Definition
A fine, closely woven cotton or linen fabric, often treated with a coating or finish, used in aircraft applications such as insulating sleeving over electrical wires and as a backing material for certain coverings.
Plain English
A tight, smooth cotton cloth used in aircraft, most often as an insulating sleeve slipped over wires or as a fabric backing.
Context Anchor
Seen in aircraft maintenance discussions, especially older electrical systems, wire insulation, and protective wrapping.
Derivation
Named after Cambrai, a town in northern France where this fine linen cloth was first made in the 16th century. The fabric became widely used wherever a smooth, tightly woven cloth was needed, which is why it ended up in aircraft as wire insulation and fabric backing.
Why Pilots Care
Pilots rarely handle cambric directly, but mechanics and owners of older or fabric-covered aircraft will encounter it during inspections and electrical repairs. Knowing the term avoids confusion when reading maintenance manuals or service bulletins.
Analogy
Think of cambric as cloth tape that has been stiffened and sealed so it can protect electrical parts, rather than ordinary fabric used for clothing.
Intuition Check
Cambric is not a type of aircraft fabric covering by itself. In this context, it is usually an insulating cloth material used around electrical parts.
Example Sentence 1
The mechanic slipped a length of varnished cambric tubing over the wire bundle to insulate it where it passed through the firewall.
Example Sentence 2
Mechanics in the 1930s often chose cambric because it was light yet strong enough for small training aircraft.