Narrative:

LJ35 was on an overflt of my sector at 9000 ft MSL northwest to southeast. P180 was handed off by the center at 10000 ft MSL on the COATT4 arrival; southwest to northeast. I determined that although the aircraft were on converging courses a descent was possible because the diverging course rule would apply as soon as the LJ35 crossed the path of the P180. Thus I instructed ZDC to descend the P180 to 6000 ft MSL and switch him to me. The P180 checked in and I acknowledged with the richmond altimeter. No traffic was issued at this time. I was very busy at the time and falling behind in my work. Illness was a factor. I dealt with several other issues and returned my attention to the P180 to affect a handoff to the next sector. At that time I saw that although the divergence rule had worked the aircraft were in very close proximity. I instructed the LJ35 to turn left immediately for traffic. His response was we have the traffic and are maintaining visual separation. No evasive maneuvers were taken by either aircraft. I asked if either aircraft had a problem and they both replied negative. I advised that it was closer than I like but no harm no foul. I then informed my supervisor that I needed to be relieved from position as I was not able to keep up with the workload and was making mistakes. He had me relieved and I advised him of the situation with the LJ35 and the P180. I fully described the traffic situation and the rules that I had applied. My last statement to him was; the 15 degree divergence rule and no merging target rule may be legal; but I was going to refrain from using it in the future because it can allow aircraft to get scary close. The supervisor agreed with that assessment. No further action taken at this time.

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Original NASA ASRS Text

Title: PCT CTLR DESCRIBED CONFLICT EVENT WHEN UTILIZING DIVERGING SEPARATION RULE; LAST MINUTE CTLR INTERVENTION WAS REQUIRED TO SAVE SEPARATION.

Narrative: LJ35 WAS ON AN OVERFLT OF MY SECTOR AT 9000 FT MSL NW TO SE. P180 WAS HANDED OFF BY THE CTR AT 10000 FT MSL ON THE COATT4 ARR; SW TO NE. I DETERMINED THAT ALTHOUGH THE ACFT WERE ON CONVERGING COURSES A DSCNT WAS POSSIBLE BECAUSE THE DIVERGING COURSE RULE WOULD APPLY AS SOON AS THE LJ35 CROSSED THE PATH OF THE P180. THUS I INSTRUCTED ZDC TO DSND THE P180 TO 6000 FT MSL AND SWITCH HIM TO ME. THE P180 CHKED IN AND I ACKNOWLEDGED WITH THE RICHMOND ALTIMETER. NO TFC WAS ISSUED AT THIS TIME. I WAS VERY BUSY AT THE TIME AND FALLING BEHIND IN MY WORK. ILLNESS WAS A FACTOR. I DEALT WITH SEVERAL OTHER ISSUES AND RETURNED MY ATTN TO THE P180 TO AFFECT A HDOF TO THE NEXT SECTOR. AT THAT TIME I SAW THAT ALTHOUGH THE DIVERGENCE RULE HAD WORKED THE ACFT WERE IN VERY CLOSE PROX. I INSTRUCTED THE LJ35 TO TURN L IMMEDIATELY FOR TFC. HIS RESPONSE WAS WE HAVE THE TFC AND ARE MAINTAINING VISUAL SEPARATION. NO EVASIVE MANEUVERS WERE TAKEN BY EITHER ACFT. I ASKED IF EITHER ACFT HAD A PROB AND THEY BOTH REPLIED NEGATIVE. I ADVISED THAT IT WAS CLOSER THAN I LIKE BUT NO HARM NO FOUL. I THEN INFORMED MY SUPVR THAT I NEEDED TO BE RELIEVED FROM POS AS I WAS NOT ABLE TO KEEP UP WITH THE WORKLOAD AND WAS MAKING MISTAKES. HE HAD ME RELIEVED AND I ADVISED HIM OF THE SITUATION WITH THE LJ35 AND THE P180. I FULLY DESCRIBED THE TFC SITUATION AND THE RULES THAT I HAD APPLIED. MY LAST STATEMENT TO HIM WAS; THE 15 DEG DIVERGENCE RULE AND NO MERGING TARGET RULE MAY BE LEGAL; BUT I WAS GOING TO REFRAIN FROM USING IT IN THE FUTURE BECAUSE IT CAN ALLOW ACFT TO GET SCARY CLOSE. THE SUPVR AGREED WITH THAT ASSESSMENT. NO FURTHER ACTION TAKEN AT THIS TIME.

Data retrieved from NASA's ASRS site as of May 2009 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.