# IOAircraft<no value>
The `IOAircraft` aircraft is a preset of the [WASMAircraft](../wasmaircraft/) **modular aircraft**, which shows three different screens created using the [IO API](../../../../programming-apis/wasm/io-api/io-api/), and each one is focused on a different aspect related to reading and writing files using the API. Once the {{< glossterm >}}wasm{{< /glossterm >}} Aircraft package has been built, this module will be available for flying from the aircraft selection screen:

{{< image-center
    src="images/7_Samples_Tutorials/Samples/WASMAircraft/IOAircraft/io_1_aircraft.png"
    alt="Selecting The IO Aircraft In The Simulation" >}}

The `WasmModules.sln` file (found in the `Sources` folder of the project) will allow you to compile the source-code with Microsoft Visual Studio (2019 or 2022) in order to create the `IOModule.wasm` WebAssembly module which will then be loaded by the simulation. Once compiled, the module will automatically be copied into the following folder:

\[ROOT\]\(PackageSources\)SimObjects\(Airplanes\)MyCompany\_Wasm\_Aircraft\(presets\)mycompany\(IOAircraft\)panel

 

Note that if you make changes to the C++ code and recompile the IO WASM module, you will have to build your package again. This *can* be done while the plane is used within the simulation.

 

 

### Testing

Once you have built the aircraft and selected it, you can go into a **Free Flight** and you will see three panels in the cockpit, looking something like this:

{{< image-center
    src="images/7_Samples_Tutorials/Samples/WASMAircraft/IOAircraft/io_2_screens.png"
    alt="The Cockpit Interior Of The IO Aircraft" >}}

 

These screens illustrate the following:

 

1.  On this screen the value of Pi is displayed. Either as a full value (using the `ALL Pi` button) or in parts (using the `previous` / {{< button "Next" />}} buttons). This value has been read from the `pi.txt` file located in the `Data` folder of the package.  
     
2.  This screen shows how a file can be read from the `work` folder. If the file exists (see screen 3, below), then clicking on the `Read Pi` button will read pi from the copy of the `pi.txt` made in the `work` folder and display it on the screen.  
      
3.  This screen has a single button - `Copy Pi in work/` - which, when clicked, will copy the `pi.txt` file into the aircraft `work` folder. The work folder can be accessed from any {{< glossterm >}}wasm{{< /glossterm >}} module, and in this example it is used by Screen 2 to read from the copied file and display pi.