ACR ENTERS ADJACENT FACILITY AIRSPACE AT WRONG ALT IN OCEANIC NON RADAR ENVIRONMENT

Narrative

THIS INCIDENT INVOLVED AN AIRSPACE DEV WHERE AN ACFT ENTERED ANOTHER CTL FACILITY'S (TOKYO CTR) AIRSPACE AT AN ALT OTHER THAN WHAT WAS COORDINATED. THE INCIDENT INVOLVED ACR X; A WDB; ENRTE FROM PGSN TO RJAA VIA A337. THE ACFT WAS TRANSFERRED TO OAK ARTCC FROM GUAM CERAP; PROCEEDING PGSN DIRECT TEGOD A337 CLBING TO CROSS 20 DEG N LATITUDE AT FL390. THE CTLR THAT I RELIEVED TOOK THE TRANSFER AND WROTE THE WRONG ALT ON THE FLT PROGRESS STRIP. HE INDICATED THAT ACR X WAS CLBING TO CROSS 20 DEG N LATITUDE AT FL350. AT ABOUT THIS TIME; I WAS SENT TO RELIEVE THIS CTLR SO THAT HE COULD HAVE A BREAK. DURING THE RELIEF BRIEFING; WHEN WE DISCUSSED THIS ACFT; THE CTLR INFORMED ME THAT ACR X WAS CLBING TO CROSS 20 N LATITUDE AT FL350; JUST TO MAKE SURE I HAD IT CORRECTLY; I QUESTIONED THE ALT CLBING TO AND AGAIN; I WAS TOLD THAT ACR X WAS CLBING TO CROSS 20 DEG N AT FL350. AFTER I ASSUMED THE SECTOR; I CALLED TOKYO CTR WITH A TRANSFER ON ACR X AT TEGOD TIME X17Z AT FL350. DUE TO THE SHORT DISTANCE BTWN GUAM'S AIRSPACE AND TOKYO'S AIRSPACE; MANY TIMES OAK ARTCC DOES NOT RECEIVE ANY PROGRESS RPTS. SO THE FIRST POINT THAT THE PLT RPTED WAS TEGOD. AT X34Z; TOKYO CTR CALLED TO VERIFY THE ASSIGNED ALT OF ACR X AS FL350 AND INDICATED THAT THE ACFT WAS AT FL390. I THEN CALLED GUAM CERAP TO VERIFY THE ASSIGNED ALT. THE CTLR SAID THAT THE ACFT WAS ASSIGNED TO CROSS 20 DEG N LATITUDE AT FL390. AT THIS TIME; I CALLED TOKYO AND ADVISED THEM THAT THE ACR X WAS IN FACT ASSIGNED FL390. AT THE TIME OF THE INCIDENT; SECTOR OC5 AT OAK ARTCC WAS EXTREMELY BUSY WITH HVY TFC (25 OR MORE ACFT) AND A VERY HIGH COMPLEXITY LEVEL. THE CORRECTIVE ACTION WOULD HAVE BEEN TO HAVE THE FIRST CTLR INDICATE THE PROPER ALT ON THE FLT PROGRESS STRIP.