Definition
Thin strands of glass or clear plastic used in aircraft construction and systems, most commonly as the light-carrying medium in fiber optic cables or as reinforcing fibers in composite structures. The fibers transmit light along their length by internal reflection, or provide tensile strength when bound in a resin matrix.
Plain English
Very thin, hair-like threads made of glass or see-through plastic. They can carry light from one end to the other, or be combined with resin to make strong, lightweight aircraft parts.
Context Anchor
Seen in aircraft maintenance and systems descriptions, especially where panel lighting, indicators, or light-based signal paths are discussed.
Derivation
Fiber comes from the Latin fibra, meaning a thread or filament. The term simply describes the physical form: long, thin threads. Calling out 'glass or transparent plastic' specifies the materials that allow light to pass through them, which is what makes these fibers useful for both lighting and signal transmission.
Why Pilots Care
Fiber optic bundles are used in some cockpit lighting systems and in modern data buses. Knowing what they are helps when reading maintenance information or troubleshooting lighting and signal issues.
Analogy
Think of a tiny clear straw that guides a small beam of light through it. The light stays inside the strand and comes out at the other end.
Intuition Check
Do not confuse these with structural fiberglass used to strengthen a part. Here the point is not strength; the point is carrying light through clear material.
Example Sentence 1
The cockpit instrument panel uses fibers of glass or transparent plastic material to carry light from a single bulb to several display markings.
Example Sentence 2
The canopy panel was replaced with new fibers of glass or transparent plastic material after it became scratched.