Narrative:

I took over the position (D4) with a trnee at XX38Z. At that time the northbound rush was starting and we found ourselves running out of northbound altitude (right altitude for direction of flight). I requested FL370 for widebody transport Z on A300 and was denied by the new york controller. During the rush I had traffic northbound at FL280 (large transport Y) and another behind him (large transport west), also requesting FL280 or FL310. FL310 was unable due to widebody transport T at that altitude. The only choice for large transport X was FL260, unless I could get approval from new your center for a higher altitude wrong for direction. I scanned the bay to see if their was any traffic southbound at FL290 and only observed one, large transport V, which was estimating lennt at XY11Z. Large transport Y was estimating lennt at XY15Z. I called new york center and requested FL290 for large transport Y. At that time it was approved with neither new york controller nor myself recognizing the potential conflict with widebody transport X. I informed the radar person that FL290 was approved reference large transport V observed on radar. I was informed about the near miss between widebody transport X and large transport Y at XY49Z by communication radio. At the time of the incident I was working approximately 25 aircraft. I could only recommend that a flow restriction be applied to relieve the stress. Supplemental information from acn 87769: flying northbound from sju to phl, the crew and I encountered a near midair collision with a southbound flight. We were both cleared the same route and flight level by 2 different ATC facs. The southbound aircraft passed 300' off our starboard wing. ATC was immediately notified.

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Original NASA ASRS Text

Title: ACR-WDB CLEARED SOUTHEASTBOUND ON A300 AND ACR-LGT CLEARED NORTHWESTBOUND ON A300, BOTH AT FL290, RESULTING IN NMAC AND LESS THAN STANDARD SEPARATION.

Narrative: I TOOK OVER THE POS (D4) WITH A TRNEE AT XX38Z. AT THAT TIME THE NBOUND RUSH WAS STARTING AND WE FOUND OURSELVES RUNNING OUT OF NBOUND ALT (RIGHT ALT FOR DIRECTION OF FLT). I REQUESTED FL370 FOR WDB Z ON A300 AND WAS DENIED BY THE NEW YORK CTLR. DURING THE RUSH I HAD TFC NBOUND AT FL280 (LGT Y) AND ANOTHER BEHIND HIM (LGT W), ALSO REQUESTING FL280 OR FL310. FL310 WAS UNABLE DUE TO WDB T AT THAT ALT. THE ONLY CHOICE FOR LGT X WAS FL260, UNLESS I COULD GET APPROVAL FROM NEW YOUR CENTER FOR A HIGHER ALT WRONG FOR DIRECTION. I SCANNED THE BAY TO SEE IF THEIR WAS ANY TFC SBND AT FL290 AND ONLY OBSERVED ONE, LGT V, WHICH WAS ESTIMATING LENNT AT XY11Z. LGT Y WAS ESTIMATING LENNT AT XY15Z. I CALLED NEW YORK CENTER AND REQUESTED FL290 FOR LGT Y. AT THAT TIME IT WAS APPROVED WITH NEITHER NEW YORK CTLR NOR MYSELF RECOGNIZING THE POTENTIAL CONFLICT WITH WDB X. I INFORMED THE RADAR PERSON THAT FL290 WAS APPROVED REF LGT V OBSERVED ON RADAR. I WAS INFORMED ABOUT THE NEAR MISS BTWN WDB X AND LGT Y AT XY49Z BY COM RADIO. AT THE TIME OF THE INCIDENT I WAS WORKING APPROX 25 ACFT. I COULD ONLY RECOMMEND THAT A FLOW RESTRICTION BE APPLIED TO RELIEVE THE STRESS. SUPPLEMENTAL INFO FROM ACN 87769: FLYING NBOUND FROM SJU TO PHL, THE CREW AND I ENCOUNTERED A NMAC WITH A SBND FLT. WE WERE BOTH CLRED THE SAME ROUTE AND FLT LEVEL BY 2 DIFFERENT ATC FACS. THE SBND ACFT PASSED 300' OFF OUR STARBOARD WING. ATC WAS IMMEDIATELY NOTIFIED.

Data retrieved from NASA's ASRS site as of August 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.