What was found
(CAN) WHEN SELECTING GEAR DOWN DURING APPROACH RIGHT MAIN LANDING INDICATED UNSAFE. GO-AROUND PERFORMED AND MALFUNCTION CHECKLIST CONSULTED AND PERFORMED FOR ALTERNATE GEAR EXTENSION. ALTERNATE GEAR INDICATION SHOWED 3 GREEN LIGHTS, BUT NORMAL LANDING GEAR INDICATION STILL SHOWED RIGHT MAIN GEAR UNSAFE. PASSENGERS SEATED AROUND PROPELLERS RESEATED FOR PAX COMFORT REASONS. NORMAL LANDING PERFORMED WITH FIRE AND RESCUE ON STANDBY.SAFETY PIN INSTALLED AFTER SHUTDOWN. PASSENGERS DEBRIEFED IN AIRCRAFT AND PAX OFFERED ADDITIONAL DEBRIEFING.R/H MLG DOWNLOCK SENSOR REPLACED. AIRCRAFT RETURNED TO SERVICE.