AD 58-17-02

58-17-02 CURTISS-WRIGHT: Applies to all C-46 Series aircraft including the Models C-46R and C-46/CW20-T aircraft.

Compliance required as noted.

Due to recurrent fatigue cracking on the horizontal tail surfaces, the following inspections must be accomplished:

1. Conduct a daily visual external inspection of the horizontal tail surfaces for cracks with especial reference to cracks developing in the skin and ribs in the area of the elevator balance weights and the elevator hinge cutouts.

2. A detailed visual inspection of the horizontal tail surfaces must be conducted at intervals not to exceed 100 hours' time in service. Particular attention should be paid to cracks developing in the area of the balance weights on the elevator, elevator nose ribs, elevator main spar, and elevator and stabilizer hinge ribs.

3. Any cracks found must be repaired in accordance with the structural repair manual or other approved repair method prior to the next flight. Stop-drilling of cracks is not considered a repair but may form part of a repair.

To facilitate inspection, the horizontal stabilizer may be modified in accordance with L.B. Smith Aircraft Corporation Drawing No. 5.040.02, or approved equivalent.

To provide access to the elevator interiors for visual inspection, access holes may be added in the elevator skin as shown on Riddle Airlines Incorporated Service Bulletin No. RSB-C- 46-8.

Revised July 11, 1961.