ACR Y DSCNT THROUGH OCCUPIED ALT HAD LTSS FROM ACR X. SYS ERROR.

Narrative

ACR X WAS SBOUND J53 AT FL310 ALREADY HANDED OFF TO NEXT SECTOR. ACR Y COMING FROM SAME SECTOR WAS NBOUND AT FL330. (ACR SHOULD HAVE BEEN DSNDING TO FL290 FROM PREVIOUS SECTOR.) THAT SECTOR COORDINATED WITH ME THAT ACR Y WAS MY CTL REF OTHER ACFT. I HAD TRIED TO REPOS ACR X DATA BLOCK BUT MISSED THE FIRST NUMBER IN THE COMPUTER ENTRY. THE DATA BLOCK THEN DROPPED OFF MY SCOPE. I WAS BUSY SPACING PITTSBURGH ARRS AND DIDN'T REALIZE ACR X DATA BLOCK WAS GONE. AS SOON AS ACR Y CHKED ON FREQ I DSNDED HIM TO FL250 OVER TOP OF ACR X. HE DSNDED SLOWLY AND THE DATA BLOCKS WENT INTO CONFLICT ALERT. (THEY WERE OVERLAPPING AT THE TIME.) BY THE TIME I REPOSITIONED THE DATA BLOCKS TO SEE WHAT WAS HAPPENING; ACR Y WAS ALREADY IN DSCNT JUST N OF ACR X. I ASKED ACR Y ALT. HE SAID FL326. I THEN CLBED ACR Y BACK TO FL330. THE MAIN CONTRIBUTING FACTOR WAS NOT HAVING ACR X DATA BLOCK ON MY SCOPE. I DIDN'T REALIZE WHERE ACR X WAS WHEN I DSNDED THE JET BECAUSE OF THE MISSING DATA BLOCK. SECONDARY FACTOR WAS THE SECTOR HANDING OFF ACR Y TO ME DID NOT HAVE ACR DSNDING TO FL290 FORCING ME TO DEAL WITH THE SIT.