FM translators when AM parent station is off the air

[Matthew Osborne]

I have a question for the group - if you have an FM translator that repeats an AM primary station, is there any sort of rules about the translator shutting down if the parent station is off the air?  Yesterday I tried sampling the new 'Mix' format on WAIX (AM 1160 Mechanicville NY, with FM translator on 106.1) and was surprised to find that AM 1160 was off the air but the FM translator was not.  I just checked again this morning, and the same scenario holds true (AM off the air, FM on the air).  Isn't there a rule on the books where, if a primary stations goes off the air, any translators must shut down also?

Matthew Osborne
Rotterdam, NY