What was found
ON APPROACH, THE CREW SELECTED GEAR DOWN. THERE WAS NO RIGHT GEAR DOWN LIGHT. THE CREW RAN CHECKLIST. ON ONE GEAR CYCLE, ONLY NOSE INDICATED GREEN. ON LANDING, HAD NOSE GREEN, LEFT GREEN (AFTER MANUAL EXTENSION), RIGHT GEAR LIGHT OUT, RED HANDLE LIGHT ON. RIGHT GREEN CAME ON AFTER LANDING. AIRCRAFT WAS VISUALLY INSPECTED. NO DEFECTS WERE NOTED. MAINTENANCE INSPECTED AND FOUND UP LOCK AND DOWN LOCK SWITCHES DIRTY AND FROZEN WITH ICE. CLEANED SWITCHES, CHECKED RIGGING OF SWITCHES AND LUBRICATED GEAR. COMPLIED WITH GEAR SWINGS. ALL OPS CHECKED GOOD IAW AMM. PERFORMED A SATISFACTORY FUNCTIONAL CHECK FLIGHT. AIRCRAFT RETURNED TO SERVICE.