What was found
SBN - FLT 1240 EN ROUTE PIT-SBN, CREW EXPERIENCED TOTAL HYDRAULIC FAILURE. FLIGHT PROCEEDED TO SBN. UPON LANDING, THE NR 3 TIRE BLEW, CAUSING LOSS OF DIRECTIONAL CONTROL OF THE AIRCRAFT. THE AIRCRAFT CAME TO A STOP APPROXIMATELY 6000 FEET DOWN THE RUNWAY AND OFF THE LEFT SIDE OF THE RUNWAY. MAINTENANCE FOUND THE NR 2 ENGINE EDP LEAKING AND THE NR 2 HYDRAULIC SYSTEM EMPTY. IT IS NOT KNOWN WHY THE NR 1 SYSTEM FAILED. THE LOSS OF DIRECTIONAL CONTROL WAS DUE TO ANTI-SKID OPERATION ON LANDING, CAUSING THE TIRE TO BLOW. (M)