MIL REFUELER CLRED INTO MOA BUT BLOCK ALT NEVER COORD WITH CTR.

Narrative

WE CLRED INTO THE BRISTOL MOA BY LAX AT 15000 FT MSL. CHKING INTO THE AREA THE CTLING AGENCY CALL SIGN 'CHIEFTAN;' TOLD US TO OP 15000 FT TO FL220. AFTER ABOUT 1 HR ON STATION AS THE AIRBORNE REFUELER WE CLBED FROM 15000 FT TO FL180 TO REMAIN CLR OF CLOUDS AS REQUIRED BY OUR MISSION. AFTER BEING AT FL180 FOR APPROX 30 MIN WE WERE INFORMED BY LAX THAT WE SHOULD NOT HAVE LEFT 15000 FT MSL WITHOUT HIS PERMISSION. ONCE BACK ON THE GND WE PHONED LAX AND CHIEFTON THE CTLING AGENCIES INVOLVED. WE LEARNED THAT EVEN THOUGH THE BRISTOL MOA WE WERE OPERATING IN WAS SCHEDULED FOR OUR USE AND WE HAD CHKED IN WITH BOTH AGENCIES; LAX HAD NOT ACTIVATED THE RESERVED BLOCK ALT 15000 FT TO FL220 AS CHIEFTON HAD LED US TO BELIEVE BY THEIR INITIAL RADIO CALL. THIS MISUNDERSTANDING IS HAZARDOUS BECAUSE WE WERE VARYING OUR ALT TO MAINTAIN VMC WITHOUT INFORMING ZLA WAS NOT. LAX MIGHT HAVE SENT ACFT THROUGH THE MOA RESULTING IN A MID AIR. TO CORRECT THIS; LAX SHOULD AUTOMATICALLY BLOCK THE ENTIRE MOA AS SOON AS A PARTICIPATING MIL ACFT CHKS INTO THE WORKING AREA. ESPECIALLY IF ALL CONCERNED KNOW THAT THE AREA AND ALT BLOCK ARE RESERVED IN ADVANCE AND THE AIR CREWS ARE LED TO BELIEVE THEY 'OWN' THE MOA.