The display shows the operating mode of the FDL-978-TX, the reported pressure altitude, and the current squawk code and Flight ID.
The reply indicator is active when the FDL-978-TX transmits ADS-B messages and is
displayed on the screen as shown.
The pressure altitude is displayed as a Flight Level which is the pressure altitude in
hundreds of feet. When non-standard atmospheric conditions apply this may not match
the altimeter indicated altitude but will be correctly reported by the ATC radar. The figure below
shows the FDL-978-TX powered on in its Airborne Transmission mode with a pressure altitude of
flight level 0 being displayed.
The left hand Mode knob controls the power to the FDL-978-TX and the operating mode. The knob rotates
between the different operating modes as defined in the table below.
OFF
Power is removed from the FDL-978-TX.
SBY
The FDL-978-TX is on but will not transmit any ADS-B messages.
GND
The FDL-978-TX is placed in Airborne Transmission Mode or automatically switches between Airborne
and Ground Mode if an Air/Grnd Squat switch is configured and the aircraft velocity meets the criteria
described in DO-282B for the specific aircraft configuration. Pressure altitude is reported.
ON
The FDL-978-TX is placed in Airborne Transmission Mode or automatically switches between Airborne
and Ground Mode if an Air/Grnd Squat switch is configured and the aircraft velocity meets the criteria
described in DO-282B for the specific aircraft configuration. Pressure altitude reporting is suppressed.
ALT
The FDL-978-TX is placed in Airborne Transmission Mode or automatically switches between Airborne
and Ground Mode if an Air/Grnd Squat switch is configured and the aircraft velocity meets the criteria
described in DO-282B for the specific aircraft configuration. Pressure altitude is reported.
There is no functional difference between the ALT and GND mode. Aircraft installations that include a gear squat switch
will automatically select GND on landing.
Push Buttons
IDT
Press the IDT
button when ATC instructs you to “Ident” or “Squawk Ident”.
FN
Pressing the FN
button provides access to changing the Call Sign/ Flight ID.
You may either directly rotate the code knob
or press the
key and the first character of the flight ID will
be highlighted. Use the rotary code knob
to select your choice of alpha-numeric characters. Press
again
and the cursor moves to the next character. You must present
each time all the way through the 8 characters
to save your Call Sign/ Flight ID change.
Pressing the
button again allows the pilot to view the FDL-978-TX present position being transmitted.
Pressing the
button again allows the pilot to view the Warning messages.
VFR
Pressing the VFR
button sets the ADS-B to the pre-programmed conspicuity code and VFR Flight ID.
Pressing the button again restores the previous squawk code and Flight ID.
ENT
The ENT
button enters a digit in the code selector.
The right hand knob is used to set squawk codes and the Flight ID. Press the FN button until the rotate the screen to display
either the squawk code or Flight ID at the top of the screen. Turning the knob will highlight the first digit on the display, and
the digit can be changed as required. Press the ENT button to advance to the next digit. When ENT is pressed on the last
digit, the new squawk code or Flight ID will replace the previous value. If the code entry is not completed within 7 seconds
the changes are ignored and the previous code restored
.
List of Common VFR Squawk Codes
1200 VFR code in the USA
7500 Hijack code
7600 Loss of communications
7700 Emergency code
The Call Sign/ Flight ID should correspond to the aircraft call sign entered on flight plan. If no flight plan is active the aircraft
registration should be used as the Call Sign/ Flight ID. Use only letters and digits. If the Call Sign/ Flight ID is less than 8 characters
long entering a blank character will end it.
Copyright © FreeFlight Systems 2011
3700 Interstate 35 S.
Waco, TX 76706-3756
USA
1 (254) 662-0000
FreeFlight FDL-978-TX Transmitter (P/N 85595-00)
Quick Reference Guide
Publication #86963 Rev B
