ZOB DEVELOPMENTAL EXPERIENCED OPERROR AT FL350 WHILE FOCUSED ON ANOTHER PROBLEM AND FAILING TO RECOGNIZE A DEVELOPING CONFLICT.

Narrative

ACFT Y FLT TO CLT NEEDED TO BE IN TRAIL WITH 3 OTHER ACFT GOING TO CLT. ACFT Y WAS PUT ON A 275 DEG HDG FOR SPACING. ACFT X WAS A DEP OUT OF CVG GOING OVER PSB AT FL350. ANOTHER SITUATION PRESENTED ITSELF AND ACFT Z HAD TO BE CLBED TO FL350 SBOUND. THIS PUT ACFT Y IN CONFLICT WITH ACFT Z. ACFT Y WAS PUT ON A 200 DEG HDG TO AVOID ACFT Z. THIS PUT THE ACFT Y IN CONFLICT WITH ACFT X. ACFT X ATTEMPTED TO CHK ON FREQ TWICE; DURING A TIME WHEN MORE CRITICAL CLRNC NEEDED TO BE GIVEN. ON THE THIRD CHK-IN FROM ACFT X; HE ASKED WHO THE TFC WAS OFF HIS L SIDE. HDGS WERE ISSUED IMMEDIATELY; BOTH ACFT RESPONDED TO RA'S. ACFT Y DSNDED AND ACFT X CLBED. BOTH ACFT WERE RETURNED ON COURSE. SUPPLEMENTAL INFO FROM ACN 778056: ACFT Y WAS BEING VECTORED TO ACCOMPLISH IN TRAIL SPACING REQUIREMENTS. AT THE TIME OF THE INCIDENT; ANOTHER TFC SITUATION WAS ALSO GOING ON REQUIRING MULTIPLE CLRNCS AND COORDS WITH OTHER SECTORS. THEN ACFT X CALLED AGAIN; BUT THIS TIME ASKED ABOUT TFC OFF HIS L; WHICH IS WHAT CALLED OUR ATTN TO THE SITUATION BTWN ACFT Y AND ACFT X.