ARTCC RADAR CTLR ISSUED UNKNOWN VFR TFC TO ACR LTT AS SOON AS THE CTLR OBSERVED IT. ACR FLC DID NOT SEE TFC IMMEDIATELY; BUT AFTER SECOND TA THE SMA WAS SEEN AND THE ACR LTT DSNDED TO EVADE THE VFR SMA. NMAC RPTS ARE BEING FILED BY THE ACR FLC AND THE ARTCC RADAR CTLR.

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AT XA54 I WAS ISSUING A CLRNC FROM DANVILLE REGIONAL ARPT. I HUNG UP DURING THE READBACK TO ISSUE A VFR TFC CALL TO ACR X ON SMA Y 12 O'CLOCK 2 MI 9400 FT. I OBSERVED THE NEXT SWEEP OF THE TARGET AT 9200 FT. I; IMMEDIATELY ISSUED ANOTHER TFC CALL. THE PLT STATED 'ROGER; WE ARE GOING DOWN.' I OBSERVED THE VFR TARGET WHILE IT APPEARED TO TURN AROUND AND TO GO BACK THE OTHER WAY. THE PLT SAID HE HAD THE ACFT IN SIGHT; AND THEY MISSED BY 200 FT. HE SAID HE WAS CLBING BACK UP TO 9000 FT. I ASKED HIM IF HE SAW THE TFC BEFORE I CALLED IT. HE STATED 'NO.' HE SAID IT WAS DEFINITELY A NEAR MISS AND THAT PAPERWORK SHOULD BE STARTED ON IT. SUPPLEMENTAL INFO FROM ACN 319583: ATC CALLED OUT TFC 12 O'CLOCK 2 MI 9400 FT DSNDING. AFTER SEARCHING 10-15 SECONDS THE ACFT WAS ACQUIRED; 12 O'CLOCK AND 1 MI. AT SAME TIME ATC ISSUED A L TURN TO AVOID THE ACFT. IT WAS TOO LATE TO START A TURN SO A DSCNT WAS STARTED TO AVOID THE ACFT. UPON DSNDING TO 8500 FT THE ACFT PASSED 200 FT ABOVE US STILL DSNDING. SUPPLEMENTAL INFO FROM ACN 319584: I WAS FLYING A BEECH 1900C IN CRUISE AT 9000 FT. WE WERE BEING CTLED BY ZDC ON AN IFR FLT PLAN ENRTE FROM GREENSBORO; NC; TO RICHMOND; VA. THE ACFT WAS BEING OPERATED AT 220 KIAS. THE CTR CTLR CALLED TFC AT '12 O'CLOCK AND 2 MI AT 9400 FT.' THE FO AND MYSELF SEARCHED FOR THE TFC AND THE LNDG LIGHTS WERE ACTIVATED. WITHIN 30 SECONDS; THE CTLR STATED 'TFC 12 O'CLOCK; 1 MI; TURN L TO 320 DEGS IF NOT IN SIGHT.' AT THAT TIME WE SAW THE TFC. IT APPEARED TO BE DSNDING HEAD- ON AND WAS FIXED IN THE WINDSHIELD. DUE TO THE CLOSURE RATE AND PROX OF THE OTHER ACFT; I ELECTED TO DSND AWAY FROM THE TFC. WE DSNDED TO 8500 FT AS THE TFC PASSED OVERHEAD BY APPROX 200 FT. UPON PASSING; WE CLBED BACK TO OUR PREVIOUS ASSIGNED ALT OF 9000 FT. THE ACFT APPEARED TO BE A LOW WING; 4 SEAT VERSION WITH FIXED GEAR; POSSIBLY A GRUMMAN. NO INJURIES WERE SUSTAINED; NOR ANY PAX DISCOMFORT WAS NOTED. NMAC PROCS WERE STARTED WITH CTR AND FSDO. UNKNOWN HOW LONG ACFT WAS ON CTLR'S SCREEN PRIOR TO CALLING TFC TO CREW. CREW ONLY GIVEN A 2 MI WARNING. CLOSURE RATE IS ESTIMATED AT 5 MI PER MIN. OTHER ACFT BEING OPERATED WITHOUT COMMUNICATING WITH CTR. OUR ACFT RESTR TO LOWER LEVELS DUE TO MEL'ED PRESSURIZATION. PROHIBIT UNCTLED VFR FLT ABOVE 1000 FT AGL. DO NOT DELAY SAFETY PROGRAMS; IE; MANDATORY XPONDERS; AND TCASII INSTALLATION.