What was found
DURING AN ANNUAL INSP, RT WING IB L/E SKIN WAS FOUND CORRODED THROUGH BENEATH STRINGER. A POSSIBLE CAUSE FOR THE EXCESSIVE CORROSION MAY BE WATER SEEPING THROUGH THE AIR INLET HOSE INSTALLED ABOVE THE AFFECTED AREA. THIS WATER ENTERS THROUGH THE L/E AIR INLET AND CREATES RUST IN THE STEEL WIRE WOUND HOSE AND DRIPS RUST CONTAMINATED WATER ON THE WING SURFACE BELOW WHICH MAY ACCELERATE THE CORROSION PROCESS. IT IS RECOMMENDED THAT CLOSE ATTENTION BE PAID TO THAT PART OF THE WING AND TO THE CONDITION OF THE VENT HOSE DIRECTLY ABOVE IT ESPECIALLY IN AIRCRAFT THAT ARE STORED OUTDOORS. APPLYING CORROSION RESISTANT CHEMICAL TO INSIDE OF WING WOULD ALSO HELP SITUATION. (K)