SMT DSNDS BELOW GS WHEN GS RECEIVED PROB IS NOT RECOGNIZED.

Narrative

FO SET UP LOC BUT FAILED TO REMOVE DME (SET TO VOR) FROM 'HOLD.' LORAN SET TO VOR INSTEAD OF ARPT. THESE 2 THINGS GAVE ME THE FALSE INDICATIONS OF DISTANCE FROM ARPT (I THOUGHT I WAS CLOSER THAN I WAS). FO CALLED 'GS ALIVE;' THEN ' ON GS.' MY INSTS GAVE NO INDICATION OF GS. I CALLED APCH AND ASKED IF GS WAS WORKING. APCH SAID 'WE'LL CHK.' I NEVER RECEIVED CONFIRMATION OF GS WORKING FROM APCH. I HAD RECEIVED AN EARLIER 'LOW ALT ALERT' BUT IGNORED IT BECAUSE I WAS LEVEL AT 2200 FT; BUT HAD BEEN DSNDING AT OVER 2000 FPM. I RECEIVED A SECOND WARNING AFTER I BEGAN ATTEMPTING TO TRACK FO'S GS NEEDLE; THEN CALLED FOR 'LOC ONLY' MINIMUMS. APCH NOW ISSUED A SECOND 'LOW ALT' ALERT WARNING AND A REQUEST TO MAINTAIN 2200 FT. AS I BEGAN A CLB TO 2200 FROM 1700; MY GS 'CAME ALIVE.' AT INTERCEPT; WE CONTINUED THE APCH WITHOUT INCIDENT. HUMAN FACTORS: FO; AND I TOO; WERE TIRED FROM AN UNUSUAL 14 HR DAY; THE DAY BEFORE. FO IS A 'NIGHT PERSON' AND DOESN'T ALWAYS FUNCTION WELL EARLY. FO FAILED TO RECOGNIZE HER GS INDICATOR WAS 'FLAGGED.' CAPT DIDN'T BRIEF APCH AS WELL AS I SHOULD HAVE. CAPT DIDN'T MONITOR APCH BEING SET UP. BOTH OF US -- FATIGUE; BAD WX; AND LAST MINUTE DEP CHANGES FROM ONE ARPT TO ANOTHER. SUPPLEMENTAL INFO FROM ACN 240490: HE THEN HAD ME TUNE THE #2 NAV RADIO TO CAPITAL VOR (WHICH WAS THE OM) AND THEN HE SET THE DME HOLD BUTTON FOR NAV 2 RADIO. THE PIC ASKED IF MY HSI HAD AN 'OFF' FLAG ON THE GS. I SAID NO. HE THEN ASKED WHAT GS INTERCEPT WAS FOR THE FINAL APCH FIX. '2163' FT SAID. I ASSUMED WE WERE AT THE FINAL APCH FIX BASED ON GS INFO.