G500, G600, and G500H Series products using GDU 620 main software version 6.21.
Flight crews may observe unexpected display issues such as flashing “NO AP DATA” annunciation or intermittent display of the Flight Director cue. The condition can also cause intermittent display issues related to ADF, Weather Radar, and Fast/Slow (PC-12 aircraft only).
These issues can be caused by a fragmented Terrain Database file on the Database Card.
No action is required if the display does not exhibit the issues described above (not all GDU 620 displays are affected).
If the aforementioned issues are observed:
- Crew should closely monitor altitude capture performance if the G500/G600 is used for automatic altitude capture (i.e. altitude preselect).
- Contact Garmin Aviation Service Center or Dealer for a replacement Database Card that is marked MOD 1.