With no active transponder MH370 would have been unidentified, and no communication with ATC would make it unannounced. It was also unexpected as there was no '

With no active transponder MH370 would have been unidentified, and no communication with ATC would make it unannounced. It was also unexpected as there was no 'plane due to be in that area according to the filed flight plans (or every other one was identifiable).