What was found
FLT 584 - CUN-MEX - DURING FLIGHT THERE WAS 25 DEGREE DIFFERENCE IN HDG RDI OF PILOT AND ALSO ATS 1, AUTO PILOT AND FMA O;S, BOTH DFGC CONFIRMED FAIL IN ATT 1 AND 2, HDG 1 AND 2 AND COMPASS CONTROLLER 1 AND 2. THERE WAS AN INFORMATION LOST IN DFGC 2. BOTH C/B OF AHRS WERE RESET, AND AIRCRAFT WAS DISPATCHED. DURING FLIGHT, CREW REPORTED THE FAIL AGAIN. AT RON MEX 26/27 THE AHRU 1, DFGC 2 AND COMPASS CONTROLLER 2 WERE REPLACED IAW 34-21-10, 22-01-01 AND 34-21-13. AN RTS WAS PERFORMED, COMPUTERS OK IAW MM 22-01-05. (M)