What was found
A/C B27001 DURING CRUISE ON FL370(LOCAL TIME 19:45),"LEFT ENG BLEED OFF", "L PACK"AND L ENG ANTI ICE OFF" LIGHT ON, THEN CAPTAIN FOLLOW THE "QRH" ASKED DECEND TO FL330. ON DECENDING, "RIGHT ENG BLEED" AND "R PACK OFF" LIGHT ON, CAPTAIN ASKED DECEND TO FL290 AGAIN, AT THIS TIME "CABIN ALT INOP" LIGHT ON, THEN CAPTAIN PERFORM THE PROCEDURE OF "CABIN AUTOMATIC INOP" AND ASKED DESCEND TO FL210.ON LOCAL TIME 19:50, CABIN CHIEF REPORTED THAT PAX OXYGEN MASKS ARE DROPPED, THEN CAPTAIN ASKED DESCEND TO FL100. THE AIRPLANE ARE SAFELY LANDING ON KHH AT 20:30 LOCAL TIME. GROUND TEST FOR A/C B27001 AFTER LANDING: ENGINE IDLE: 1). NR 1 AND NR 2 ENGINE "BLEED AIR" NORMAL, (ENGINE BLEED VALVE LIGHT OFF)