Definition
A material that resists the flow of electric current, used to block or contain electricity rather than conduct it. In aircraft construction, insulators separate conductive parts so that current follows only the intended path.
Plain English
Something that electricity cannot easily pass through. It is used to keep electric current out of places it should not go.
Context Anchor
Seen in aircraft electrical systems and lightning strike protection discussions, especially when describing which parts carry electricity and which parts separate or protect them.
Derivation
From the Latin insulare, meaning 'to make into an island.' An insulator effectively turns a part into an electrical island — current cannot reach it or leave it through the insulating material.
Why Pilots Care
Aircraft use insulating materials to direct lightning current safely along the exterior and avoid damage to internal systems or fuel tanks.
Analogy
An electrical insulator is like the plastic handle on a tool. The metal part may carry electricity, but the plastic handle helps keep that electricity away from your hand.
Intuition Check
Do not think an electrical insulator is an absolute shield against all electricity. A strong enough lightning strike can jump across or damage materials that normally insulate.
Example Sentence 1
The rubber coating on the wiring acts as an electrical insulator, keeping the current inside the wire and away from the airframe.
Example Sentence 2
Inspect wiring harnesses to confirm that every electrical insulator remains intact and free of cracks.