A11 CTLR EXPERIENCED NMAC AT 2000 FT AS FOREIGN ACR FAILS TO COMPLY WITH GAR INSTRUCTIONS.

Narrative

I WAS WORKING THE S RADAR POS WHEN I OBSERVED A B747 ON ABOUT A 1/2 MI FINAL TO RWY 6R AT AN ALT OF 1100 FT. DURING THAT TIME; I WAS WORKING AN IFR C172 AT 2000 FT APPROX 4 MI SE OF ANC ON A TRAINING FLT FROM ANC TO ENA. I COMMENTED TO A CO-WORKER; 'I HOPE THE B747 DOESN'T GO AROUND' BECAUSE OF THE ALT AND PROX TO THE ARPT. THE WX AT THE TIME WAS IFR. I OBSERVED THE B747'S MODE C GO FROM 1100 FT TO 1400 FT AND OBSERVED HIM IN A R TURN TOWARD THE C172. I IMMEDIATELY ISSUED TFC TO THE C172 AND HIS RESPONSE WAS 'WE'RE IMC.' THE B747 WAS 1800 FT AND 1 1/2 MI FROM THE C172 AND I ISSUED AN IMMEDIATE R TURN TO A HDG OF 120 DEGS AND AGAIN ISSUED TFC. THE TARGETS APPEARED TO MERGE. AFTER REPLAYING THE DATA; THE B747 PASSED 400 FT OVER THE C172. ANC TWR WAS COMMUNICATING WITH THE B747. AT THE TIME OF THE INCIDENT; I WAS WORKING LIGHT TFC. I BELIEVE THAT CONFUSION IN THE FLT DECK ABOUT WHAT HDG TO FLY WHEN ISSUING GAR INSTRUCTIONS AND NOT CLR UNDERSTANDING FROM FOREIGN CARRIERS. I DO NOT KNOW FOR SURE; BUT HAD B747'S TCASII BEEN ON; IT WOULD NEVER HAD BEEN THAT CLOSE.