AD 47-43-05

47-43-05 CESSNA: (Was Service Note 3 of AD-768-5.) Applies to 120 and 140 Aircraft Serial Numbers 8001 to 13780, Inclusive.

Inspection required upon each 100 hours of operation until reinforcing channels are installed at all hinge fittings.

Inspect for fatigue cracks in the elevator spar web at the hinges. These cracks start either at the rivets or at an edge of the fitting and progress around the fitting until the elevator breaks loose from the hinge fitting. If cracks less than 1/2 inch in length are found a reinforcing channel, Cessna P/N 0434151 at the outboard hinge or 0434152 at the inboard hinge, should be installed on the aft side of the spar with the flanges riveted between the spar flanges and the skin with two AN 455AD3 rivets per flange. Four AN 442AD4 rivets should be used to attach each fitting to the spar web and reinforcing channel. If any cracks are longer than 1/2 inch the spar should be replaced and the reinforcing channels added.

(Cessna Service Letter No. 46 dated July 31, 1947, covers this same subject.)