WRONG ARPT LNDG AT TOP; KS.

Narrative

I WAS THE PF; ON MY FIRST DAY OF LINE OPS AFTER IOE. WE WERE ESTABLISHED ON THE FINAL APCH COURSE INBOUND TO FORBES FIELD (FOE) FOR THE VOR RWY 21 APCH. WHILE DSNDING THROUGH APPROX 2700 FT; WE BROKE OUT OF THE CLOUDS AND THE CAPT RPTED THAT HE HAD THE FIELD IN SIGHT. HE THEN ASKED ME IF I HAD THE FIELD IN SIGHT AT MY APPROX 12-12:30 O'CLOCK POS. I LOOKED UP AND SAW AN ARPT AT MY 12:30 O'CLOCK POS; HAVING IDENTICAL RWY ALIGNMENTS AS MY INTENDED ARPT. I THEN PROCEEDED TO CONTINUE VISUALLY TO THE RWY AND MADE A VISUAL LNDG. AFTER LNDG; AND FINDING SOME UNFAMILIAR ARPT FEATURES; THE CAPT REALIZED OUR MISTAKE; THAT WE HAD LANDED AT BILLARD MUNICIPAL; INSTEAD OF FORBES FIELD. BILLARD IS RIGHT ALONG THE FINAL APCH COURSE OF RWY 21 OF FORBES FIELD; APPROX 5 MI NE OF THE APCH END; AND HAS NEARLY IDENTICAL RWY FEATURES; SUCH AS ALIGNMENT; DISPLACED THRESHOLD; ETC. WE SUBSEQUENTLY OBTAINED NEW RELEASES TO OUR INTENDED DEST. SUPPLEMENTAL INFO FROM ACN 489981: FACTORS THAT CONTRIBUTED TO LNDG AT TOP. THE CLOSE PROX OF THE 2 ARPTS. WX. ARPT DIAGRAMS ARE ALMOST IDENTICAL. BECAUSE OF THE SIMILARITIES; WHAT I SAW APPEARED TO MATCH THE APCH PLATE AND THE ARPT DIAGRAM. I SAW AN ARPT BELIEVING IT WAS FORBES FIELD. FLYING WITH A NEW FO JUST OFF OF IOE. A MAJOR CHK AND BAL WAS NOT AVAILABLE.