A serious question, what type of airspace is TIBA? I can't seem to find an answer in the AIP. I understand how it works, but does the airspace (say a centre frequency for example) still maintain it's airspace classification when TIBA is in operation? Or does it revert to a lower classification?
There is no change to the 'class' or classification of airpsace subject to TIBA. The change is to the level of service provided in that airspace (i.e. squat all) but the classification doesn't change.