Definition
A fine, flexible filament drawn from molten glass, used in aircraft construction as the reinforcing material in fiberglass composite structures. The fibers are bundled into rovings, woven into cloth, or chopped into mats, then bonded with a resin (usually epoxy or polyester) to form a strong, lightweight, corrosion-resistant material.
Plain English
Very thin strands of glass that are combined with a plastic resin to make a strong, lightweight material used in aircraft parts.
Context Anchor
Seen in aircraft maintenance, especially in composite structure descriptions and fiberglass repair instructions.
Derivation
From 'glass' (the molten silica material) and 'fiber' (a thin thread). The name describes exactly what it is: glass drawn out into thread-thin strands. The surprise is that glass — normally brittle — becomes flexible and remarkably strong when pulled into very fine filaments.
Why Pilots Care
Glass fiber composites allow for lighter aircraft with high strength, improving fuel efficiency and performance while requiring specific repair techniques.
Intuition Check
Do not picture normal window glass. Glass fiber is glass drawn into flexible, threadlike strands that are used to strengthen lightweight aircraft parts.
Example Sentence 1
The aircraft's wingtips and fairings are made from glass fiber laid up with epoxy resin.
Example Sentence 2
Technicians laid up several layers of glass fiber to reinforce the wing spar.