UINavigationBar stretch

I am using default navigationBar with large title and searchBar in navigation item. The problem I am having is when the tableView is scrolled down to see the refreshControl, then navigationBar also increases its height which i want to avoid.

So here is my setup

NavigationController with RootViewController

• This contains Container View with following navigation bar and two controllers -
  1. NavigationBar with
     • Large Titles
     • Search Controller inside Navigationitem
  2. ViewController(VC1) has
     • TableView
       • Refresh View Controll added into table view
  3. ViewController(VC2) has
     • TableView
       • Refresh View Controll added into table view
• Selecting cell from either of the TablView push another ViewController(VC3) which has -
  • Inferred NavigationBar with
    • Large Titles
    • Search Controller inside Navigationitem
  • Table View
    • Refresh control added into TableView

My problem statement is -

When I pull down table view in VC3, navigation bar height also increases which I dont want to.