Garmin GTX 3X5 Series Installation Manual page 185

CS-ACNS SECTION
CS ACNS.D.ELS.015 Data Transmission
(continued)
CS ACNS.D.ELS.020 On-the-Ground Status
Determination
CS ACNS.D.ELS.025 Altitude Source
190-01499-02
Rev. 9
CS-ACNS ITEM DESCRIPTION
2. If the system transmits additional
parameters on the extended squitter and if
their full compliance with CS ACNS.D.ADSB
has not been verified, as a minimum the
aircraft identification, pressure altitude,
ICAO 24-bit aircraft address is identical to
those transmitted in the Mode S replies.
Additionally the position and velocity
quality indicators reports the lowest quality.
a) The on-the-ground status is not set by a
manual action.
b) If automatic determination of the on-the-
ground status is not available, the on-the
ground status is set to airborne.
a) The reported pressure altitude is obtained
from an approved source.
b) The altitude resolution is equal to or less
than 30.48 m (100 ft.).
c) The altitude source connected to the active
transponder is the source being used to fly
the aircraft.
CS-ACNS Compliance Matrix
COMPLIANCE SUMMARY
The installation data requires a transponder / ADS-B test
to be run IAW Part 43 applicable regulatory tests.
The GTX 335/335R/345/345R software's air/ground state
will be automatically determined based on emitter
category, remote air/ground state, ground speed, GPS
track, airspeed, squat switch, height above terrain, and
radio altitude when possible. The on-the-ground status
cannot be set my manual action.
The GTX 335/335R/345/345R units will report the
airborne state in FS fields 4, 5, 20, 21 and the CA field of
DF 11. Furthermore, DF 11 provides the additional
capability of identifying if the aircraft didn't know the air/
ground state by transmitting a CA code of 6 or 7 which
still translates to an AIRBORNE state.
The installation manual provides approved altitude
interfaces.
When the unit retrieves valid pressure altitude data, the
unit sets the altitude precision of the system based on the
data source and the precision field, with a worst-case
resolution of 100ft.
The GTX 335/335R/345/345R provides the option to
utilize the Garmin Altitude Encoder which interfaces to
the existing aircraft static system and provides the altitude
data via I2C to the GTX. It is required to conduct a
transponder test upon completion of the installation,
which also requires an altitude inspection to compare the
input altitude to the aircraft altitude and broadcasted
altitude.
GTX 3X5 Transponder TSO Installation Manual
Page E-4