Narrative:

The flight was cleared out of 13000' MSL to 12000' MSL, along an assigned published airway, (V-378). In very clear VFR conditions both myself and the first officer observed an aircraft rotating beacon directly in front of our aircraft. As the distance quickly appeared to be growing shorter, ATC advised us of a VFR target '12 O'clock less than a mile, 12500' MSL.' we were descending through 12600' and therefore quickly turned left for avoidance. ATC was advised and the flight continued west/O any further problems. ATC informed us that he had 'forgotten' about the traffic as we were cleared through his altitude.

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Original NASA ASRS Text

Title: WHILE IN DESCENT, IFR MLG CAME IN CLOSE PROX TO OPPOSITE DIRECTION VFR TRAFFIC. NMAC.

Narrative: THE FLT WAS CLRED OUT OF 13000' MSL TO 12000' MSL, ALONG AN ASSIGNED PUBLISHED AIRWAY, (V-378). IN VERY CLR VFR CONDITIONS BOTH MYSELF AND THE F/O OBSERVED AN ACFT ROTATING BEACON DIRECTLY IN FRONT OF OUR ACFT. AS THE DISTANCE QUICKLY APPEARED TO BE GROWING SHORTER, ATC ADVISED US OF A VFR TARGET '12 O'CLOCK LESS THAN A MILE, 12500' MSL.' WE WERE DSNDING THROUGH 12600' AND THEREFORE QUICKLY TURNED LEFT FOR AVOIDANCE. ATC WAS ADVISED AND THE FLT CONTINUED W/O ANY FURTHER PROBS. ATC INFORMED US THAT HE HAD 'FORGOTTEN' ABOUT THE TFC AS WE WERE CLRED THROUGH HIS ALT.

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.