Narrative:

I was in cruise on an IFR flight plan over northwestern arkansas. Center called me with a traffic alert of unknown aircraft, 2 O'clock position, indicated altitude 6000 ft, as I recall. I responded that I was looking for the aircraft. After several seconds without visual contact, I called center to state that I was entering heavy clouds and asked for an update on the other aircraft's position. I got no response from center. Meanwhile, just before entering the clouds, my mode south transponder became active, showing a target aircraft at 2 O'clock position, climbing and just outside the 2 mi circle. As I entered the clouds, I got an audible 'traffic' alert, indicated position of -500 ft and less than 1 mi. I performed a climbing l-hand turn until the target cleared. My passenger later stated that the target turned red and merged with the departure of my aircraft on the GPS situation display. After recovering on course, I made 2 attempts to contact ZME that went unanswered. To other calling aircraft, the controller kept telling them to stand by as he was experiencing computer problems. Some mins late when I was given a frequency change, I asked the controller about my experience and was told that he knew nothing as they had just changed controllers.

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Original NASA ASRS Text

Title: PLT OF SR22 ON AN IFR FLT PLAN WITH ZME EXPERIENCES CRITICAL ENCOUNTER WITH UNIDENTED ACFT. WARNED BY MODE S XPONDER COLLISION AVOIDANCE SYS.

Narrative: I WAS IN CRUISE ON AN IFR FLT PLAN OVER NORTHWESTERN ARKANSAS. CTR CALLED ME WITH A TFC ALERT OF UNKNOWN ACFT, 2 O'CLOCK POS, INDICATED ALT 6000 FT, AS I RECALL. I RESPONDED THAT I WAS LOOKING FOR THE ACFT. AFTER SEVERAL SECONDS WITHOUT VISUAL CONTACT, I CALLED CTR TO STATE THAT I WAS ENTERING HVY CLOUDS AND ASKED FOR AN UPDATE ON THE OTHER ACFT'S POS. I GOT NO RESPONSE FROM CTR. MEANWHILE, JUST BEFORE ENTERING THE CLOUDS, MY MODE S XPONDER BECAME ACTIVE, SHOWING A TARGET ACFT AT 2 O'CLOCK POS, CLBING AND JUST OUTSIDE THE 2 MI CIRCLE. AS I ENTERED THE CLOUDS, I GOT AN AUDIBLE 'TFC' ALERT, INDICATED POS OF -500 FT AND LESS THAN 1 MI. I PERFORMED A CLBING L-HAND TURN UNTIL THE TARGET CLRED. MY PAX LATER STATED THAT THE TARGET TURNED RED AND MERGED WITH THE DEP OF MY ACFT ON THE GPS SIT DISPLAY. AFTER RECOVERING ON COURSE, I MADE 2 ATTEMPTS TO CONTACT ZME THAT WENT UNANSWERED. TO OTHER CALLING ACFT, THE CTLR KEPT TELLING THEM TO STAND BY AS HE WAS EXPERIENCING COMPUTER PROBS. SOME MINS LATE WHEN I WAS GIVEN A FREQ CHANGE, I ASKED THE CTLR ABOUT MY EXPERIENCE AND WAS TOLD THAT HE KNEW NOTHING AS THEY HAD JUST CHANGED CTLRS.

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.