Narrative:

Ord wind was 020 degrees at 27 KTS gusting to 35 KTS; the arrival confign was runways 10/9R and 4R. Numerous aircraft were executing missed approachs due to xwinds in excess of 29 KTS. The runway confign was then changed to runway 4R and runway 4L. Problem #1: the dump zones listed on the system; indicated that C90 would utilize an east/west split; runway 4R as the low side and runway 4L the high side. Problem #2: the runway 4R approach plates have a 5000 ft crossing fix (harrl) and the runway 4L approach plates only have a 3600 ft crossing fix (kirby). This would indicate a C90 north/south split and runway 4R as the high side and runway 4L the low side. Problem #3: because of serious confusion with a supposedly approved procedure; controllers and users were placed in unsafe situations. The arrival rate should have been lowered to a number that would accommodate one runway! That did not happen. Solution: somehow; something was changed as far as 4's a pair. I'm not sure what it was; but I suggest that all of the arrival configns be studied for accuracy and then fixed. There is no way there should be any confusion with approved procedures. Thankfully there were veteran controllers on duty and as a result; things were kept under control. I shudder to think about what could have happened if there had been less confident controllers assigned.

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Original NASA ASRS Text

Title: C90 CTLR EXPRESSED CONCERN REGARDING RWY CONFIGURATION PROC THAT RESULTED IN MULTIPLE GAR EVENTS; SUGGESTING NEW PROCS BE STUDIED.

Narrative: ORD WIND WAS 020 DEGS AT 27 KTS GUSTING TO 35 KTS; THE ARR CONFIGN WAS RWYS 10/9R AND 4R. NUMEROUS ACFT WERE EXECUTING MISSED APCHS DUE TO XWINDS IN EXCESS OF 29 KTS. THE RWY CONFIGN WAS THEN CHANGED TO RWY 4R AND RWY 4L. PROB #1: THE DUMP ZONES LISTED ON THE SYS; INDICATED THAT C90 WOULD UTILIZE AN E/W SPLIT; RWY 4R AS THE LOW SIDE AND RWY 4L THE HIGH SIDE. PROB #2: THE RWY 4R APCH PLATES HAVE A 5000 FT XING FIX (HARRL) AND THE RWY 4L APCH PLATES ONLY HAVE A 3600 FT XING FIX (KIRBY). THIS WOULD INDICATE A C90 N/S SPLIT AND RWY 4R AS THE HIGH SIDE AND RWY 4L THE LOW SIDE. PROB #3: BECAUSE OF SERIOUS CONFUSION WITH A SUPPOSEDLY APPROVED PROC; CTLRS AND USERS WERE PLACED IN UNSAFE SITUATIONS. THE ARR RATE SHOULD HAVE BEEN LOWERED TO A NUMBER THAT WOULD ACCOMMODATE ONE RWY! THAT DID NOT HAPPEN. SOLUTION: SOMEHOW; SOMETHING WAS CHANGED AS FAR AS 4'S A PAIR. I'M NOT SURE WHAT IT WAS; BUT I SUGGEST THAT ALL OF THE ARR CONFIGNS BE STUDIED FOR ACCURACY AND THEN FIXED. THERE IS NO WAY THERE SHOULD BE ANY CONFUSION WITH APPROVED PROCS. THANKFULLY THERE WERE VETERAN CTLRS ON DUTY AND AS A RESULT; THINGS WERE KEPT UNDER CTL. I SHUDDER TO THINK ABOUT WHAT COULD HAVE HAPPENED IF THERE HAD BEEN LESS CONFIDENT CTLRS ASSIGNED.

Data retrieved from NASA's ASRS site as of May 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.