Narrative:

The event was an near midair collision with a commercial airliner. The entire incident took place over about 30-40 seconds. While on a southwest/west vector from atl departure control and cleared for a climb from 4000 ft to 5000 ft MSL, I recognized another aircraft at my 2-3 O'clock position and about 4 mi away (no TA was given and the departure frequency was congested). After determining their direction of flight and altitude (they were also climbing), it became obvious that we were on a collision course. I deviated from my assigned heading with a descending turn to the left. The other aircraft responded with a climbing left turn. I estimate that we were within 100-300 ft of a collision. After the deviation, I notified atl departure control of a 'near miss' and verified that I was cleared for climb to 5000 ft. The controller verified my climb and indicated that they were 'looking into the incident.' prior to being handed off to the next departure controller, I restated my concern about the incident to the controller. I stated that a collision was avoided by approximately 1-2 seconds. The controller responded by stating, 'we are investigating and we weren't sure why he was down that low.' I assumed that he meant the other aircraft. No other information was given to me. I am unsure as to the type of aircraft or the airline to which the other aircraft was affiliated. Additionally, they were not assigned the same radio frequency that I was using so I couldn't hear their responses. I descended from 4800 ft to 4000 ft and turned left by approximately 40 degrees. I estimate the other aircraft climbed 500- 1000 ft above his/her altitude and turned left by 30-80 degrees. Supplemental information from acn 379607: air carrier Y L1011 and atx X BE58 near midair collision, approximately 10 mi southwest atl at 5000 ft. The following factors were involved: lack of staffing during abnormal WX conditions, multiple coordination, WX conditions that were causing aircraft to deviation from normal departure arrival rtes, traffic density, unusual requests, frequency congestion, xover traffic, misapplication of departure procedures by the tower. I turned the L1011 to a heading of 150 degrees for course divergence and to continue climbing the L1011. The L1011 and the BE58 were at the same altitude. TCASII activated and directed the L1011 to descend. The BE58 saw the L1011 at his altitude and he descended as well. Both aircraft were descending 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.

Google
 

Original NASA ASRS Text

Title: 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.

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.