andymurph wrote "it seems illogical for the Flight Recorder not to signal it's location in hard to reach terrain."
The Flight Data Recorder (FDR) and Cockpit Voice Recorders (CVR) have attached to them a water-activated Underwater Location Beacon (ULB).
The ULB's do not operate when they are not immersed. They are intended to aid locating the recorder when an aircraft ends up in a lake, sea or ocean. An ultrasonic pinger cannot be detected through the air.
The FDR and CVR are painted a bright fluorescent orange. It was expected that this would be sufficient to enable them to be located among aircraft debris on land.