What was found
LEFT SIDE WALL WAS REMOVED TO INSTALL RADIO EQUIPMENT. THE VERTICAL DUCT FOR AIR TO OVERHEAD WEMAC SHOWED DEFINITE SIGNS OF BURNING AND SEVERE DETERIORATION. UPON FURTHER EXAMINATION, THE OXYGEN LINE CROSSING DUCT HAD SEVERE CORROSION WHERE CONTACT BETWEEN THE LINE AND DUCT HAD OCCURRED, AND HAD 2 HOLES IN THE LINE. WHEN THE OXYGEN WAS TURNED ON, OXYGEN WAS SPRAYED ON DUCT AND BEHIND SIDEWALL OF AIRCRAFT. MANUFACTURED NEW LINE TO REPLACE CORRODED LINE. INSTALLED NEW DUCT. SPIRAL WRAPPED OXYGEN LINE WHERE CONTACT WITH DUCT OCCURS.