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GRT Nav update

John Owen

Well Known Member
Hello, I bought a RV-7 with a GRT Horizon HXr EFIS and like it a lot. However, I can't get the nav database (free from GRT!) to load. I called them and they gave me some advice about making sure that it is labeled NAV.DAT without parentheses and a number to follow on the thumbdrive. I did that and the EFIS will see it now but when I try to load it, it says that database is too large. I tried cleaning the rest of the thumbdrive and still no joy. It is just what I downloaded from their website and unzipped it.

I can call them again in a few days but have a flight that I hope to make this weekend and they won't be in the office before then. Any help would be appreciated.

Thanks,
John
 
Hello, I bought a RV-7 with a GRT Horizon HXr EFIS and like it a lot. However, I can't get the nav database (free from GRT!) to load. I called them and they gave me some advice about making sure that it is labeled NAV.DAT without parentheses and a number to follow on the thumbdrive. I did that and the EFIS will see it now but when I try to load it, it says that database is too large. I tried cleaning the rest of the thumbdrive and still no joy. It is just what I downloaded from their website and unzipped it.

I can call them again in a few days but have a flight that I hope to make this weekend and they won't be in the office before then. Any help would be appreciated.

Thanks,
John


You stated you unzipped the file. Did you really unzip the .dat file?
 
1. As you said, make sure the file is ‘nav.dat’. If you downloaded it and your computer already had a file with that name the new one will be nav.dat1. You need to drop the 1.
2. File cannot be inside any folders on the thumbdrive.
3. Are you using the original thumb drive from GRT? Not all drives work.
 
HXr displays are pretty unfussy about memory stick brands compared to previous displays. But, as mentioned, verify that the file name and type is correct. If you downloaded a file that had to be unzipped, it's not a NAV.DAT file. GRT has never posted the NAV database files as .ZIP files. The regular NAV file is about 7.2 mb, the version for those with the approach plate option is about 9.2 mb (don't quote me on the exact number but that's close).
 
perhaps a typo? should be NAV.DB

Mine is always named "NAV.DB" - so if you are renaming it or unzipping it that might be causing trouble. It also needs to be in the top level directory, not in a subdirectory.
 
HXr displays are pretty unfussy about memory stick brands compared to previous displays. But, as mentioned, verify that the file name and type is correct. If you downloaded a file that had to be unzipped, it's not a NAV.DAT file. GRT has never posted the NAV database files as .ZIP files. The regular NAV file is about 7.2 mb, the version for those with the approach plate option is about 9.2 mb (don't quote me on the exact number but that's close).

I thought that the website said that it had to be unzipped and just assumed that it had been (by the magic of computers) as it downloaded since it was not a .zip file.

I just checked by redownloading it and it is about 7.4 mb and was able to download it as a .DB file instead of a DAT. I renamed it to get rid of the number, which I had tried before. Now to wait for the outside temps to get into double digits to run out to the airport and see if this will load. I am assuming that going to the maintenance page and checking the nav data line then loading it will work. That is where I tried it on previous attempts that was told that it was too large. It is not really intuitive after previously loading databases in a Garmin but once I get it, I will have it.

Thanks for the help and I will give this good advice a try.

John
 
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