What was found
AT CRUISE, AUTOPILOT A DISENGAGED, CAPTS SPEED & ALTITUDE TAPES DISAPPEARED, SPD & ALT CAUTION LIGHTS APPEARED ON PFD, MACH TRIM FAIL ILLUMINATED ON RECALL AND CAPTAINS PITCH STEERING BAR DISAPPEARED. CONDITION LASTED 15 SECONDS. THIS ANOMOLY OCCURED 5 MORE TIMES IN A 10 MINUTE PERIOD. ALL C/BS CHECKED, IN. AUTOPILOT B & FCC OPERATED OK. SUSPECT FCC A MALFUNCTION. ACFT GROUNDED. REPLACED A FCC COMPUTER IAW MM 22-11-33. OPS CK GOOD, LAND VERIFY TESTS PASS, REF MM 22-11-00. FCC SOFTWARE VERIFIED 74-COL-AC1-07, HGS PASSES ALL TESTS, REF MM 34-36-00.