OPERROR PLTDEV BTWN ACR X AND ACR Y.

Narrative

IN SUM: ACR X ON A FLT FROM OSAKA TO HNL AT FL330 OBSERVED 2 ACFT ON THE TCASII DISPLAY WHILE STILL WITHIN RADAR COVERAGE OF TOKYO CTR. 1 ACFT WAS CLBING THROUGH FL280 AND THE OTHER WAS INDICATING FL370. AFTER LISTENING TO THE EXCHANGE OF XMISSIONS BTWN THE CTLR AND THE FLC OF THE ACFT THAT WAS CLBING. THE RPTR WAS ABLE TO DETERMINE THAT THE CLBING ACFT WAS ACR Y SINCE THE CTLR HAD POINTED OUT THE RPTR'S ACFT AS BEING AT THE 3 O'CLOCK POS AT A DISTANCE OF 17 MI. THIS COINCIDED WITH THE TCASII TARGET POS DISPLAYED. THE CTR CTLR HAD ASKED ACR Y THEIR CLB RATE AND WAS INFORMED THAT IT WAS 500 FPM. RPTR WAS ABLE TO DETERMINE THAT THIS WAS NOT TRUE AS INDICATED BY THE TCASII WHICH RPTR FELT WAS ABOUT 100 FPM. THE CTLR REQUESTED ACR Y TO MAKE A 360 DEG TURN 3 TIMES AND EACH TIME REQUESTED THEIR ALT. SUBSEQUENTLY; RPTR LOST THE TCASII TARGET AND IMMEDIATELY TURNED ON THE WX RADAR TO RELOCATE THE TARGET. THE FLC OF RPTR'S ACFT ATTEMPTED TO VISUALLY SIGHT ACR Y AND CONTINUED TO MONITOR THE WX RADAR TO FLT FOLLOW THE ACR Y AS IT APCHED TO ABOUT 5 MI OF THEIR ACFT. THE TCASII TARGET FOR ACR Y REAPPEARED; INDICATING THE ACFT AT FL350; BTWN THEIR 10-11 O'CLOCK POS. AT THIS TIME THE ANTI-COLLISION LIGHTS WERE VISIBLE. EARLIER; ABOUT THE TIME RPTR LOST THE TCASII TARGET FOR ACR Y; BOTH ACFT HAD BEEN SWITCHED TO ENRTE RADIO. AT THAT TIME; RPTR ATTEMPTED TO CONTACT ACR Y BUT GOT NO RESPONSE EVEN THOUGH THEY COULD HEAR COM BTWN ENRTE RADIO PERSONNEL AND ACR Y. AFTER FLT FOLLOWING COM AND TCASII ALT OF ACR Y TO HNL; ACR Y LANDED IMMEDIATELY BEHIND RPTR'S ACFT.