What was found
ON APPROACH TO GUM WHEN GEAR WAS LOWERED, THE RIGHT MAIN GEAR INDICATED UNSAFE ON BOTH THE PILOT'S AND SECOND OFFICER'S PANELS. TRIED MANUAL EXTENSION, INDICATION REMAINED UNSAFE. ACCOMPLISHED LOW ALTITUDE FLY-BY. DECLARED AN EMERGENCY AND LANDED WITHOUT INCIDENT. REPLACED THE RIGHT MAIN LANDING GEAR DOWNLOCK PROXIMITY SENSOR AND TARGET. ALSO REPLACED THE RIGHT MAIN LANDING GEAR RETRACT ACTUATOR AND PROXIMITY SENSOR, OPERATIONAL CHECK OK.