Narrative:

Air carrier X had just departed rdu and was wbound, just leveling at 10000' when he came over. I called traffic (another IFR) and issued climb clearance. He then asked about the traffic and I told him the IFR traffic's position south of him. He said traffic was very close. I then observed a VFR target going behind air carrier X. After a few updates, the altitude encoder showed up, 9800'. The VFR evidently saw air carrier X and had just turned his transponder on. The air carrier pilot said he would file a near midair report. I advised the supervisor in charge.

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Original NASA ASRS Text

Title: ACR X REPORTER PASSING CLOSE PROX TO AN UNIDENTIFIED VFR ACFT.

Narrative: ACR X HAD JUST DEPARTED RDU AND WAS WBOUND, JUST LEVELING AT 10000' WHEN HE CAME OVER. I CALLED TFC (ANOTHER IFR) AND ISSUED CLB CLRNC. HE THEN ASKED ABOUT THE TFC AND I TOLD HIM THE IFR TFC'S POS S OF HIM. HE SAID TFC WAS VERY CLOSE. I THEN OBSERVED A VFR TARGET GOING BEHIND ACR X. AFTER A FEW UPDATES, THE ALT ENCODER SHOWED UP, 9800'. THE VFR EVIDENTLY SAW ACR X AND HAD JUST TURNED HIS XPONDER ON. THE ACR PLT SAID HE WOULD FILE A NEAR MIDAIR RPT. I ADVISED THE SUPVR IN CHARGE.

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.