Mutual Suppression Pulses; Tis System Capabilities - Garmin G900X Installation And Maintenance Manual

The GTX 33 with software version 4.01 meets Mode S Enhanced Surveillance requirements. Mode S
Enhanced Surveillance is used predominantly in European airspace. It provides information consisting of
additional aircraft parameters (see JAA NPA 20-12a) to ground radar systems. Compliance with
Enhanced Surveillance may require additional interface between aircraft systems and the GTX 33.

8.1.1 Mutual Suppression Pulses

Other equipment on board the aircraft may transmit in the same frequency band as the transponder, such
as DME or another transponder. Mutual suppression is a synchronous pulse that is sent to the other
equipment to suppress transmission of a competing transmitter for the duration of the pulse train
transmission. The transponder transmission is suppressed by an external source and other equipment on
board is suppressed by the GTX 33 transponder. This feature is designed to limit mutual interference.

8.1.2 TIS System Capabilities

Traffic Information Service (TIS) provides a graphic display of traffic advisory information in the cockpit
for non-TCAS equipped aircraft.
TIS is a ground-based service providing relative location of all ATCRBS Mode A and Mode C
transponder equipped aircraft within a specified service volume. The TIS ground sensor uses real time
track reports to generate traffic notification.
Traffic display is available to aircraft equipped with a Mode S data link such as the Garmin GTX 33
transponder. Traffic can then be displayed on the GDU 1040 Primary Flight Display.
Surveillance data includes all transponder equipped aircraft within the coverage volume. Aircraft without
an operating transponder are invisible to TIS. TIS displays traffic within seven nautical miles from 3000
feet below to 3500 feet above the requesting aircraft.
Page 8-2 G900X/G950 Installation and Maintenance Manual – GTX 33
Revision D 190-00719-00