FLT CREW OF MD11 EXPERIENCE FAILURE OF CAPT'S CADC IN IMC SHORTLY AFTER TKOF. FO ASSUMES CTL FOR RETURN LAND.

Narrative

SHORTLY AFTER TKOF; EXPERIENCED A LOSS OF AIRSPD; ALT; VERT SPD AND POSSIBLE ATTITUDE. TRANSITIONED IMMEDIATELY TO STANDBY INSTS. IMC AT THIS TIME AND BROKE OUT OF THE LOW CLOUD AND WAS ABLE TO MAINTAIN ATTITUDE. INITIAL CLRNC WAS 7000 FT ON DEP AND MAY HAVE POSSIBLY EXCEEDED THAT AND POSSIBLY EXCEEDED 250 KTS AIRSPD. ACFT WAS CONTINUALLY DISPLAYING NUMEROUS FAULTS AND FAILURES; MASTER WARNING AND MASTER CAUTION. WEREN'T SURE WHAT THE PROB WAS. DID THE AIRSPD LOSS; ERRATIC UNRELIABLE CHKLIST AND DETERMINED CAPT'S CADC WAS FAULTY. XFERRED CTL OF ACFT TO FO FOR AN UNEVENTFUL APCH AND LNDG ON RWY 26L IN ONTARIO. HAD A JUMP SEATING MD11 CAPT ON BOARD WAS ASSISTED WITH CHKLISTS AND OTHER TASKS. MAINT DETERMINED THAT THERE WAS BLOCKAGES IN THE CAPT'S AND FO'S PITOT TUBES ALONG WITH A FAILURE OF L CADC. ACFT WAS SUBSEQUENTLY REPAIRED AND OPERATED NORMALLY FOR THE NEXT FLT SEGMENT. I BELIEVE WE TOOK THE CORRECT INITIAL ACTION BY TRANSITIONING IMMEDIATELY TO THE STANDBY INSTS; AND LUCKILY; WERE ABLE TO MAINTAIN ATTITUDE AND ALT; AND AIRSPD UNTIL WE BROKE OUT OF THE WX.