AN ACR FLC DSNDED 1000 FT BELOW THEIR ASSIGNED ALT WHILE ON THE EAU CLAIR 1 STAR TO MSP.

Narrative

RECEIVED CLRNC TO CROSS TWINZ AT 11000 FT. I READ BACK 11000 FT AND SET 11000 FT IN THE ALT ALERTER. I THEN WENT OFF FREQ TO COPY ATIS. ATIS WAS NOT ON THE AIR; PRESUMABLY A NEW TAPE WAS BEING MADE. THE FO BEGAN A DSCNT AND CALLED FOR THE APCH CHKLIST. I RAN THE CHKLIST AND THEN TURNED THE ATIS BACK ON. I COPIED THE NEW ATIS. I NEVER HEARD THE ALT ALERTER CHIME SOUND. AFTER COPYING THE ATIS I PLACED THE CARD ON THE PEDESTAL AND TURNED MY RECEIVER BACK ON. THE FO HAD BEEN MONITORING ATC DURING THIS TIME. WHEN I LOOKED UP WE HAD LEVELED OFF AT 10000 FT. THE ALT ALERT WAS STILL SET AT 11000 FT. I STARTED TO QUESTION THE FO WHEN THE CTR CALLED AND SAID 'SAY ALT.' I RPTED 10000 FT AND WAS INSTRUCTED TO CONTACT APCH CTL. THE FO SAID HE THOUGHT THE ORIGINAL CLRNC WAS TO CROSS TWINZ AT 10000 FT. I'M SURE THE CLRNC WAS TO CROSS AT 11000 FT. HOWEVER; THE CTLR DIDN'T GIVE US ANY ADDITIONAL INSTRUCTIONS AFTER I RPTED LEVEL AT 10000 FT. THE ARR STATES 'EXPECT CLRNC TO CROSS TWINZ AT 10000 FT OR 11000 FT.' MOST OTHER ARRS HAVE 1 SPECIFIC ALT TO CROSS A FIX OR THE ALT IS DESCRIBED AS DEPENDENT ON RWY IN USE. I THINK MY FO MISHEARD THE CLRNC AND I WAS DISTRACTED WAITING FOR THE NEW ATIS.