation
instructions have been prepared to meet the guidance material defined by AC 20-67B, "Airborne VHF
Communications Equipment Installations."

3.2 Minimum System Configuration

3.2.1

VFR GPS Installation

Minimum GTN installation requires the following items for a VFR Installation:
 GTN 625/635/650 (installed in the aircraft manufacturer approved location for 6.25" wide
avionics equipment)
 GPS/SBAS antenna is required for GPS/SBAS navigation functions.
 An external CDI is required for installations using the VOR navigation, localizer and glideslope
information.
 A NAV antenna is required for VHF NAV functions. (GTN 650 only)

A COM antenna is required for COM functions. (GTN 635/650 only)
VFR installations must be placarded "GPS LIMITED TO VFR USE ONLY" in clear view of the pilot. The
placard must be located immediately adjacent to the GTN.
3.2.2

IFR Installation of a GTN 625/635

For an IFR installation of a GTN 625, the criteria in Section 3.2.1 must be met in addition to the following:
 An external CDI/HSI indicator must be installed in the pilot's primary field-of-view (or in the
aircraft manufacturer approved mounting location). The indicator must have a vertical deviation
indicator (GS) in order to perform approaches with vertical guidance.

If the GTN does not meet the field of view requirements, then remote source selection
annunciations must be installed. The GTN provides these annunciations if mounted within the
required field-of-view.
 Either a second GPS navigator (Garmin or non-Garmin) or a separate VHF navigation radio must
be installed. See Section 3.2.3 if installing a GTN 650.
NOTE
To take full advantage of the GTN unit capabilities, an optional barometric altitude source
is recommended for automatic sequencing of altitude leg types. If no barometric altitude
data is provided to the GTN unit, altitude leg types must be manually sequenced.
190-01004-02
Rev. F
GTN 625/635/650 TSO Installation Manual
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