GTN 625/635/650 TSO Installation Manual
Page 3-1
190-01004-02
Rev. C
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 20-138A ―Airworthiness Approval of Global Navigation Satellite System (GNSS)
Equipment.‖ 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 Installation
Minimum GTN installation requires the following items for a VFR Installation:
GTN (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.
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.
3.2.2
IFR GPS Installation in Reciprocating, Single-Engine Aircraft 6000 lbs or
Less
In order for the GTN unit to be utilized for IFR GPS Navigation, 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 VNAV operations/approaches.
GTN 625
A VHF COM Radio
Refer to Section 1.5.5 for AFM/AFMS/POH considerations.
In order for the GTN unit to be utilized for IFR GPS Navigation, 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 VNAV operations/approaches.
GTN 625
A VHF COM radio
A second GPS Navigator
or
a VHF NAV radio
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.
