Which fabric type is currently unavailable for use?

Grade A cotton is currently unavailable for use in aircraft fabric covering. This particular fabric was traditionally used in the past due to its favorable properties, such as strength and ease of application. However, over time, modern advancements in aircraft fabrics have led to the adoption of synthetic materials that offer improved performance, durability, and resistance to environmental factors. As a result, many manufacturers and regulatory agencies have shifted towards synthetic options like polyester and nylon, which provide better longevity and resistance to shrinking, stretching, and rot. This shift in preference reflects both technological advancements in material science and the need for enhanced safety and performance in aircraft covering. Consequently, Grade A cotton is no longer a viable option in contemporary fabric covering practices.