When evaluating fabric strength for re-covering, which two performance parameters primarily determine the required strength?

• A. Never-exceed speed and wing loading
• B. Engine horsepower and propeller diameter
• C. Maximum takeoff weight and altitude
• D. Tail number and color

Answer: (A)

The main idea is that fabric strength for re-covering is determined by the loads the wing skin must carry during operation. Those loads come from aerodynamic forces as the aircraft flies at its limit and from the weight the wing must support. The key indicators of those loads are the never-exceed speed, which sets the maximum dynamic pressure the wing experiences, and the wing loading, which is the weight supported per unit wing area. Higher speed increases the aerodynamic forces on the fabric, and higher wing loading increases the stress the skin and underlying structure must withstand.

Engine horsepower and propeller size mainly affect thrust and performance, not the direct fabric loads. Altitude can alter air density and performance but isn’t as direct a determinant of fabric strength as the speed and weight-related loading. Tail number and color have no bearing on the fabric’s structural requirements.