Definition
Synthetic fibers made from polyester resin, used in aircraft as a covering material applied over airframe structures (such as fabric-covered wings and fuselages) and as reinforcement in composite layups. Polyester fibers are valued in aviation for their high tensile strength, resistance to rot and mildew, dimensional stability, and long service life compared to older natural-fiber coverings like cotton or linen.
Plain English
Strong, man-made threads made from a type of plastic. In aircraft, they are woven into cloth that covers fabric-skinned airplanes, or used as reinforcing material inside composite parts.
Context Anchor
Seen in aircraft fabric-covering, airframe repair, and material inspection discussions.
Derivation
"Polyester" combines poly- (Greek for "many") and "ester" (a chemistry term for a particular kind of molecular bond). So a polyester is a material built from many ester bonds linked together — a long-chain plastic. Knowing this helps explain why polyester fibers are durable: the long molecular chains give the fiber its strength.
Why Pilots Care
On fabric-covered aircraft, the covering is part of the structure and aerodynamic surface. Knowing the covering is polyester (rather than cotton or linen) tells the pilot or mechanic what inspection criteria, life limits, and repair methods apply.
Intuition Check
Polyester here does not mean ordinary clothing fabric. In this aviation context, it means aircraft-grade synthetic fibers used as a structural covering or repair material where approved.
Example Sentence 1
The wings of the restored Piper Cub were re-covered using polyester fibers, replacing the original cotton fabric.
Example Sentence 2
Polyester fibers were chosen for the interior panel because they resist moisture absorption better than natural fabrics.