ZDC ARTCC CTLR ASSIGNED DATA DUTIES AT A SECTOR RAPIDLY INCREASING WITH TFC. HE MOVED TO THE COORDINATOR HDOF POS AND BY THE TIME A THIRD CTLR MOVED TO THE DATA POS; A LOSS OF SEPARATION OCCURRED BTWN A DSNDING ACFT AND AN ACFT AT CRUISE ALT.

Narrative

I WAS ASKED TO SIT DOWN ON THE D-SIDE AT A SECTOR WHICH WAS BEING STAFFED BY A SINGLE CTLR. THE SECTOR WAS ALREADY QUITE BUSY WITH TFC BEING VECTORED AND DSNDED INTO CLT AND A LARGE NUMBER OF ACFT WHICH HAD BEEN RE-RTED INTO THE SECTOR WHICH WOULD NOT NORMALLY HAVE BEEN THERE. SHORTLY AFTER SITTING DOWN; I MOVED TO THE L-SIDE. EVENTUALLY WE WERE JOINED BY ANOTHER CTLR WHO TOOK THE D-SIDE. THE RADAR CTLR INITIATED A DSCNT FROM FL330 TO FL290 ON AN ACFT (#2) WHICH NEEDED TO EXIT OUR SECTOR AT FL250. FL290 HAD BEEN ISSUED BECAUSE THERE WAS TFC AT FL280. I ENTERED FL250 TEMPORARILY INTO THE DATA BLOCK AND INITIATED THE HDOF TO THE NEXT SECTOR. CONFLICT ALERT ACTIVATED AND SINCE I BELIEVED IT WAS BTWN THE DSNDING ACFT AND THE ONE AT FL280; I SUPPRESSED CAPT TO AVOID THE DISTRACTING FLASHING. A FEW MINS LATER THE D-SIDE POINTED OUT THE SIT BTWN THE DSNDING ACFT AND ONE (#1) WHICH WAS LEVEL AT FL310. THE RADAR CTLR ISSUED INSTRUCTIONS TO BOTH ACFT BUT SEPARATION WAS LOST. THE 2 FACTORS I FEEL WERE MOST IMPORTANT IN THIS SIT ARE: 1) SECTOR IMPROPERLY STAFFED (TIMELY) DUE TO LCL HABIT AND LIMITED MANPOWER. 2) TFC VOLUME AND COMPLEXITY TOO HIGH.