Narrative:

We were being vectored for traffic when a different voice came on the frequency and instructed us to climb immediately to FL230. Also, the controller reported traffic on our left side. Started the climb and the first officer reported a passenger jet passing our right side. He estimated it was within 500' vertical and 1000' horizontal. I believe that controller training was probably in progress and the student lost the picture. The airspace over washington was unusually heavy.

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Original NASA ASRS Text

Title: WHILE FOLLOWING VECTORS AND AT ASSIGNED ALT, REPORTER HAD NMAC WITH ANOTHER ACR JET.

Narrative: WE WERE BEING VECTORED FOR TFC WHEN A DIFFERENT VOICE CAME ON THE FREQ AND INSTRUCTED US TO CLB IMMEDIATELY TO FL230. ALSO, THE CTLR RPTED TFC ON OUR LEFT SIDE. STARTED THE CLB AND THE F/O RPTED A PAX JET PASSING OUR RIGHT SIDE. HE ESTIMATED IT WAS WITHIN 500' VERT AND 1000' HORIZ. I BELIEVE THAT CTLR TRNING WAS PROBABLY IN PROGRESS AND THE STUDENT LOST THE PICTURE. THE AIRSPACE OVER WASHINGTON WAS UNUSUALLY HEAVY.

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.