46-23-05 NOORDUYN: (Was Mandatory Note 1 of AD-2-578-1.) Applies to Army UC- 64, -64A, and -64B Aircraft.
Required at next periodic inspection.
Inspect the trailing edge of the horizontal stabilizer to determine whether or not drain holes are present in the metal trailing edge cover. If the holes are not present, it will be necessary to remove enough fabric to permit inspection of the ribs. Defective or deteriorated wood must be replaced and drain holes, approximately 1/16-inch diameter, spaced to drain all pockets must be drilled.