Ifr Vor/Loc/Gs Installation; External Sensors; Multiple Uncorrected Pressure Altitude Sources; Multiple Baro-Corrected Altitude Sources - Garmin GPS 400W Installation Manual

2.2.3

IFR VOR/LOC/GS Installation

The minimum GNS 430W installation requires the following items for an IFR VOR/LOC/GS Installation:
GNS 430W (installed in the aircraft manufacturer approved location)
GPS antenna, VOR/LOC antenna, glideslope antenna, and COM antenna.
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 for glideslope and VNAV operations/approaches.
Any annunciation required for Source Selection or IFR GPS Navigation must meet the acceptable
field-of-view requirements as noted in Section 2.5.1.
2.3

External Sensors

When the 400W Series unit is installed with external sensors, these sensors must be installed in
accordance with the manufacturer's data. This manual does not provide information for the installation of
specific external sensors.
The 400W Series unit can accept data from multiple altitude, heading, and baro correction sources. If
multiple sources are used, the 400W Series unit will accept data as described below.
Barometric altitude is not required by the 400W Series unit to meet the requirements of
TSO C146a.
2.3.1

Multiple Uncorrected Pressure Altitude Sources

The 400W Series can accept altitude from a Gray code or RS-232 altitude encoder, fuel/air data computer
(FADC), ARINC 429 air data computer (ADC), ARINC 429 EFIS, and ARINC 429 traffic advisory
system.
If multiple sources of altitude data are supplied to the 400W Series unit, only valid data from the highest
priority source is used (input priority cannot be configured). If the highest priority source becomes
unavailable, data is taken from the next-highest priority source. The priorities of the altitude sources are
as follows (from highest to lowest):
1. ARINC 429 ADC
2. ARINC 429 EFIS
3. ARINC 429 traffic advisory system
4. RS-232 FADC
5. RS-232 Altitude Encoder
6. Parallel Altitude Encoder (Gray code)
2.3.2

Multiple Baro-Corrected Altitude Sources

The 400W Series can accept baro-corrected altitude from an ARINC 429 ADC, ARINC 429 EFIS,
RS-232 FADC, and GTX 33/330 transponder.
If multiple sources of baro-corrected altitude data are supplied to the 400W Series unit, only valid data
from the highest priority source is used. If the highest priority source becomes unavailable, data is taken
from the next-highest priority source. The priorities of the baro-corrected altitude sources are as follows
(from highest to lowest):
1. ARINC 429 ADC
2. ARINC 429 EFIS
Page 2-2
Rev. G
NOTE
400W Series Installation Manual
190-00356-02