The popular website SimBrief can provide you with comprehensive flight documentation for simulations. It gives you the option to download your flight plan as a Google Earth .kml file, but no option to download a FlightGear flight plan.

This tool allows you transform this .kml file into a .fgfp, a FlightGear flight plan.

To install this application you will need to have cargo from the Rust language. If you don't have it, you can refer to the installation instructions here.

Then you simply run the following command in your terminal:

$ cargo install kml_to_fgfp

The binary will, for now, need at least two arguments:

• The first argument refers to the source file, expected to be a .kml file.

• The second argument refers to the destination file, meaning the generated .fgfp file.

  Keep in mind that if the .fgfp file already exists, it will be overwritten.

Here's an example:

$ kml_to_fgfp YSSYSAEZ.kml YSSYSAEZ.fgfp

Don't worry if you don't see output in your terminal, that's the expected behavior.

You can also specify the departure and destination airports, which will complete the flight plan with the airport waypoints:

$ kml_to_fgfp YSSYSAEZ.kml YSSYSAEZ.fgfp YSSY/34L SAEZ/11

The program can output a warning when it detects invalid data in the .kml file (maybe it was manually edited and there's a mistake).

$ kml_to_fgfp YSSYSAEZ.kml YSSYSAEZ.fgfp
Dropping ARSOT waypoint: invalid float literal

In this example, the program will not generate a waypoint for the ARSOT navaid because it found an error in the data.

There's also a help menu that can be accessed with the --help and -h arguments.

$ kml_to_fgfp --help
Usage:
      kml_to_fgfp INPUT OUTPUT [DEPARTURE_AIRPORT] [DESTINATION AIRPORT]

INPUT is the Google Earth (.kml) file.

OUTPUT is the name of the generated FlightGear flight plan (.fgfp) file.

[DEPARTURE_AIRPORT] is an optional argument detailing the departure airport's
ICAO designation. It would look something like `YSSY`. You can also type a `/`
to add a specific runway, so it would look like `YSSY/34L`.

[DESTINATION_AIRPORT] is an optional argument detailing the destination
airport's ICAO designation. It would look something like `SAEZ`. You can also
type a `/` to add a specific runway, so it would look like `SAEZ/11`.

Version: 0.1.0, MIT License

1. Create an EventWriter, it will be used to write to the output file.

   let mut output_file = File::create(output_filepath)?;
   let mut writer = EmitterConfig::new()
       .perform_indent(true)
       .create_writer(&mut output_file);

2. Write the beginning of the .fgfp xml tree using the write_start_of_tree function.

   kml_to_fgfp::write_start_of_tree(&mut writer)?;

3. Create 2 Option<kml_to_fgfp::Airport> setting the value to None if no departure or no destination airports are in the flight plan.

   Then call the write_airports function, passing the previous options as arguments.

   let departure = kml_to_fgfp::Airport {
       ident: String::from("YSSY"),
       runway: Some(String::from("34L")),
   };
   
   let destination = kml_to_fgfp::Airport {
       ident: String::from("SAEZ"),
       runway: Some(String::from("11")),
   };
   
   kml_to_fgfp::write_airports(&mut writer, &departure, &destination)?;

4. Create an EventReader, it will be used to read the .kml file.

   let input_file = File::open(input_filepath)?;
   let input_file = BufReader::new(input_file);
   let parser = EventReader::new(input_file);

5. Call the transform_route function, which will need the xml EventReader, EventWriter, and 2 airport options. This function creates the .fgfp's route using waypoints with the information in the .kml file.

   kml_to_fgfp::transform_route(
       parser,
       &mut writer,
       &departure,
       &destination,
   )?;

6. Close the xml tree by calling the close_tree function.

   kml_to_fgfp::close_tree(&mut writer)?;

If you want an example you can refer to the run function in the runner module.

This program and this repository are available under an MIT License.