How do I update NAV data in Prepar3D with Navigraph?

To update NAV data in Prepar3D, close the simulator, use Navigraph FMS Data Manager to detect or manually map each supported aircraft, avionics package or planner, then install the required AIRAC cycle. Restart Prepar3D and verify the cycle on the FMC’s IDENT or STATUS page; this does not normally update Prepar3D’s base navigation data.

Prepar3D users often call this application the Navdata Manager or Navigraph updater. For most Prepar3D-era add-ons, the relevant tool is FMS Data Manager; installing data through another Navigraph application does not prove that a particular P3D aircraft has been updated.

What does a navdata update (aggiornamento navdata) change?

A Navigraph update replaces the separate navigation databases used by supported add-on aircraft and utilities, not every source of navigation information in Prepar3D.

For readers using the Italian term aggiornamento navdata: sì, supported Prepar3D add-ons can be updated, but the simulator’s navigation sources are not all replaced together.

This separation explains why an updated FMC may contain a waypoint or procedure that the default GPS cannot find. Our explanation of simulator navdata layers and AIRAC cycles covers the distinction between aircraft, planning and scenery databases.

AIRAC data is licensed. Use data supplied through an account entitled to that cycle rather than copying packages shared by other users; our guide to legal AIRAC update options explains the legitimate alternatives.

How to run the Prepar3D Navigraph update

The safe method is to map each actual navdata consumer, install one consistent AIRAC cycle and then verify it inside the aircraft.

1. Identify what needs updating. List the aircraft, avionics and planning applications used for the flight. Some related aircraft share one database, while others require separate formats; follow the profile intended for the exact product.
2. Back up user-created data. Preserve custom waypoints and any files you have edited manually. Do not merge individual files from different AIRAC cycles.
3. Close software using the database. Exit Prepar3D, aircraft configuration tools and flight planners. Check that Prepar3D has fully stopped rather than leaving a process or utility running in the background.
4. Open FMS Data Manager. Sign in with an account that has access to the required cycle. Use the application that lists explicit support for your add-on; for most P3D-era formats, that is FMS Data Manager.
5. Scan for installed add-ons. Review every detected entry instead of accepting the list blindly. Confirm the product name, Prepar3D generation and destination path, especially if more than one P3D installation exists.
6. Create missing mappings manually. Select the profile for the exact add-on and point it to the folder expected by that profile. Aircraft installed outside the simulator through an add-on package can escape automatic detection. A mistake we see constantly is mapping the Prepar3D root when the profile expects an aircraft-specific or shared navdata folder.
7. Install the same AIRAC cycle. Update each required mapping and wait for every entry to report completion. A successful update for one aircraft does not update unrelated aircraft or planners.
8. Restart and reload the aircraft. Start a fresh Prepar3D session so the avionics read the replacement database. A panel reload may leave old information cached.

If a product is absent from the manager’s supported profiles, do not force another aircraft’s format into its folder. Use a product-specific manual package only when the add-on’s instructions identify that format and destination.

How do I fix “Error prepping navigation data”?

The Error prepping navigation data message means FMS Data Manager could not prepare, extract or pass the AIRAC package to the selected installation; it does not usually indicate a fault inside the aircraft’s FMC.

1. Close all related applications. Exit Prepar3D and any planner or utility that may be holding navdata files open, then retry only the failed target.
2. Inspect the failed mapping. Remove references to an old drive, another Prepar3D version or a duplicate aircraft installation. Confirm that the destination still exists and belongs to the selected profile.
3. Force a clean download. Discard the failed package through the manager’s available controls and download the cycle again. Do not delete unidentified application folders or copy files from another AIRAC package.
4. Check write access and storage. The Windows temporary location and destination folder must be writable and have enough free space. Read-only folders, controlled-folder protection and security software can prevent extraction or replacement.
5. Check the account and connection. Sign in again if every profile fails before installation. An interrupted download or expired session is more likely when all targets fail at the preparation stage.
6. Retry with elevation only when justified. Administrator mode may help when a correctly mapped add-on sits in a protected folder, but it will not repair a wrong path or unsupported profile.

• Only one profile fails: suspect its mapping, destination permissions or an unsupported installation layout.
• Every profile fails: suspect the downloaded package, temporary folder, account session, security controls or the manager installation itself.
• Preparation succeeds but installation fails: look for a locked destination file, read-only folder or security block.

The manager’s status details or log should identify which target failed. Record that product and path before removing mappings; otherwise it is easy to recreate the same incorrect destination.

How do I verify the installed AIRAC cycle?

The authoritative check is the cycle displayed inside each aircraft, not the updater’s completion message or a Windows file date.

• Open the FMC or FMS IDENT, STATUS or database information page.
• Confirm the four-digit AIRAC identifier and, where shown, its effective dates.
• Load a known SID or STAR and inspect its waypoint sequence.
• Check every separately mapped aircraft and planning tool; they can hold different cycles on the same computer.

The first two digits of a standard four-digit AIRAC identifier represent the year and the final two represent the cycle number. If the aircraft displays dates rather than a cycle code, compare those dates with the cycle selected in FMS Data Manager.

Why does the FMC still show the old cycle?

An FMC that retains its old cycle after a reported update is usually reading a different installation or database path from the one FMS Data Manager changed.

If the cycle is correct but the CDU reports NOT IN DATABASE, reinstalling the same package repeatedly is rarely useful. Follow our diagnosis of FMC “not in database” errors to distinguish a cycle mismatch from a spelling, route or procedure problem.

Can Navigraph update Prepar3D’s default GPS and navaids?

Navigraph does not normally replace the scenery-based facilities used by Prepar3D’s default GPS, map, ATC or built-in Flight Planner.

That is why the built-in planner may produce a different route from an updated add-on FMC. Our guide to the Prepar3D Flight Planner and its navigation source explains what it can use and why its results may disagree with an add-on database.

Airport scenery creates another independent layer. An AIRAC update can give the FMC a renamed runway, revised procedure or changed navaid record while the installed scenery still depicts the older runway number, localiser position or frequency. Keep the aircraft and external planner on the same AIRAC cycle, correct scenery discrepancies separately, and never copy aircraft navdata files into Prepar3D’s scenery folders.