From Longman Dictionary of Contemporary Englishradio beaconˈradio ˌbeacon noun [countable] TTATCa tower that sends out radio signals to help aircraft stay on the correct course
Examples from the Corpus
radio beacon• Then the pilots apparently selected a heading toward another radio beacon near the threshold of runway 19.• The airport has no radar nor instrument landing system and planes are guided in by radio beacon.• Following the crash the airliner's emergency radio beacon failed to function and rescue teams experienced difficulties locating the wreckage. 