B727 CREW DSNDED BELOW MINIMUM ALT OUTSIDE RIDGE IN IMC AT ORD.

Narrative

OUR ACFT WAS BEING VECTORED FOR AN ILS APCH TO RWY 22R AT ORD ARPT. THE WX WAS 7 MI VISIBILITY SCATTERED 1400 FT BROKEN. THE CTLR WAS GIVING ME NUMEROUS HDG; ALT; AND AIRSPD CHANGES WHILE GIVING ME A CLRNC TO INTERCEPT THE ILS FINAL APCH COURSE AT 2200 FT MSL. THE BASE LEG WAS RELATIVELY CLOSE IN TO THE ARPT (9 NM). DURING THE TURN TO FINAL; I BECAME TEMPORARILY OVERLOADED WITH THE NUMEROUS CTLR INSTRUCTIONS AND DSNDED TO APPROX 1700 FT MSL WHILE TURNING TO FINAL APCH. I THEN RECOGNIZED I WAS LOW AND BEGAN A CLB BACK TO THE INTERCEPT ALT. SUPPLEMENTAL INFO FROM ACN 480742: UPON ARR TO APCH ARR; WE WERE CLRED FOR A SHORT VECTOR TO FINAL AND DSCNT FROM 5000 FT TO 2200 FT; GIVEN REDUCTION TO 180 KIAS AND CLRED FOR APCH. CAPT WAS FLYING THE ILS. I WAS ON 113.9 TO HAVE DME FROM FIELD. WHEN WE STARTED OUR DSCNT; CAPT CALLED FOR GEAR DOWN; FINAL DSCNT CHK. I WAS RETURNING CLRNC; USING WX RADAR AND RUNNING CHKLIST WHEN THE CAPT MADE A COMMENT THAT HE HAD LOST THE GS AND WANTED THE LOC MINIMUMS. I COMMENTED THAT 'IT WAS ABOVE HIM;' IMPLYING THE GS -- I STILL HAD 113.9. I THEN SWAPPED TO THE ILS FREQ AND THE CTLR NOTED OUR DSCNT AS WE WERE CORRECTING BACK TO 2200 FT. THE CAPT STARTED DSCNT OUTSIDE THE FAF TO LOC MINIMUMS. WHEN HE PERCEIVED THE GS INOP; NO FLAGS. THE CAPT CLBED BACK TO CLRED ALT WHEN TO CORRECT.