How exactly do Helicopters work with the TC?

I would like to make a heli base but I know very little about the dos and don'ts of TC privilege and want to be sure I am doing it right. It's my understanding that if Player A makes a base, adds a TC and then Player B authorises it, Player A can engage the helicopter without it shooting rockets as long as he has no authorisation and as long as Player B is not seen by the helicopter near the base.

Is this correct? Would anything change if Player A did authorise on it at some point but it was changed back to how it should be before engaging the helicopter (e.g re-building parts of the base after a fight and then using the same character to fight the heli later on)?