What aspect of UV damage makes it critical to check fabric regularly?

The critical aspect of UV damage in fabric that makes it essential to check regularly is that it can make the fabric brittle. When fabric is exposed to ultraviolet light over time, the fibers can break down and lose their elasticity. This degradation results in a significant reduction in the structural integrity of the covering material, leading to cracks, breaks, or even complete failure in the fabric. Regular checks can help identify early signs of brittleness, allowing for timely maintenance or replacement to ensure the safety and performance of the aircraft.

While discoloration, changes in weight, or flexibility alterations might occur due to various factors affecting fabric, the brittleness induced by UV exposure is particularly crucial to monitor, as it directly impacts the fabric's ability to withstand operational stresses.