I can call the area that I am flying overs Civil Aviation Authority/ Emergency Management Department. I have manuals, charts etc ... for all the area's that I operate in ( Australia/ New Zeakland / South East Asia, even the US,Canada, South Africa to name a few ). My main contact is our Charter company emergency contact number. They / we keep a database of Emergency contact number for all the areas we operate in. As a last resort I can contact the company that we are chartered by.