A RADAR CTLR BUSY VECTORING ACFT DUE TO WX ALLOWS AN ATX BE58 AND AN OPPOSITE DIRECTION L1011 TO PASS AT THE SAME ALT APPROX ONE HALF MI APART.

Narrative

THE EVENT WAS AN NMAC WITH A COMMERCIAL AIRLINER. THE ENTIRE INCIDENT TOOK PLACE OVER ABOUT 30-40 SECONDS. WHILE ON A SW/W VECTOR FROM ATL DEP CTL AND CLRED FOR A CLB FROM 4000 FT TO 5000 FT MSL; I RECOGNIZED ANOTHER ACFT AT MY 2-3 O'CLOCK POS AND ABOUT 4 MI AWAY (NO TA WAS GIVEN AND THE DEP FREQ WAS CONGESTED). AFTER DETERMINING THEIR DIRECTION OF FLT AND ALT (THEY WERE ALSO CLBING); IT BECAME OBVIOUS THAT WE WERE ON A COLLISION COURSE. I DEVIATED FROM MY ASSIGNED HDG WITH A DSNDING TURN TO THE L. THE OTHER ACFT RESPONDED WITH A CLBING L TURN. I ESTIMATE THAT WE WERE WITHIN 100-300 FT OF A COLLISION. AFTER THE DEV; I NOTIFIED ATL DEP CTL OF A 'NEAR MISS' AND VERIFIED THAT I WAS CLRED FOR CLB TO 5000 FT. THE CTLR VERIFIED MY CLB AND INDICATED THAT THEY WERE 'LOOKING INTO THE INCIDENT.' PRIOR TO BEING HANDED OFF TO THE NEXT DEP CTLR; I RESTATED MY CONCERN ABOUT THE INCIDENT TO THE CTLR. I STATED THAT A COLLISION WAS AVOIDED BY APPROX 1-2 SECONDS. THE CTLR RESPONDED BY STATING; 'WE ARE INVESTIGATING AND WE WEREN'T SURE WHY HE WAS DOWN THAT LOW.' I ASSUMED THAT HE MEANT THE OTHER ACFT. NO OTHER INFO WAS GIVEN TO ME. I AM UNSURE AS TO THE TYPE OF ACFT OR THE AIRLINE TO WHICH THE OTHER ACFT WAS AFFILIATED. ADDITIONALLY; THEY WERE NOT ASSIGNED THE SAME RADIO FREQ THAT I WAS USING SO I COULDN'T HEAR THEIR RESPONSES. I DSNDED FROM 4800 FT TO 4000 FT AND TURNED L BY APPROX 40 DEGS. I ESTIMATE THE OTHER ACFT CLBED 500- 1000 FT ABOVE HIS/HER ALT AND TURNED L BY 30-80 DEGS. SUPPLEMENTAL INFO FROM ACN 379607: ACR Y L1011 AND ATX X BE58 NMAC; APPROX 10 MI SW ATL AT 5000 FT. THE FOLLOWING FACTORS WERE INVOLVED: LACK OF STAFFING DURING ABNORMAL WX CONDITIONS; MULTIPLE COORD; WX CONDITIONS THAT WERE CAUSING ACFT TO DEV FROM NORMAL DEP ARR RTES; TFC DENSITY; UNUSUAL REQUESTS; FREQ CONGESTION; XOVER TFC; MISAPPLICATION OF DEP PROCS BY THE TWR. I TURNED THE L1011 TO A HDG OF 150 DEGS FOR COURSE DIVERGENCE AND TO CONTINUE CLBING THE L1011. THE L1011 AND THE BE58 WERE AT THE SAME ALT. TCASII ACTIVATED AND DIRECTED THE L1011 TO DSND. THE BE58 SAW THE L1011 AT HIS ALT AND HE DSNDED AS WELL. BOTH ACFT WERE DSNDING TO AVOID BUT NOTHING WAS BEING RESOLVED. CONFLICT ALERT ACTIVATED AT 1.5 MI BUT 5 DATA TAGS WERE ALL OVERLAPPING. I COULD NOT TELL WHO WAS IN CONFLICT WITH WHO AND WAS UNABLE TO REACT TO THE ALERT.