48-25-03 CESSNA: Applies to All 120 and 140 Aircraft.
Inspection required each 100 hours of operation.
Inspect wing drag wire system for loose or broken drag wires and inspect ribs for damage. Inspection openings should be installed aft of the rear spar just inboard of Rib 5 and just outboard of Rib 10 if not already installed. Drag wires should be rerigged if loose, or replaced if broken, and drag ribs should be repaired or replaced if buckled. No. 6 drag wires in the outer wing panel found broken are to be replaced with No. 8. Buckling of the intermediate rib flanges at the spar cutouts does not render the wing unairworthy; however, reinforcement with Cessna P/N 10004-58 is recommended. If the flanges are cracked the reinforcement should be installed.
(Cessna Service Letters 27 and 39 cover this same subject.)