LANDED AT THE WRONG ARPT. DEPARTED WITHOUT A DISPATCH RELEASE.

Narrative

ARPT OF INTENDED LNDG WAS FAYETTEVILLE; AR. CAPT CANCELLED IFR; FLEW CLOSE IN PATTERN AT NIGHT AND LANDED AT SPRINGDALE MUNI ARPT. I (F/O) RECOMMENDED GO AROUND WHEN NUMBERS 18 INSTEAD OF 16 RWY APPEARED; BUT CAPT INSISTED ON LNDG. THEN; I RECOMMENDED WE NOT TKOF W/O CHKING WITH COMPANY; BUT CAPT TOOK OFF W/O COMPANY FLT RELEASE. SUPPLEMENTAL INFORMATION FROM ACN 81353: AT THIS TIME WE WERE DSNDING THROUGH APPROX 3800' AND WOULD BE LOSING RADAR CONTACT WITH MEM; SO WE CANCELLED IFR AND WERE CLRD OFF OF THE FREQ THOUGH WE CONTINUED TO MONITOR MEM AND 118.5 BOTH. AS I STILL HAD NOT SPOTTED THE ARPT THE F/O POINTED IT OUT TO ME AS SOON AS COM WITH MEM WAS COMPLETE. IT LOOKED LIKE IT WAS IN THE CORRECT LOCATION AND THE SURROUNDINGS LOOKED LIKE I REMEMBERED THEM FROM MY LAST TRIP 1 1/2 YRS BEFORE. UPON REVIEW OF THE WHOLE CASE AND LATER LOOKING AT CHARTS FOR H37; WHICH WE DID NOT HAVE ON BOARD AT THE TIME OF THE INCIDENT; WE NOTICED THE LOC FREQ FOR H37 IS 110.9 AND FYV IS 111.9. IF THE PROPER FREQ WAS TUNED THERE IS NO WAY IT COULD HAVE CENTERED. THE F/O HAD TURNED BOTH RADIOS TO THE SAME FREQ; BUT AS IT WAS A CLEAR NIGHT AND WE WERE USING THE LOC FOR A BACK-UP ONLY; HE HAD NOT BOTHERED TO IDENTIFY IT WITH THE CODE. NEXT TIME IT WAS BE THE FULL APCH REGARDLESS OF WX.