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4. Additional Information

4.1 Code History

Although this software retains the name fplan, it is a derivative of the original work of Steve Tynor. His last public release was version 1.3, which was posted to volume 30 of the USENET newsgroup, comp.sources.misc in 1992.

I've been using fplan to prepare flight plans since release 1.2, so I've had the opportunity to use it in practice and formulate some ideas for possible improvements. The unusual El Niño driven rains we experienced in San Diego during the first few months of 1998 are largely responsible for this effort. One rain soaked weekend in Jan I decided to implement some of the improvements from my own want list (as a flimsy substitute for actually getting my feet off the ground). I later contacted Steve Tynor with these changes. He indicated he was busy with other things and was no longer actively maintaining fplan. I decided to expand the scope of my improvements enough to get things back to a point where more pilots will be inclined to use it again and contribute to further development of it. The name fplan was retained with Steve's blessing.

4.2 Future Plans

Graphical User Interface

Planning and preparations for a graphical user interface for fplan have begun. This will let users construct, load, and save planfiles using a point and click interface. Michael K. Johnson <> has started this effort by writing an implementation of the graphical previewer based on the Gnome, Gtk+, Glib libraries. Michael quickly convinced me that the Gnome environment would be the best choice for further development of a GUI interface, and fplan is now officially part of the Gnome Project. As a result, the fplan project now has a CVS repository to facilitate development by multiple programmers (also see Mailing List below). A final product is not due for awhile, the fplan internal data structures will require some extensive modifications before work can proceed.

Planning from Digital Charts

Some of the currently available commercial flight planning programs provide a GUI interface that allows you to point and click on the desired flight waypoints from a "sectional quality" chart display. Of course, I agree with those who think this is a very desirable feature. However, any digital chart (hybrid raster and vector) that could be assembled from data currently available from government sources would be inferior to hardcopy NOAA Sectional Charts. (This is consistent with the observation that the cost of digital chart updates from these commercial offerings range from kinda, to really expensive). Hopefully, NOAA will someday release their charts in a digital form at prices comparable with current hardcopy charts (and using data formats that are open to the public). When good quality digital charts become a reality, I will become motivated to develop a similar GUI front end for fplan. You can get the current status of efforts in this area from the NOAA Office of Aeronautical Charting and Cartography web site at

Interfacing with GPS Units

Of the other possible fplan improvements I've thought of, the one that most interests me is a better interface with GPS receivers. I suspect that most other pilots who have GPS capability are like myself. I prefer using it over VORs because of the accuracy, the flexibility and freedom it offers in constructing a flight route, as well as the reduced cockpit work loads. (At the same time I'm quite wary of the planned decommission of the VOR system. It's important to have a back up system available if possible).

Systems like GPS and INS have a unique set of problems when it comes to human factors. Incorrectly entering a waypoint can be the start of much bigger problems. The ability to generate a waypoint or route file (in a format such that it can be uploaded directly to your GPS receiver) from an fplan route would be a very nifty capability. There is already an abundance of freely distributable programs for uploading and downloading route and waypoint files to many popular GPS units.

4.3 Mailing List

The Gnome Project now hosts a mailing list for fplan developers. The list is intended to provide a forum for the discussion of fplan development tasks and design issues. The list is open to all who would like to participate in fplan development, contribute ideas or suggestions, or simply lurk to keep track of where things are going. To join the list, send a mail message with the subject "subscribe" and an empty body to

4.4 Other Software


The databases distributed with fplan were created using the avdbtools package (short for aviation database tools). The package is a collection of software designed to assist in creating and maintaining databases for aviation applications. As of this release, avdbtools consists of a single application that reads the databases distributed by the (United States) National Flight Data Center, and converts them into formats usable by other aviation related applications (fplan and ICAO map to be specific). More information can be found on the avdbtools page at

4.5 Acknowledgements


Michael K. Johnson <> contributed the implementation of the graphical previewer based on the Gnome, Gtk+, Glib libraries. He is also working on a configurable, template based Postscript(tm) format output for flight plans.

Other Acknowledgements

I want to thank Steve Tynor for authoring fplan and making it freely available for everyone to use and enjoy. The high quality of his work made it easy for me to gain a level of understanding of the fplan internals sufficient to make changes and improvements of my own. I also want to extend my gracious thanks to both and the University of North Carolina at Chapel Hill for providing space on their web server for the fplan home page.

4.6 Contacting the Author

If you find a bug in this software (especially if you also have a patch for it) you can contact me by electronic mail at <>. Questions, comments, or suggestions are welcome. I respond to all my e-mail, but please remember, this is a free software project and I do prefer flying real aircraft over playing with my computer, so don't be alarmed if you don't get an immediate reply.

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