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GNS 400W Series Maintenance Manual
Page 2-1
190-00356-05
Rev. A
SECTION 2
UNIT DESCRIPTION
This section gives a brief decsription of each unit in the GNS 400W series.
2.1 INTRODUCTION
All units in the 400W series are 6.25 inches wide and 2.66 inches high. The display on all units is
a 240 by 128 pixel color LCD. All units include two removable data cards, one with a Jeppesen
database (which is inserted in the left card slot), and the second a terrain database (which is
inserted in the right card slot). The GPS 400W is a GPS/WAAS unit that meets the requirements
of Technical Standard Order (TSO)-C146a and is approved for IFR en route, terminal, non-
precision, and precision approach operations.
The GNC 420W/(AW) includes all the features of the GPS 400W but includes a VHF
communications transceiver. The “AW” designates a 28 V dc unit with a 16 watt COM
transmitter. The GNS 430W/(AW) includes all the features of the GNC 420W/(AW), but includes
airborne VOR/localizer (LOC) and glideslope (G/S) receivers. The “AW” model designates a 28
V dc unit with a 16 watt com transmitter.
Table 2-1 summarizes the board configuration for each unit.
Table 2-1. Unit Configuration
Main
Board
Inverter
Board
Interface
Board
WAAS
GPS
Module
COM
Board
NAV
Board
GS
Board
GPS 400W
•
•
•
•
GNC 420W
•
•
•
•
•
GNC 420AW
•
•
•
•
•
GNS 430W
•
•
•
•
•
•
•
GNS 430AW
•
•
•
•
•
•
•