AN ACR ACFT APCHING DTW BRIEFED RWY 22L AS PER ATIS. ATC ASSIGNED 22R AT 18 NM AND CREW DID NOT CHANGE THE FMS APCH SETUP. TOWER DIRECTED A GAR FOR A SECOND APCH.

Narrative

WE WERE ARRIVING AT DTW AND AFTER PICKING UP ATIS WE WERE EXPECTING VECTORS ILS RWY 22L. WHEN CHKING ON WITH APCH WE WERE TOLD EXPECT ILS RWY 22R. WE BRIEFED FOR THE NEW RWY; AND SET UP FOR THE NEW APCH. SOMEWHERE ALONG THE LINES OF BRIEFING; SETTING UP AND ACCEPTING VECTORS WE MISSED CHANGING THE APCH IN THE FMS TO REFLECT THE NEW RWY OF RWY 22R. ONCE WE WERE CLRED FOR THE APCH WE WERE GOING TO INTERCEPT VIA THE FMS BECAUSE AT THAT TIME WE WERE ABOUT 18 MI OUT ON APCH. WE THEN GOT HANDED OFF TO TWR AND BEFORE CHKING IN I NOTICED THAT WE WERE INTERCEPTING ILS RWY 22L ON THE FMS. UPON CHKING IN WITH TWR I TOLD THEM THAT WE WERE CORRECTING BACK ON TO COURSE FOR ILS RWY 22R. THEY TOLD US TO TURN TO HDG OF 265 DEGS TO REINTERCEPT. WE COMPLIED BUT THAT WAS TOO STEEP OF AN ANGLE TO REINTERCEPT THE ILS AND WHEN WE WENT THROUGH TO THE OTHER SIDE OF THE LOC TWR AGAIN QUESTIONED US. I TOLD HIM THAT WE HAD IN FACT INTERCEPTED THE LOC; AND THE AUTOPLT WAS BRINGING US BACK ON COURSE. HE THEN TOLD US TO BREAK OFF AND CONTACT APCH; WHICH WE DID. APCH GAVE US VECTORS TO JOIN AGAIN; WHICH WE DID WITHOUT FURTHER INCIDENT. THE MAIN FACTOR IN THIS INCIDENT WAS NOT GETTING THE FMS SET UP AGAIN AFTER CHANGING OUR EXPECTED RWY. HAD THIS BEEN DONE; EVERYTHING WOULD HAVE GONE AS PLANNED. A CONTRIBUTING FACTOR WAS TWR'S 45 DEG VECTOR TO REINTERCEPT THE LOC. THIS WAS TOO STEEP FOR US TO DO AT APPROX 10-15 MI OUT. THE LOC WENT FROM FULL R TO FULL L DEFLECTION IN A MATTER OF MOMENTS. THE AUTOPLT CAPTURED IT; BUT STILL OVERSHOT. I DON'T THINK HAND FLYING IT WOULD HAVE BEEN ANY BETTER. THERE WERE NO TCAS ADVISORIES ALTHOUGH THERE WERE OTHER ACFT ON APCH ON RWY 22L THEY WERE STAGGERED. IN THE FUTURE I WILL BE MORE PROACTIVE IN MAKING SURE THAT RIGHT PROC IS IN THE FMS.