3.4Anonymous Mode
The GDL 88 provides an Anonymous Mode which broadcasts a randomized ICAO address in the ADS-B Out message. The Anonymous Mode, when armed, will replace the Flight ID with a temporary randomized number for privacy while the position information will still be provided. This randomized address allows the ADS-B Out message to not be tied to a specific aircraft, much like a VFR squawk code of 1200 on a Mode A or Mode C transponder. The mode is armed via a switch in the cockpit or via a control on the display integrated with the GDL
88.When a VFR squawk is present in the transponder and anonymous mode is selected, then the GDL 88 operates in anonymous mode and no identifying information is provided in the ADS-B Out message. This mode will persist until the squawk code is changed or the Anonymous Mode control is turned to the off state.
Anonymous Mode is not available when installed in an aircraft with a Mode S transponder.
3.5Air/Ground Determination
If a weight on wheels or squat switch is installed, the GDL 88 will use that input to determine air/ground status. If not, then air/ground status is purely based on GPS-derived information.
190-01122-03 Rev. A | GDL 88 ADS-B Transceiver Pilot’s Guide | 3-3 |