Narrative:

I was working several aircraft inbound to ord; including one routed from the north over the shiky arrival (a CRJ7) that needed to be sequenced with the aircraft inbound from the west. There was a fair amount of other traffic in the airspace at the time; several aircraft on frequency need to descend through the arrival traffic to destination airports in the vicinity. Also at the same time; parachute jumping was going on over the beloit airport; [the jump plane] was circling up to 14;500 ft directly underneath the ord arrival stream. A pc-12; an ryv arrival from the south; requested lower; I issued 14;000; attempting to keep that aircraft underneath the ord arrivals. I thought the pc-12 would be laterally separated from the CRJ7; however; I must have misjudged the distance and standard separation was lost. The CRJ7 reported responding to an RA. I do not know if the RA was with [the jump plane] or the pc-12. I believe the parachute jump operation at the beloit; wi airport is a safety risk at farmm sector. The jump aircraft are constantly in conflict with IFR traffic; particularly ord arrivals; as the bullz and jvl stars route arrivals right through the airspace the jump aircraft circle. Constantly issuing traffic advisories about the jump aircraft to IFR traffic during a rush distracts from other tasks at hand and adds significantly to what can be an already heavy workload. During the time period in question; I spent a fair amount of time/effort on the jump aircraft; attempting to plan for their climb; issuing traffic; etc. Without such a large distraction in play; it would've been significantly easier to realize and correct the error I made in regards to misjudging how much separation I had between the CRJ7 and the pc-12.

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Original NASA ASRS Text

Title: ZAU Controller experienced a loss of separation event listing parachute activity in the vicinity as work intensive and distracting from duties required of ORD arrivals.

Narrative: I was working several aircraft inbound to ORD; including one routed from the north over the SHIKY arrival (a CRJ7) that needed to be sequenced with the aircraft inbound from the west. There was a fair amount of other traffic in the airspace at the time; several aircraft on frequency need to descend through the arrival traffic to destination airports in the vicinity. Also at the same time; parachute jumping was going on over the Beloit airport; [the jump plane] was circling up to 14;500 FT directly underneath the ORD arrival stream. A PC-12; an RYV arrival from the south; requested lower; I issued 14;000; attempting to keep that aircraft underneath the ORD arrivals. I thought The PC-12 would be laterally separated from the CRJ7; however; I must have misjudged the distance and standard separation was lost. The CRJ7 reported responding to an RA. I do not know if the RA was with [the jump plane] or the PC-12. I believe the parachute jump operation at the Beloit; WI airport is a safety risk at FARMM Sector. The jump aircraft are constantly in conflict with IFR traffic; particularly ORD arrivals; as the BULLZ and JVL STARs route arrivals right through the airspace the jump aircraft circle. Constantly issuing traffic advisories about the jump aircraft to IFR traffic during a rush distracts from other tasks at hand and adds significantly to what can be an already heavy workload. During the time period in question; I spent a fair amount of time/effort on the jump aircraft; attempting to plan for their climb; issuing traffic; etc. Without such a large distraction in play; it would've been significantly easier to realize and correct the error I made in regards to misjudging how much separation I had between the CRJ7 and the PC-12.

Data retrieved from NASA's ASRS site as of July 2013 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.