CAPT OF AN LTT TURBOPROP FAILED TO FOLLOW THE PRESCRIBED LOC COURSE WHEN DSNDING IN RAIN AT NIGHT ON AN ILS APCH RESULTING IN THE ATC INTERVENTION TO DIRECT HIM TO CLB IF THE FIELD WAS NOT IN SIGHT. THE CAPT CONTINUED TO DSND AFTER BEING TOLD BY ATC; AND THE FO; TO CLB AND SUBSEQUENTLY BROKE OUT OF THE OVCST; SIGHTED THE ARPT AND LANDED SUCCESSFULLY.

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ON APCH INTO CAK; WE REALIZED WE WERE NOT GOING TO BE ABLE TO COMPLETE A VISUAL APCH DUE TO A LAYER AROUND 2000 FT MSL. WE ASKED FOR VECTORS FOR THE APCH AND RECEIVED A HDG. THE CAPT OVERSHOT THE TURN TO FINAL BECAUSE OF TOO MUCH AIRSPD. HE TOOK THE 'CUT' BACK TO THE LOC AS ASSIGNED; BUT IT WASN'T ENOUGH. THE GS CAME ALIVE AND HE BEGAN FOLLOWING IT WITH THE LOC STILL DEFLECTED FULL SCALE. I KEPT WATCHING FOR IT TO COME ALIVE; BUT IT HAD NOT. AT THIS TIME; CAK APCH (IT MAY HAVE BEEN TWR) TOLD US WHERE THE FIELD WAS AND ASKED IF WE HAD IT. THE CAPT WAS STILL DSNDING AND TOLD ME HE WAS LOOKING. APCH CALLED BACK AND SAID IF WE DID NOT HAVE THE FIELD TO 'CLB TO 3000 FT NOW.' I DIDN'T RESPOND TO ATC BUT ASKED THE CAPT TO CLB. HE WAS STILL DSNDING AND LOOKING; STILL NOT ON THE LOC (BUT FOLLOWING THE GLIDE PATH). ATC CALLED BACK AGAIN; TELLING US TO CLB AND ASKING IF WE HEARD THEM. AT THAT TIME THE CAPT FOUND THE FIELD; I CALLED ATC; AND HE LINED UP FOR THE APCH (STILL DSNDING OVER THE CITY). I FEEL THAT THE PROB BEGAN WHEN THE CAPT DID NOT SLOW TO THE ACCEPTED INTERCEPT SPD AND OVERSHOT THE TURN ON THE LOC. HE THEN SAW THE GS AND DECIDED TO FOLLOW IT. WE DISCUSSED LATER THAT WE KNEW IT WAS 'UNPROTECTED' AIRSPACE. I FEEL THAT I SHOULD HAVE BEEN MORE FORCEFUL WHEN HE BEGAN THE DSCNT AND THEN LATER WHEN GIVEN MISSED APCH INSTRUCTIONS. DUE TO THE FACT THAT THE CAPT HAS THOUSANDS OF HRS MORE THAN ME; I MAY HAVE BEEN SLOW TO SPEAK (YOUTH AND INEXPERIENCE).