Help with losing WASD control when switching cameras

(Reposting in Help Room after accidentally posting in default and waiting forever for a mod)

Hi guys, as a hobby project I'm making a little biplane shooter. The problem I'm running into is when I switch to the cockpit camera from the 3rd person chase camera I lose the ability to control the plane with wasd, and the frame rate takes a huge dip. The switching is working as intended but I'm open to trying a different approach if I can optimize it in any way. Anyways, here is my code for switching the cameras -

 public class CameraController : MonoBehaviour {
 
     public Camera chaseCamera;
     public Camera firstPersonCamera;
 
 
     void Update () {
         if(Input.GetKeyDown(KeyCode.V)) {
             
             firstPersonCamera.gameObject.active = !firstPersonCamera.gameObject.active;
             chaseCamera.gameObject.active = !firstPersonCamera.gameObject.active;
 
         }
     }
     
     void ShowChaseView () {
         firstPersonCamera.enabled = false;
         chaseCamera.enabled = true;
     }
     
     
     void ShowFirstPersonView () {
         firstPersonCamera.enabled = true;
         chaseCamera.enabled = false;
     }
 }

And here is the plane control script -

 public class PlaneControl : MonoBehaviour {
 
     public float planeSpeed = 80.0f;
 
     
     void Start () {
     
     }
     
     
     void Update () { 
 
         transform.position += transform.forward * Time.deltaTime * planeSpeed;
 
         planeSpeed -= transform.forward.y * Time.deltaTime * 10.0f;
 
         if (planeSpeed <= 30.0f) {
             planeSpeed = 30.0f;
         }
 
         Vector3 moveCamTo = transform.position - transform.forward * 1f + Vector3.up * 5.0f;
         float bias = 0.96f;
         Camera.main.transform.position = Camera.main.transform.position * bias + moveCamTo * (1.0f - bias);
         Camera.main.transform.LookAt(transform.position + transform.forward * 30.0f);
 
         transform.Rotate(Input.GetAxis("Vertical"), 0.0f, -Input.GetAxis("Horizontal"));
 
     }
 }

Any help is really appreciated! I don't understand what would be causing this to not work. And additionally, the camera will sometimes be very far away from the plane and it takes a long time to readjust. How can I set a maximum distance the camera can be away from the plane? Thank you all!!