What was found
FLIGHT 474 OGG-OAK - DURING CRUISE FLIGHT, THE CREW NOTED THE NR 2 HF RADIO WOULD NOT CHANNELLIZE. THE CREW CONTINUED TO OAK WITHOUT FURTHER INCIDENT. MAINTENANCE REMOVED AND REPLACED THE NR 2 HF RECEIVER TRANSMITTER PER MM 23-11-21. THE NR 2 HF RADIO PASSED A GROUND OPERATIONAL CHECK. MAINTENANCE ALSO FOUND THE NR 1 HF COUPLER FAULTING AND REMOVED AND REPLACED THE NR 1 COUPLER PER AMM 23-11-61. THE NR 1 COUPLER PASSED A GROUND OPERATIONAL CHECK. THE AIRCRAFT WAS RETURNED TO SERVICE. BOTH HF RADIO SYSTEMS SUCCESSFULLY PASSED FLIGHT VERIFICATION CHECKS ON THE NEXT FLIGHT LEG.