Narrative:

I was working lfd sector with inbound to dtw, 1-2 overflts and a flight of 4 F16's nwbound without a d-side yet assigned. I had to vector the F16's west for the climb, vector a dtw arrival east around them and had another dtw inbound from south. I also had a dtw arrival overtop of the F16's. I had a departure to mdw climbing to 16000 ft when I got a report from ZAU that an aircraft, just leaving my airspace talking to them, had received moderate icing at 16000 ft in my airspace. I informed the air carrier and he asked for a climb. After that, I had to recoordinate the pointout and climb with 2 different sectors in ZAU since a handoff was already initiated. I also had to coordinate with dtw approach a descent for the dtw arrival because he had to stay at altitude due to the F16's. The F16 flight, all 4 aircraft, had their xponders on which caused the track to go into a coast mode and I was unable to verify the position of the lead and tail aircraft. I instructed the lead to squawk accordingly. I coordinated with the sector to the south to have the dtw inbound stopped at FL180 for traffic (F16's). I turned the dtw inbound from the southwest to a 70 degree heading for the F16, then descended him to FL190. Then I noticed that the 2 dtw inbounds were traffic since the south arrival was not yet at FL180. I instructed him to expedite the descent, stopped the other arrival at FL200, then issued turns to both aircraft. The conflict alert activated and my actions were not sufficient for separation. A d-side would have been able to reduce my workload with the extra coordination and enable me to scan the entire sector better. I would have been able to recognize the situation earlier and prevent it.

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Original NASA ASRS Text

Title: ZOB CTLR EXPERIENCED OPERROR AT FL200 WITH CRUISE AND DSCNT ACFT.

Narrative: I WAS WORKING LFD SECTOR WITH INBOUND TO DTW, 1-2 OVERFLTS AND A FLT OF 4 F16'S NWBOUND WITHOUT A D-SIDE YET ASSIGNED. I HAD TO VECTOR THE F16'S W FOR THE CLB, VECTOR A DTW ARR E AROUND THEM AND HAD ANOTHER DTW INBOUND FROM S. I ALSO HAD A DTW ARR OVERTOP OF THE F16'S. I HAD A DEP TO MDW CLBING TO 16000 FT WHEN I GOT A RPT FROM ZAU THAT AN ACFT, JUST LEAVING MY AIRSPACE TALKING TO THEM, HAD RECEIVED MODERATE ICING AT 16000 FT IN MY AIRSPACE. I INFORMED THE ACR AND HE ASKED FOR A CLB. AFTER THAT, I HAD TO RECOORDINATE THE POINTOUT AND CLB WITH 2 DIFFERENT SECTORS IN ZAU SINCE A HDOF WAS ALREADY INITIATED. I ALSO HAD TO COORDINATE WITH DTW APCH A DSCNT FOR THE DTW ARR BECAUSE HE HAD TO STAY AT ALT DUE TO THE F16'S. THE F16 FLT, ALL 4 ACFT, HAD THEIR XPONDERS ON WHICH CAUSED THE TRACK TO GO INTO A COAST MODE AND I WAS UNABLE TO VERIFY THE POS OF THE LEAD AND TAIL ACFT. I INSTRUCTED THE LEAD TO SQUAWK ACCORDINGLY. I COORDINATED WITH THE SECTOR TO THE S TO HAVE THE DTW INBOUND STOPPED AT FL180 FOR TFC (F16'S). I TURNED THE DTW INBOUND FROM THE SW TO A 70 DEG HDG FOR THE F16, THEN DSNDED HIM TO FL190. THEN I NOTICED THAT THE 2 DTW INBOUNDS WERE TFC SINCE THE S ARR WAS NOT YET AT FL180. I INSTRUCTED HIM TO EXPEDITE THE DSCNT, STOPPED THE OTHER ARR AT FL200, THEN ISSUED TURNS TO BOTH ACFT. THE CONFLICT ALERT ACTIVATED AND MY ACTIONS WERE NOT SUFFICIENT FOR SEPARATION. A D-SIDE WOULD HAVE BEEN ABLE TO REDUCE MY WORKLOAD WITH THE EXTRA COORD AND ENABLE ME TO SCAN THE ENTIRE SECTOR BETTER. I WOULD HAVE BEEN ABLE TO RECOGNIZE THE SIT EARLIER AND PREVENT IT.

Data retrieved from NASA's ASRS site as of July 2007 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.