What was found
SFO - FLT 483 - DURING APPROACH TO SFO, WHEN LANDING GEAR EXTENDED, NOSE LANDING GEAR UNSAFE LIGHT ILLUMINATED. RECYCLED LANDING GEAR AND NO UNSAFE OR GREEN LIGHT ILLUMINATED. AIRCRAFT PERFORMED TOWER FLY-BY AND VISUALLY CONFIRMED NOSE LANDING GEAR EXTENDED AND DURING SECOND LANDING APPROACH, NOSE LANDING GEAR GREEN LIGHT ILLUMINATED. AIRCRAFT LANDED SFO WITHOUT INCIDENT. REPLACED NOSE LANDING GEAR SWITCH S1-412. ACCOMPLISHED LANDING GEAR RETRACTION CHECK WITH NO DEFECTS FOUND. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)