Narrative:

Aircraft X was northbound on routing mrb V501 at 8000 ft. ZDC had already accepted a handoff prior to mrb VOR. ZDC called for a manual handoff on aircraft Y. Aircraft Y was sbound, opposite direction, mrb then V143. ZDC was flashing the aircraft at the wrong sector. I had only a limited data tag on aircraft Y. The aircraft Y was already crossing my boundary line, entering my airspace without a handoff. I took radar on aircraft Y without realizing he was at 8000 ft. I made ARTS entries to assign the aircraft to my tag. I then saw the altitude was 8000 ft. I then turned aircraft X wbound and descended him to 7000 ft to avoid the traffic. I was only talking to aircraft X at the time of incident. Aircraft X was slow turning and descending. Traffic was called to aircraft X and he replied we have him on TCASII. Aircraft Y checked in and advised me he was getting a TA. He was about 1 1/2 mi east of aircraft X at the same altitude. If ZDC had flashed aircraft Y, on the correct scope, this situation, more than likely would have been avoided. Had ZDC completed a handoff prior to entering my airspace, this situation could have been avoided. ZDC had already accepted the handoff on the traffic I was giving to them. They should have resolved the confliction prior to making a handoff with me. Also the aircraft data tag was blocked by another data tag when I first observed it. ZDC did coordinate 8000 ft on the landline at the time of the manual handoff. I did not catch the altitude at the time due to the close proximity to my airspace. I was trying to help out another controller from having an airspace deviation, not realizing he would be handing off an aircraft at the same altitude I was giving him.

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Original NASA ASRS Text

Title: LOSS OF SEPARATION OCCURRED BTWN A TBM700 NBOUND HANDED OFF TO ZDC BY PCT TRACON AND A BE53 SBOUND HANDED OFF TO PCT BY ZDC. BOTH ACFT WERE AT 8000 FT.

Narrative: ACFT X WAS NBOUND ON ROUTING MRB V501 AT 8000 FT. ZDC HAD ALREADY ACCEPTED A HDOF PRIOR TO MRB VOR. ZDC CALLED FOR A MANUAL HDOF ON ACFT Y. ACFT Y WAS SBOUND, OPPOSITE DIRECTION, MRB THEN V143. ZDC WAS FLASHING THE ACFT AT THE WRONG SECTOR. I HAD ONLY A LIMITED DATA TAG ON ACFT Y. THE ACFT Y WAS ALREADY XING MY BOUNDARY LINE, ENTERING MY AIRSPACE WITHOUT A HDOF. I TOOK RADAR ON ACFT Y WITHOUT REALIZING HE WAS AT 8000 FT. I MADE ARTS ENTRIES TO ASSIGN THE ACFT TO MY TAG. I THEN SAW THE ALT WAS 8000 FT. I THEN TURNED ACFT X WBOUND AND DSNDED HIM TO 7000 FT TO AVOID THE TFC. I WAS ONLY TALKING TO ACFT X AT THE TIME OF INCIDENT. ACFT X WAS SLOW TURNING AND DSNDING. TFC WAS CALLED TO ACFT X AND HE REPLIED WE HAVE HIM ON TCASII. ACFT Y CHKED IN AND ADVISED ME HE WAS GETTING A TA. HE WAS ABOUT 1 1/2 MI E OF ACFT X AT THE SAME ALT. IF ZDC HAD FLASHED ACFT Y, ON THE CORRECT SCOPE, THIS SIT, MORE THAN LIKELY WOULD HAVE BEEN AVOIDED. HAD ZDC COMPLETED A HDOF PRIOR TO ENTERING MY AIRSPACE, THIS SIT COULD HAVE BEEN AVOIDED. ZDC HAD ALREADY ACCEPTED THE HDOF ON THE TFC I WAS GIVING TO THEM. THEY SHOULD HAVE RESOLVED THE CONFLICTION PRIOR TO MAKING A HDOF WITH ME. ALSO THE ACFT DATA TAG WAS BLOCKED BY ANOTHER DATA TAG WHEN I FIRST OBSERVED IT. ZDC DID COORDINATE 8000 FT ON THE LANDLINE AT THE TIME OF THE MANUAL HDOF. I DID NOT CATCH THE ALT AT THE TIME DUE TO THE CLOSE PROX TO MY AIRSPACE. I WAS TRYING TO HELP OUT ANOTHER CTLR FROM HAVING AN AIRSPACE DEV, NOT REALIZING HE WOULD BE HANDING OFF AN ACFT AT THE SAME ALT I WAS GIVING HIM.

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.