Previous Next Contents

2. Database Questions

2.1 Where can I get a free database with coverage outside the USA?

Thomas Wimmer has compiled fplan database files for Austria and Germany. At this time, fplan compatible database files are not available for other countries. However, the next release of avdbtools will provide support for Digital Aeronautical Flight Information Files (DAFIF), available from the US National Imagery and Mapping Agency (NIMA). These files were once available by CD-ROM on a subscription basis only, but are now available for download by FTP at no charge. The DAFIF database files include information for many major airports outside the United States.

Another possible approach is to construct a small personal database of your own using information from other sources. See the fplan user's guide for information on how to construct your own database files. One source of information for such a personal database can be obtained from the Worldwide Airport Path Finder hosted by Falling Rain Genomics, Inc. It should be emphasized that the data at this site is not certified for navigation, but it could serve as a reasonable starting point for users that are willing to do their own data validation. Their site can be found at;

2.2 Why can't I access the National Flight Data Center web site?

Unfortunately, the US National Airspace Data is no longer available for free download over the Internet. As of August 1999, a password is required to access the NFDC ftp and web sites, and is limited to those who have paid for the NASD subscription plan. See the following FAQ for more information.

2.3 How can I order the US National Airspace Data CD-ROM?

The US National Airspace Data ISO 9660 CD-ROM can be obtained for a nominal fee by sending a request in writing to the FAA Aeronautical Information Services Division. The data is suitable for navigation purposes, and the effective dates coincide with the 56 day charting cycle. The data is generally available about 15 days before the starting effective date. A subscription plan is also available that includes ftp access, and a four month advance notice of format changes. More information can be obtained from the FAA AIS web sites at;

2.4 Why isn't airport or navaid XYZ in your stupid database?

It's possible that you are using the wrong identifier. Don't forget that the fplan airport database uses the "K" convention. You've probably heard of it if you own a GPS receiver. It's basically a mechanism designed to deal with the fact that there are airports and navaids out there with the same identifier. For an airport with an identifier that is 3 alphabetic characters long, simply prefix it with the "K" character. (Do this regardless of whether there is a navigational aid with the same identifier or not). If it contains numeric characters, or is not exactly 3 characters long, don't prefix it with the "K" character. For example, HMT becomes KHMT, L78 remains L78, and CL35 remains CL35. Remember that you can use the lookup mode to get a summary of information in the database for any given identifier (using the -l option).

The freely database for the USA is available in two flavors. The complete version that contains all airports, both public and private usage, and a version with only public usage airports (although they could still be privately owned). If you downloaded the smaller public database, it's possible the airport in question is for private usage only.

2.5 I get an error message saying fplan can't find the databases?

Most likely, it's because you installed the database files somewhere other than where fplan is looking for them. The default directory under UNIX is /usr/share/fplan. If you built fplan from source, examine config.h and Makefile to determine the value of the macro DEFAULT_COMMON_DBDIR. Compare this with where you installed the database files. Also, verify that the database files have read permission. Another solution is to set the FPLAN_COMMON_DBDIR environment variable to reflect where you actually put the files. The best place to do this is in the initialization file for your command shell, the ~/.cshrc for C shell users, or the ~/.profile for Bourne shell users.

Previous Next Contents