LESS THAN STANDARD SEPARATION WHEN 2 ACR'S MEET AT HIGH ALT ON OVER OCEAN AIRWAYS AT SAME ALT.

Narrative

AFTER MAKING TURN OVER HENGCHUN VOR VIA G581 TO HONG KONG; ENCOUNTERED OTHER ACFT AT SAME ALT; PROCEEDING SBND ON A577 (XING POINT PARPA INTXN). MADE R TURN OFF ARWY FOR AVOIDANCE; PASSING WITHIN APPROX 2 MI OF OTHER ACFT. THE CTLR ON DUTY WAS THEN CHANGED AND HE SAID THEY HAD AT LEAST 5 MI OF SEP FROM OTHER ACFT. THE OTHER ACFT CONFIRMED THE CLOSE PROX OF THE 2 ACFT AND SAW US TAKE EVASIVE ACTION. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: NO FOLLOW UP CONTACT WAS MADE WITH THE CENTER IN TAIPEI BY TELEPHONE. AFTER THIS INCIDENT TOOK PLACE; WITH A FEMALE CTLR TALKING ON THE RADIO; THE CTLR WAS REMOVED AND A MALE VOICE TOLD THE RPTR THAT THE OTHER ACFT WAS REALLY 5 MI AWAY AND THAT SEP WAS NOT LOST. ON THE RADIO LATER; RPTR HAD A CONVERSATION WITH THE FLT CREW OF THE OTHER ACFT; AND BOTH AGREED THAT SEP WAS NO MORE THAN 2 MI AND POSSIBLY EVEN LESS. RPTR SAID THAT HIS EVASIVE TURN WAS PROBABLY NOT NECESSARY; BUT HE DID NOT FEEL LIKE TAKING CHANCES AT THAT POINT. THE COURSES OF THE ACFT WERE NEARLY PERPENDICULAR; WITH RPTR'S ACFT PROCEEDING EBND AND THE OTHER ACFT SBND.