Installation Instructions

GTN 6XX/7XX AML STC Installation Manual 190-01007-A3
Page 2-14 Rev. 4
2.4.2.1 Multiple Uncorrected Pressure Altitude Sources
The GTN unit can accept uncorrected pressure altitude from multiple ARINC 429 and RS-232 sources.
If multiple sources of altitude data are supplied to the GTN, 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 altitude sources are as follows from highest to lowest:
1. ARINC 429 label 203 from Airdata
2. ARINC 429 label 203 from Airdata/AHRS
3. ARINC 429 label 203 from GDU Format 1, 2, 3, or 4
4. ARINC 429 label 203 from EFIS Format 2
5. ARINC 429 label 203 from Data Concentrator
6. ARINC 429 label 203 Traffic Format 1, 2, 3, 4, 5, or 6
7. RS-232 FADC Format 1 or Airdata Format 1
8. RS-232 Altitude Format 1 or 3
NOTE
Only certain altitude sources are acceptable for providing altitude to the GDL 88.
Refer to Section 2.4.3 for more information.
2.4.2.2 Multiple Baro-Corrected Altitude Sources
NOTE
Barometric altitude is not required by the GTN unit to meet the requirements of TSO-
C146c; however, 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.
The GTN unit can accept baro-corrected altitude from multiple ARINC 429 and RS-232 sources.
If multiple sources of baro-corrected altitude data are supplied to the GTN, 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 label 204 from Airdata
2. ARINC 429 label 204 from GDU Format 1
3. ARINC 429 label 204 from EFIS Format 1, 2, 3, or 4
4. ARINC 429 label 204 from Data Concentrator
5. RS-232 FADC Format 1 or Airdata Format 1