Unserviceable up to 10 days seems to be the norm. Germany is the one oddball state out there as it allows a maximum of 3 days for all aircraft including overflights. Of course the question is: how can they determine if anyone has their TCAS inop and for how long has it been inop? If one lands in germany however and runs into a SAFA check the aircraft will be grounded until TCAS is repaired.