MIL PLT DESCRIBED CONFLICT EVENT WHEN UNKNOWN/UNREPORTED ACFT ENTERED BLOCKED REFUELING AIRSPACE.

Narrative

LEARJET CROSSED WITHIN 4.79 NM OF ACFT Y (T1) AT FL250 (1000 FT BELOW T1 ALT; BUT STILL IN THE AR BLOCK) AS ACFT XX TRANSITIONED FROM T2 TO T1. ACFT X HAD NO SITUATIONAL AWARENESS ON THE LEARJET TFC AS ATC RADIO WAS TURNED DOWN AND NOT UPDATED AFTER CLRED TO TANKER FREQ AND IFF WAS IN STANDBY PER AIR REFUELING PRE-CONTACT CHKLIST. T1 AND T2 HAD LIMITED SITUATIONAL AWARENESS ON THE LEARJET FROM AT AND TCAS; BUT DID NOT PASS TO ACFT X. FOR THE TRANSITION FROM T1 TO T2; MIL HVY JET FORMATION AR PROCS CALL FOR R1 TO DSND 500 FT BELOW T1 ALT; MOVE IN LINE AND CLB VISUALLY. THIS SEEMS TO BE THE EXACT MOMENT WHEN THE LEARJET PASSED UNDERNEATH ACFT X (FL255) AND T2 (FL265); HOWEVER; I CAN'T BE SURE. ONCE IN LINE OF T1; ACFT X LOST SIGHT DUE TO WX; CALLED BLIND; DSNDED TO FL250 AND STOPPED CLOSURE OUTSIDE OF 1 NM USING A/A TACAN AND WX RADAR AS PRIMARY SITUATIONAL AWARENESS TOOLS. THIS HAPPENED SOMETIME SHORTLY AFTER LEARJET CROSSED; BUT NOBODY (ESPECIALLY ZAN) WAS AWARE OF ACFT X'S EXACT POS DUE TO LACK OF SQUAWK DURING MARSA OPS. AFTER BREAKING OUT OF THE WX WITH T1 IN SIGHT AGAIN -- WE CONTINUED CLOSURE NORMALLY FOR THE REST OF THE TRACK UNAWARE OF THE POSSIBLE MIDAIR.