Narrative:

Air carrier X eastbound of ord over crl VOR climbing slowly to FL370 was assigned heading 070 degrees to facilitate 2 nwbound medium large transport's at FL350, one of which was assigned a heading of 285 degrees behind him at FL350, the other on a northeast heading for climb to FL350 for medium large transport southeast at FL330. When the nebound traffic leveled at FL350 he was turned to a 270 degree heading to go behind air carrier X, a cpr Y who was also eastbound was assigned a 070 degree heading to parallel air carrier X. The aircraft that was on the 270 degree heading and the air carrier X still did not have the required 5 mi lateral separation with each other so air carrier X was turned to a 360 degree heading and the medium large transport to a 250 degree heading to keep 5 mi lateral separation. This 250 degree heading made him traffic with the other aircraft who had been turned to a 360 degree heading to follow the first medium large transport at FL350 for spacing to msp. There at this time were several other aircraft on frequency who were on headings for the spacing to msp. As I was alleviating the situation with the 2 medium large transport aircraft at FL350, air carrier X had become traffic with the cpr Y with a rapid rate of closure. I tried to turn cpr Y to a 360 degree heading and air carrier X to 180 degrees but separation had become lost.

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Original NASA ASRS Text

Title: ACR X CLB TO OCCUPIED ALT HAD LTSS FROM CPR Y. SYS ERROR.

Narrative: ACR X EBOUND OF ORD OVER CRL VOR CLBING SLOWLY TO FL370 WAS ASSIGNED HDG 070 DEGS TO FACILITATE 2 NWBOUND MLG'S AT FL350, ONE OF WHICH WAS ASSIGNED A HDG OF 285 DEGS BEHIND HIM AT FL350, THE OTHER ON A NE HDG FOR CLB TO FL350 FOR MLG SE AT FL330. WHEN THE NEBOUND TFC LEVELED AT FL350 HE WAS TURNED TO A 270 DEG HDG TO GO BEHIND ACR X, A CPR Y WHO WAS ALSO EBOUND WAS ASSIGNED A 070 DEG HDG TO PARALLEL ACR X. THE ACFT THAT WAS ON THE 270 DEG HDG AND THE ACR X STILL DID NOT HAVE THE REQUIRED 5 MI LATERAL SEPARATION WITH EACH OTHER SO ACR X WAS TURNED TO A 360 DEG HDG AND THE MLG TO A 250 DEG HDG TO KEEP 5 MI LATERAL SEPARATION. THIS 250 DEG HDG MADE HIM TFC WITH THE OTHER ACFT WHO HAD BEEN TURNED TO A 360 DEG HDG TO FOLLOW THE FIRST MLG AT FL350 FOR SPACING TO MSP. THERE AT THIS TIME WERE SEVERAL OTHER ACFT ON FREQ WHO WERE ON HDGS FOR THE SPACING TO MSP. AS I WAS ALLEVIATING THE SIT WITH THE 2 MLG ACFT AT FL350, ACR X HAD BECOME TFC WITH THE CPR Y WITH A RAPID RATE OF CLOSURE. I TRIED TO TURN CPR Y TO A 360 DEG HDG AND ACR X TO 180 DEGS BUT SEPARATION HAD BECOME LOST.

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.