function OnTriggerEnter (col : Collider)
{
   DoStuff();
}


function DoStuff()
        { 
              animation.Play("heli")
              camera.main.active = false; 
              yield WaitForSeconds (AnimationLength);
              camera.main.active = true; 
        }

I have written a script to switch between any no of camera's

/****************************

***************************** ***************************** 1. Attach this script to any game object 2. In the inspector window set the no of camera's you have in Camera's Variable 3. Drag the camera's game objects and you are done ***************************** ***************************** *****************************/

var cameras:GameObject[];

private var camId:int = 0;

function Update () { if(Input.GetKeyDown("c")){ switchCamera(); } }

function switchCamera(){ camId++; if(camId < cameras.Length){ cameras[camId-1].gameObject.active = false; } else{ camId = 0; cameras[cameras.Length-1].gameObject.active = false; } cameras[camId].gameObject.active = true; }