# ![](favicon-64x64.png) Building a custom missions file

On reading the Aerofly FS 4 `main.mcf`, a few conversions and assumptions are made:

- The **title** will be inferred from your current flight plan. You may supply your own title via CLI parameter (see below), or edit the title in the generated text file.  
  Be aware that your title should not be longer than 32 characters.
- The **description** will be inferred from your current flight plan. You may supply your own description via CLI parameter (see below), or edit the description in the generated text file.  
  Be aware that your description should not be longer than 8 lines of 50 characters each. The description allows for line breaks.  
  The auto-generated description contains information about the IFR/VFR state, time of day, as well as navigational aids in your flight plan.
- You may want to supply an **ILS frequency** for your destination airport. As this cannot be read from the `main.mcf`, you will have to supply this using the ILS parameter (see below).
- As the **initial orientation** of your aircraft cannot be read from the `main.mcf`, you will have to supply a direction manually to the tool (see below).
- As there is no information available about the Aerofly FS 4 magnetic model, you will have to set the **magnetic declination** manually:  
  Check the _true_ direction your aircraft is pointing to. Subtract the _magnetic_ direction to get the magnetic declination.
- If the **position of your aircraft** as given in the `main.mcf` is not close enough to your flight plan origin, the position and direction of your aircraft gets set to the first checkpoint in your flight plan.
- As the custom missions contain less information about **clouds**, this tool will find the lowest clouds and add these to your custom missions file.
- The **ICAO callsign** of your aircraft will be set to match a registration visible in Aerofly FS 4.

## Parameters

```
Usage: nodejs index.js [PARAMETERS...]

Parameters:
  -s, --source       Location of the main.mcf
  -t, --target       Location of your target file
      --title        Title of your mission
      --description  Description of your mission; line breaks allowed
  -i, --ils          ILS frequency like '123.45'
  -d, --direction    Initial orientation of aircraft
      --magnetic     Magnetic declination used for waypoints
      --import       Location of an optional TMC, FPL, PLN, FMS or GPX file

Switches:
  -m  --mission-only Do not export mission list with a single mission,
                     but add mission to already existing file
      --flightplan   Output flightplan
      --skyvector    Output Sky Vector URL
      --geo-json     Save GeoJSON file
      --markdown     Save Markdown file
      --help         This help
```

This tool may also output a [flight plan](flightplan.md).

## Manual editing

As the generated file is a text file, it can be edited with any kind of text editor. You _will_ have to use manual editing to stitch together a mission file for multiple missions.

## Redistribution

If you want to redistribute your mission file, you may want to include [these generic installation instructions](./generic-installation.md).

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