What was found
PILOT OBSERVED A NOSE GEAR UNSAFE (WARNING) INDICATION AFTER TAKEOFF. ATTEMPTED TO RETRACT A SECOND TIME WITH THE SAME RESULTS. THEN EXTENDED THE LANDING GEAR TO A DOWN AND LOCKED CONDITION AND SAFELY RETURNED TO THE AIRPORT WITHOUT FURTHER INCIDENT. AN INSPECTION DISCLOSED THE NOSE GEAR SHOCKSTRUT WAS SEIZED IN AN INTERMIDIATE POSITION, PREVENTING THE NOSE GEAR TO FULLY RETRACT. UPON DISASSEMBLY THE TECHNICIAN DISCOVERED THE SHOCK STRUT BARREL NUT WAS EXTREMELY CORRODED INTERNALLY CAUSING THE SHOCKSTRUT TO SEIZE.