47-06-11 CESSNA: (Was Service Note 1 of AD-768-4.) Applies Only to 120 and 140 Aircraft Serial Numbers 8001 to 8799, Inclusive.
Compliance required at next periodic inspection and upon each 100 hours of operation thereafter until revised door posts are installed.
Inspect the forward doorposts for cracks, particularly the flange section leading from the post to the instrument panel at the base of the windshield and the post itself below the rivet cluster at the top. All inside fairing attached to the post between the top and the floor should be removed to permit a thorough inspection. Cracks in the above-mentioned flange not over 3/4 inch in length may be repaired by stop-drilling. If there are longer cracks in the flange or any cracks in the doorpost structure itself, the doorpost should be replaced with the later type post, Cessna P/N 0411867-2 and 0411867-3, in accordance with installation instructions supplied by Cessna.
(Cessna Service Letter No. 20 dated October 8, 1946, covers this same subject.)