AN ACR MD11 FLC HAD A CENTRAL AIR DATA COMPUTER INTERMITTENTLY FAIL CAUSING ALL OF THE WARNING SYS TO ACTIVATE PERIODICALLY AND THE INSTS AND RADIOS TO PARTIALLY FAIL. THE WX WAS BAD AND THEIR DEST WOULD CLOSE AND THEIR FUEL WAS GETTING LOW. THEY FINALLY DECLARED AN EMER AND LANDED DURING A PARTIAL BREAK IN THE WX.

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HOLDING AT CALCO INTXN FL370; 32000 LBS FUEL; ELEVATION LOAD FEEL AND FLAP LIMITER FAULT TO MANUAL AND AUTOPLT AND AUTOTHROTTLE TRIP OFF. AFTER FOLLOWING OUR CHKLIST; SYS RESTORED. AFTER A FEW MINS THE PROB REPEATS. CLRED TO ROME TO HOLD. IN AND OUT OF WX; DSNDING WITH SAME PROB REPEATING. FUEL BECOMING A CONCERN. RADIO BECOMES INTERMITTENTLY INOP OR UNREADABLE IN STATIC. AIRSPD SHOWS OVER 300 KTS THEN 100 KTS. GET ALT ERROR MESSAGE WITH CAPT AND FO ALTIMETER DIFFERING BY 40 FT. FMS LNDG FIELD ELEVATION IN ERROR BY 400 FT. WINDSHEAR WARNING. DURING ALL THIS; A DIVERT TO BIRMINGHAM IS INITIATED. DIRECT ATL IS THEN OFFERED BY ATC AND ACCEPTED; THEN TOLD TO HOLD AGAIN. ANOTHER DIVERT TO BIRMINGHAM; AGAIN OFFERED OF ATL; FUEL STILL A CONCERN. TOLD BY COMPANY THAT WX IS MOVING TOWARD BIRMINGHAM. CONSIDERING THE STILL OCCURRING MULTIPLE FAULTS; RADIO DIFFICULTIES; DECLARED AN EMER WITH REQUEST DIRECT ATL WITH MONITORING OF ALT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR IS A FO ON THE MD11 AND THIS WAS THE FIRST CENTRAL AIR DATA COMPUTER FAILURE HE HAS HEARD OF DURING HIS 3 YRS ON THE ACFT. HE SAID THE MOST DISCONCERTING PART OF THE EXPERIENCE WAS THAT THE COMPUTER WOULD START TO WORK AS THE FLC WAS ABOUT HALF THE WAY THROUGH THE CHKLIST; ONLY TO START FAILING AGAIN AFTER THEY STARTED ON ANOTHER TASK. ALSO DURING THE FAILURES; ALL OF THE WARNING SYS IN THE COCKPIT WOULD SOUND AND ALL THE LIGHTS WOULD ILLUMINATE. THESE FAILURES CONTINUED THE REST OF THE FLT ACCORDING TO THE RPTR. HE SAID THAT HE WENT TO THE MAINT FACILITY THE NEXT DAY AND A TECHNICIAN APPARENTLY TOLD HIM THAT THE #2 CADC COMPLETELY FAILED AND THAT THIS FAILURE ALSO AFFECTED THE #1 CADC. THE RPTR SAID THAT HIS UNDERSTANDING OF THE SYS WAS THAT THE CADCS WERE ISOLATED FROM EACH OTHER AND ONE COULD NOT ADVERSELY AFFECT THE OTHER. SUPPLEMENTAL INFO FROM ACN 375656: BEGAN TO GIVE US INTERMITTENT FAILURES WHICH COULD LEAD TO LOSS OF ALL NAV; PARTIAL FLT INSTS AND FLT CTL FEEL. AN EMER WAS DECLARED TO GO TO ATL WITHOUT FURTHER PROBS. MAINT FOUND AT LEAST 39 FAULTS RECORDED IN THE COMPUTER SYS.