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.