What was found
CAPTAIN REPORTED THAT DURING FLIGHT UNTIL APPROACH, RDMI AND ND WITH DIFFERENCE BETWEEN 30-40 DEGREES. DURING TRANSIT CHECK AT CUU, AHRU NR 1 WAS REPLACED IAW MM 34-21-10, TEST CORRECT. AIRCRAFT WAS DISPATCHED AND RETURNED OF FLIGHT, DFGC AND AHRU NR 2 FAILED AND FLIGHT DIRECTOR BUSES IN BOTH PFD´S AND FMA´S WITHOUT INFORMATION. AFTER LANDING, AHRU INFORMATION WAS RECOVERED, AHRU NR 2 WAS REPLACED, TEST CORRECT. DURING OVERNIGHT SERVICE, DFGC TEST WAS PERFORMED IAW MM 22-01-05, ALL CORRECT.