MDT COMMUTER FLC VECTORED HIGH AND FAST FOR VISUAL 9L AT ORD HAD TCASII RA; OVERSHOT 9L PROCEEDING TO 9R TOO HIGH TO LAND; MADE A GAR MISSED APCH.

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I WAS THE FO AND PF ON A FLT FROM MADISON; WI; TO CHICAGO O'HARE. APCHING CHICAGO FROM THE NW; WE WERE ASSIGNED A PARALLEL VISUAL APCH TO 9L. APCH CTL VECTORED US FOR A CLOSE IN AND VERY HIGH L BASE LEG TO 9L APPROX 8-10 MI FROM ORD AND KEPT US AT 7000. WE RPTED 9L IN SIGHT AND WERE CLRED FOR THE VISUAL APCH. I INITIATED A RAPID DSCNT WITH THE AUTOPLT VERT SPD MODE AND ARMED THE APCH MODE TO INTERCEPT THE LOC. THE ACFT NOSED OVER AND STARTED DSNDING RAPIDLY. THEN; FOR SOME UNKNOWN REASON; THE AUTOPLT AND FLT DIRECTOR MALFUNCTIONED AND SHUT ITSELF OFF. THIS DREW MY ATTN TO INSIDE THE COCKPIT TO SILENCE THE 'AUTOPLT OFF' WARNING AND TAKE CTL MANUALLY. WHEN I AGAIN LOOKED UP TO FIND THE ARPT; RWY 9L WAS OBSCURED BY THE ACFT PILLAR BTWN THE FRONT AND SIDE WINDOWS ON THE L SIDE OF THE COCKPIT AND I MISTOOK RWY 9R; WHICH WAS VISIBLE IN THE FRONT WINDOW; FOR 9L. I BEGAN A BASE TO FINAL TURN TO WHAT I THOUGHT WAS 9L AND KEPT DSNDING UNTIL THE TCASII GAVE A WARNING TO 'CLB'. THE CAPT NOTICED THAT I HAD OVERSHOT FINAL JUST AS THE TCASII BEGAN GIVING AN RA TO 'CLB'. I CORRECTED BACK TO 9L AND LEVELED OFF TO COMPLY WITH THE RA. WE CONTINUED THE APCH. HOWEVER; I WAS TOO HIGH TO LAND ON 9L AND WE DID A GAR. I BELIEVE THAT THE ACFT THAT CAUSED THE RA WAS BELOW THE FLOOR OF THE TCA AND NOT AN IFR ACFT SO NO LOSS OF SEPARATION OCCURRED. HOWEVER; WE DID GO THROUGH THE LOC AND INTO THE FINAL APCH COURSE FOR 9R. I BELIEVE THE CAUSE OF THIS INCIDENT WAS THE AUTOPLT/FLT DIRECTOR FAILURE AT A VERY CRITICAL PHASE OF FLT; THE FLC'S LATE RECOGNITION OF A MISIDENT OF RWYS; AND THE FATIGUE OF THE CREW. WE HAD STARTED OUR DUTY DAY EARLY AND FLOWN 6 LEGS INTO AND OUT OF ORD.