Under what condition are anti-tear strips used under wing rib stitching?

• A. Under wing rib stitching when the never-exceed speed is greater than 250 mph.
• B. Under wing trailing edge seams at low speeds.
• C. In cabin panels during turbulence.
• D. On landing gear fairings for aerodynamics.

Answer: (A)

Anti-tear strips reinforce fabric around wing rib joints to prevent tearing under high aerodynamic loads. When the airplane’s never-exceed speed exceeds about 250 mph, the fabric at the rib stitching experiences greater tension, increasing the risk of tear-out along the stitch lines. The anti-tear strip works by spreading that load and preventing the fabric from pulling apart at the rib-stitch location, helping maintain structural integrity at higher speeds. This reinforcement is specific to the rib-stitch area; other locations such as trailing-edge seams, cabin panels, or landing gear fairings aren’t the areas where this strip is applied, especially at lower speeds.