47-43-06 CESSNA: (Was Service Note 4 of AD-768-5.) Applies to 120 and 140 Aircraft Serial Numbers 8001 to 10209, Inclusive.
Inspection required whenever airplane is tied down in high winds without controls locked and upon each 100 hours of operation until Cessna parts 0422200-2 and 0422200-3 are installed.
Inspect the aileron support ribs for indications of buckling or cracking, particularly in the narrow part of the web at the aft edge of the lightening hole and in the top flange just forward of the doubler plate. Any damaged support rib should be replaced with Cessna parts 0422200-2 (left) and 0422200-3 (right) which are made of 0.051-inch material and have a shorter lightening hole.
(Cessna Service Letter No. 46 dated July 31, 1947, covers this same subject.)