Important Codes:
1200
The VFR code for any altitude in the US (Refer to ICAO standards elsewhere)
7000
The VFR code commonly used in Europe (Refer to ICAO standards)
7500
Hijack code (Aircraft is subject to unlawful interference)
7600
Loss of communications
7700
Emergency
7777
Military interceptor operations (Never squawk this code)
0000
Military use
Avoid selecting codes 0000, 7500, and all codes in the 7600-7777 range. These codes
trigger special indicators in automated facilities. An aircraft’s transponder code is used for ATC
tracking purposes, therefore exercise care when making routine code changes!
Keys for Other GTX 328 Functions
IDENT
Pressing the
IDENT
Key activates the Special Position Identifica-
tion (SPI) Pulse for 18 seconds, identifying your transponder return from
others on the air traffic controller’s screen. The word ‘IDENT’ will appear in
the upper left corner of the display while the IDENT mode is active.
VFR
Sets the transponder code to the pre-programmed VFR code selected
in Configuration Mode (this is set to 7000 at the factory). Pressing the
VFR
Key again restores the previous identification code. If the VFR Key is
disabled (dependent upon installation configuration) a ‘VFR Key Disabled’
message appears, to indicate that no operation took place.
FUNC
Changes the page shown on the right side of the display. Display
data includes Pressure Altitude, Flight Time, Altitude Monitor, Count Up
and Count Down timers. Also displays Outside Air Temperature, Density
Altitude, Contrast, and Display (dependent upon installation configuration).
START/STOP
Starts and stops the Altitude Monitor, Count Up, Count
Down and Flight timers.
CRSR
Initiates starting time entry for the Count Down timer and cancels
transponder code entry.
CLR
Resets the Count Up, Count Down and Flight timers. Cancels the
previous keypress during code selection and Count Down entry. Returns
cursor to the fourth code digit within five seconds after entry.
8
Reduces Contrast and Display Brightness when the respective fields
are displayed (dependent upon installation configuration) and enters the
number eight into the Count Down timer.
9
Increases Contrast and Display Brightness when the respective fields
are displayed (dependent upon installation configuration) and enters the
number nine into the Count Down timer.
