What was found
WHEN GEAR LOWERED FOR LANDING, RIGHT MAIN GREEN LIGHT DID NOT ILLUMINATE, WARNING HORN SOUNDED WHEN FLAPS SELECTED TO 30 DEGREES. RECYCLED GEAR PER AMO PROCEDURE. NO CHANGE. ACCOMPLISHED ALTERNATE EXTENSION PROCEDURE, REMOVED AND REPLACED GEAR GREEN LIGHT SWITCH RT. PERFORMED OPERATIONAL CHECK OF LANDING GEAR WITH PLANE ON JACKS. OPERATIONAL INDICATION NORMAL.