What was found
ON FINAL APPROACH, THE LT MAIN GEAR DOWN INDICATOR DID NOT ILLUMINATE. A GO-AROUND WAS EXECUTED. THE LANDING GEAR WILL NOT EXTEND CHECKLIST WAS COMPLETED, INCLUDING AN EMERGENCY GEAR EXTENSION. LANDING WAS UNEVENTFUL. MX TROUBLESHOT THE DISCREPANCY TO FAULTY LT MAIN GEAR INDICATOR LIGHT BULBS. BULBS WERE REPLACED, N2 SYS SERVICED AND GEAR SWINGS WERE PERFORMED. NO DEFECTS NOTED. ACFT WAS RETURNED TO SERVICE.