Navdata

NextATC uses X-Plane airport data and optional navigation data for fixes, navaids, airways, SIDs and STARs.

The plugin can still fly without a matching SID or STAR. Updated navdata gives better procedure coverage and fewer missing-fix cases.

Navdata source priority:

1. X-Plane/Resources/plugins/NextATC/navdata/
2. X-Plane Custom Data/
3. X-Plane Resources/default data/

When the plugin navdata folder is missing, NextATC falls back to the same native X-Plane navdata layout used by the simulator. The OSD reports when an X-Plane fallback source is active. If the detected AIRAC cycle is older than the current cycle, the navdata lines are shown as an amber warning.

Navigraph API Download#

Direct Navigraph API download is available from Options -> Navigraph Navdata. If you have an active Navigraph navdata subscription, NextATC can download and install navdata automatically. You can also enable Download navdata at startup after the first login.

How it works:

1. Press Connect Navigraph.
2. Open the Navigraph browser page shown by the plugin. When possible, the plugin opens it automatically.
3. Sign in with your normal Navigraph account and approve the device code.
4. Press Download Now to start the download.
5. NextATC fetches the package list, downloads the signed ZIP, verifies its SHA-256 hash when provided, extracts it, validates the X-Plane native navdata layout and installs it into the plugin Navdata folder.

After the first approval, the plugin stores the Navigraph refresh token in navigraph_auth.ini in obfuscated form and uses it for later downloads. The token is local to this plugin installation and can be deleted with Reset Navigraph Login.

Startup download requires a saved Navigraph login. If the login is reset, the startup download option is turned off until you connect again.

Manual Install Path#

You can also install navdata manually here:

X-Plane/Resources/plugins/NextATC/navdata/

The expected layout is:

X-Plane/
  Resources/
    plugins/
      NextATC/
        navdata/
          earth_nav.dat
          earth_fix.dat
          earth_awy.dat
          CIFP/
            LEBL.dat
            LOWI.dat
            ...

For a dedicated NextATC install, the folder must be named exactly Navdata and live under the plugin folder shown above. If that folder is not present, the plugin automatically uses X-Plane Custom Data and then Resources/default data as fallback sources.

Updating Navdata#

For a manual file replacement, close X-Plane first. The integrated Navigraph downloader manages its own download and reload workflow; see the section above.

Use one complete AIRAC cycle at a time. Replace the whole Navdata folder rather than mixing files from different cycles.

After updating, restart X-Plane or reload the plugin. On startup, NextATC reads the active source:

navdata/earth_nav.dat
navdata/earth_fix.dat
navdata/earth_awy.dat
navdata/CIFP/

For X-Plane fallback sources, the same files are read from Custom Data/ or Resources/default data/.

How To Check It Loaded#

Open X-Plane/Log.txt and search for:

earth_nav.dat version
earth_fix.dat version
reading earth_nav.dat

If plugin navdata is missing but X-Plane navdata is available, the plugin shows the active X-Plane fallback source instead of a red missing-navdata warning. If no usable source exists, SID/STAR selection may be limited. Normal ATC, vectors and direct routes can still work.

Common Problems#

No SID/STAR for a runway:

• The selected runway may not have a published procedure.
• Your first or last enroute fix may not connect to the procedure.
• The installed AIRAC cycle may be old or incomplete.

Procedure exists but looks greyed out:

• Your cruise altitude may be outside the procedure restrictions.
• Respect SIDs and STARs restrictions may make the procedure not recommended for the filed level.

Use Don't use SID or Don't use STAR when needed. NextATC will build fallback departure, vector or approach geometry.