Data Base Invalid - AIRAC Data in iFly 737 NG (P3D)

Hi All,

We are brand new Prepar3D users (version 4) and have purchased the iFly 737NG addon along with the Navigraph Ultimate subscription. However, we cannot seem to get the FMC to recognise the AIRAC data. It appears to be installed correctly:

…but the FMC says DATA BASE INVALID:

Being new users we are a bit unsure whether we have done something wrong in the setup/installation, or whether there is an actual known issue here. Searching the forum we found this post AIRAC 2102 for IFLY NG737 "data base invalid" message on FMC which seems related (albeit on FSX rather than P3D) but that looks like it was fixed.

Any help would be greatly appreciated.

Hi All,

We’ve managed to fix the issue, and it had nothing to do with the Navigraph data.

While not strictly related to Navigraph, for the benefit of others who may have this problem, here’s our solution. We noticed that after the initial installation of the iFly 737 package there was some default AIRAC data installed (from 2013) and even that did not work, indicating the problem was probably with the add-on itself. After reading some posts on their support forum we had to give full read/write access to the Lockheed Martin folder.

To do this, right click on the C:\Program Files\Lockheed Martin folder and select “Properties”. Click the “Security” tab and the “Edit” button. Click “Add” and type “Everyone” in the text box and then click “Check Names” and OK. Select “Everyone” in the list and make sure that “Write” is ticked in the permissions (in addition to Read, List folder contents, and Read & execute).

Click OK then OK again and it will apply those permissions to everything in the Lockheed Martin folder. We then found that the FMC could read the AIRAC data.

Probably not the best in terms of security, but it works.


Thank you for the update. Glad it is resolved.


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