How to hide nav bar if tabs are showing?

I want to hide the nav bar for a top level tab view.
If tabs are at the top, then hiding the nav bar leaves a space between the top of the screen and the tabs (where the nav bar would normally be).
How do I hide the nav bar and not have that wasted space. ie. move the tabs to the top of the screen when the nav bar is hidden?

Sample is from ionic start app (tabs app). Add hide-nab-bar attribute to tab ion-view element in top level tab views (tab-dash.html, tab-friends.html, etc).

also to tab-chats, tab-accounts.