What was found
FLT 4016 - WHILE SELECTING GEAR DOWN FOR LANDING, CREW DID NOT GET A GEAR DOWN INDICATION FOR THE LEFT MAIN LANDING GEAR. CREW CYCLED THE GEAR SEVERAL TIMES, WITHOUT SUCCESS. CREW ELECTED TO DO AN EMERGENCY LANDING GEAR EXTENSION, STILL DOWN INDICATION FOR THE LT MLG. AIRCRAFT LANDED WITHOUT FURTHER INCIDENT. PIT MAINTENANCE REMOVED AND REPLACED LIGHT BULB IN THE LANDING GEAR SELECT HANDLE. GROUND RUN CHECKED GOOD. AIRCRAFT RETURNED TO SERVICE.