A DSNDING FALCON 2000 FLC MISINTERPS THE CLRNC TO FL390 AS 'FL290.' THEIR INCORRECT READBACK WAS MISSED BY THE ARTCC RADAR CTLR AT ZKC; MO.

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ON APR/XA/00; APPROX 120 MI FROM HUT ARPT AT A CRUISE ALT OF FL430. WE ASKED FOR A DSCNT FROM ZKC AND THE CTLR (FREQ WAS NOT NOTED) GAVE US A HDG TO FLY FOR OUR DSCNT; WHICH WAS 15 DEGS TO THE R. AFTER OUR TURN; THE CTLR GAVE US THE INSTRUCTION TO 'DSND AND MAINTAIN FL290.' WE IMMEDIATELY READ BACK 'DSND AND MAINTAIN FL290; CALL SIGN.' WE WET OUR ALT ALERTER TO FL290 AND BEGAN OUR DSCNT. PASSING THROUGH FL380; THE CTLR ASKED US TO STATE OUR ASSIGNED ALT. WE STATED THAT OUR ASSIGNED ALT WAS FL290. HE ANSWERED 'NEGATIVE; YOUR ASSIGNED ALT WAS FL390; MAINTAIN FL370.' WE BEGAN AN IMMEDIATE LEVELOFF AND WERE ABLE TO LEVEL AT FL370. THE CTLR ASKED ONCE AGAIN IF WE WERE MAINTAINING FL370 AND WE ANSWERED THAT WE WERE. NO OTHER INSTRUCTIONS NOR QUERIES WERE ISSUED BY THE CTLR. A SUBSEQUENT FREQ CHANGE WAS GIVEN SHORTLY THEREAFTER; AND THE NEXT CTLR (ALSO ZKC) GAVE US A DSCNT CLRNC TO FL240. WHILE IT DOES NOT SEEM THAT THERE WAS AN IMMEDIATE THREAT TO ACFT SAFETY; I WANTED IT TO BE KNOWN THAT THERE IS NO DOUBT THAT THE INITIAL DSCNT FROM THE CTLR WAS GIVEN TO FL290; AND THAT EXACT CLRNC WAS READ BACK TO THE CTLR AS FL290 AND NO QUERY WAS THEN GIVEN BY THE AIR TFC CTLR. UNDERSTANDING THAT THE FAA DOES NOT HOLD AIR TFC CTLRS LIABLE FOR ANY READBACK ERRORS; CORRECTIVE ACTION IN THIS CASE SHOULD BE THAT CTLRS BE MORE ATTENTIVE TO THE READBACK OF INSTRUCTIONS. SOMETIMES RADIO INTERFERENCE CAN CAUSE MISUNDERSTANDINGS AND BOTH PLTS AND AIR TFC CTLRS SHOULD VERIFY ANY INSTRUCTIONS THAT MAY BE MISCOMMUNICATED.SUPPLEMENTAL INFO FROM ACN 469666: WE WERE PROCEEDING DIRECT TO HUT AT FL430. THERE WERE 2 CAPTS ON THIS FLT; BUT I WAS THE DESIGNATED PIC AND OCCUPYING THE R SEAT ON THIS LEG. ATC GAVE US A 10 DEG OR 15 DEG TURN TO THE R FOR OUR DSCNT. ABOUT THAT TIME I ANNOUNCED TO THE OTHER PLT THAT I WAS GOING TO LEAVE THE FREQ TO GET THE ATIS FOR HUT. A SHORT TIME LATER I RETURNED TO CTR FREQ JUST IN TIME TO HEAR THE TAIL END OF A DSCNT CLRNC BEING ISSUED TO US BY ATC. ALL I HEARD FROM THE CTLR WAS THE 'NINE ZERO' PORTION OF THE CLRNC; BUT DID HEAR THE OTHER PLT CLRLY READ BACK 'DSND TO FL290' AS HE SIMULTANEOUSLY SET FL290 INTO THE ALT PRESELECTOR. AT NO TIME DURING THIS EVENT DID WE DETECT EITHER VISUALLY OR BY TCASII ANY CONFLICT WITH OTHER AIR TFC IN THE VICINITY.