What was found
THE NOSE GEAR RED UNSAFE LIGHT REMAINED ILLUMINATED AFTER TAKEOFF. ABNORMAL PROCEDURES WERE COMPLIED WITH, BUT THE LIGHT REMAINED ILLUMINATED. THE AIRCRAFT WAS RETURNED TO LAS WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE FOUND KNEE HINGE BOLT LOOSE AND RETRACT CYLINDER LEAKING. THE KNEE HINGE BOLT WAS TIGHTENED AND THE RETRACT CYLINDER WAS REPLACED. IN ADDITION, THE UPLOCK SENSOR WAS REPLACED, THE NOSE GEAR WAS SWUNG AND OPERATION CHECKED GOOD.