Aircraft Maintenance Technician (AMT) 40 O&P Practice Test 2026 - Free AMT Practice Questions and Study Guide

Covering aircraft surfaces relies on fabrics that stay stable in service and can be tightened to form a smooth skin. Fiberglass cloth provides excellent dimensional stability and low elongation, which helps resist wrinkles and distortion. When heat-shrinkable polyester fibers are used, applying heat causes the fabric to tighten evenly across the surface, pulling the skin taut and creating a tight, durable covering after finishing. Natural fibers like cotton or wool soak up moisture and change shape with humidity, making them unsuitable for modern, tight fabric coverings. Nylon and aramid fibers are strong but are typically used for structural reinforcement rather than as the primary covering fabric, and silk paired with glass isn’t a standard covering method. This combination of fiberglass and heat-shrinkable polyester fibers best fits the needs of a modern aircraft covering.