What was found
ON APPROACH, CREW SELECTED GEAR DOWN, THE RT MAIN GEAR LIGHT DID NOT ILLUMINATE. CREW FOLLOWED CHECKLIST, BLEW DOWN GEAR AND STILL DID NOT RECEIVE PROPER INDICATIONS. CREW USED ROTARY TEST AND GEAR WARNING SYS, NO INDICATION OF UNSAFE CONDITION. CREW DIVERTED FOR MX. CREW DID NOT DECLARE AN EMERGENCY. REPLACED INOPERATIVE BULB WITH NEW, WITH ACFT ON JACKS PERFORMED SATISFACTORY MAIN LANDING GEAR - GEAR SWINGS. ACFT RETURNED TO SERVICE.