Enable/Disable Box Bounds

I have an airplane, and a Large cube.
The airplane is inside the cube. I am looking for a script that disables the airplane controller script when you fly outside the cube. Causing it to dead-fall (Ragdoll somehow?)
And if you enter back inside the cube the air plane controller enables again. Sorry I am not much of a programmer, help needed! is it easy?

it is, what you need is this Bounds.Contains check if it is false, and when it is set the YourScriptName.enabled = false, and when it is true to the enabled back to true.

[ EDIT ]

Yes I would apply it to the cube
And the logic would be something like this:

public GameObject planeObject;

private Renderer cubeRenderer;
private YourScriptName myPlaneScript;

void Start()
{
   cubeRenderer = renderer;
   myPlaneScript = planeObject.GetComponent<YourScriptName>();

}

void Update()
{
   // Here you have different ways of coding it, implement one
   // SOLUTION 1: check and then set value
   if(cubeRenderer.bounds.Contains(planeObject.transform.position))
   {
      myPlaneScript.enabled = true;
   }
   else
   {
      myPlaneScript.enabled = false;
   }

   // SOLUTION 2: immediatly assign the value of the check
      myPlaneScript.enabled = cubeRenderer.bounds.Contains(planeObject.transform.position);

}

Or there is a third solution where you would only assign the enabled boolean upon detected change in bounds.Contains.

Having you store the result of you check in another variable to keep track of your previous value. Something like this:

    public GameObject planeObject;
    
    private Renderer cubeRenderer;
    private YourScriptName myPlaneScript;

    private prevPlaneInBounds; // previous Plane In Bounds state
    
    void Start()
    {
       cubeRenderer = renderer;
       myPlaneScript = planeObject.GetComponent<YourScriptName>();
       prevPlaneInBounds = myPlaneScript.enabled;
    }
    
    void Update()
    {

       if(cubeRenderer.bounds.Contains(planeObject.transform.position) != prevPlaneInBounds)
       {
          // if we enter here, the situation of your plane has changed
          prevPlaneInBounds = !prevPlaneInBounds; // so change the bool memory state => This is a shortened version of the logic that would be needed here.
          myPlaneScript.enabled = prevPlaneInBounds; // and apply it to the script
       }
    }