Swift - Navigation Controller

App Delegate
self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
var home: HomeViewController = HomeViewController(nibName: "HomeViewController", bundle: nil)
var nav_ctlr: UINavigationController = UINavigationController(rootViewController: home)
self.window.rootViewController = nav_ctlr
self.window.makeKeyAndVisible()
UIApplication.sharedApplication().statusBarHidden = true
return true


View Controller
@IBAction func Landing(sender: AnyObject)   
{
        let land_vc = LandingViewController(nibName:"LandingViewController", bundle:nil)
        self.navigationController?.pushViewController(land_vc, animated: true)
}