helicopterdude, TIBA can be a Tower, Terminal Approach Radar or Upper Airspace etc, basically anywhere where ATC provides a control service but its no longer available. Similar to a CTAF but more like flying in Class G.
Picture a chunk of upper airspace (say 45miles to 200 miles from a major airport at FL280 - FL600) that is open 24/7 (a light 'globe' on 24 hours a day) and due to staffing someone just deactivates the airspace - no ATC services (just switches off the light), you can still go in but you'll just be talking to the other jets and some of the Internationals haven't a clue whats going on (blundering through a darkened room?) because its unheard of as a standard international practice.
I'm thinking that the practice is NOT carried out in England, the USA, Canada and mainland Europe despite the Australian regulator's claim that its an inernationally accepted practice with ICAO approval.
Thats the crux of the question...Can ATCers (in the USA, Canada, New Zealand, EU, the British Isles, whereever) confirm what you do if you have controlled airspace that may need to shut due staffing?
Restricted Area (Fly around)?; or,
Uncontrolled (TIBA, fly in at own risk -mself separate)?
Also, how often is the incidence of such airspace 'outages' in your country?
Just a paragraph outlining you knowledge and experiences, For example... I work as an upper air enroute controller in Burkina Faso and the incidence of airpace shutting down is becoming quite regular and averages 3 hours a day and the aispace becomes uncontrolled with no restrictions - enter at own risk and self separate (a few years ago such unsafe and third world safety types of practices were limited to countries like Australia).
Much appreciated!