how do i put a max to rigidbody.AddRelativeTorque

hey im trying to simulate a plane, but when i try to make it rotate it starts to go faster and faster(i know the AddRelativeTorque does that), but i want to add a max and i cant think of a way to do this. here is the code i used:

 @HideInInspector
 var xRotation : float;
 @HideInInspector
 var yRotation : float; 
 @HideInInspector
 var zRotation : float; 
 
 var maxRotation : float = 7;
 var rotSensibility : float = 7;
      
 function Update(){
     
      xRotation = Input.GetAxis("Vertical") * rotSensibility * Time.deltaTime;
      yRotation = Input.GetAxis("Horizontal") * rotSensibility * Time.deltaTime;
      zRotation = Input.GetAxis("Roll") * rotSensibility * Time.deltaTime;
      
      rigidbody.AddRelativeTorque(xRotation, yRotation, zRotation);
      
      if (Input.GetAxis("Horizontal") == 0){
        rigidbody.AddRelativeTorque(xRotation, 0, zRotation);  
      }
      if (Input.GetAxis("Vertical") == 0){
        rigidbody.AddRelativeTorque(0, yRotation, zRotation);
      } 
       if (Input.GetAxis("Vertical") == 0){
        rigidbody.AddRelativeTorque(xRotation, yRotation, 0);
      }
     
     }