Definition
A material that strongly resists the flow of electric current. Insulators are used to separate conductors and prevent unwanted electrical paths, protecting both the circuit and the people working on it. Common aviation insulators include rubber, plastic, glass, ceramic, and certain varnishes used on wire coatings and component housings.
Plain English
A material that electricity cannot easily pass through. It is used to keep current where it belongs and stop it from going where it shouldn't.
Context Anchor
Seen in aircraft wiring, electrical troubleshooting, battery work, ignition systems, and component installation.
Derivation
From Latin insula, meaning 'island.' An insulator makes an electrical 'island' by isolating one conductor from another, just as an island is separated from surrounding land by water.
Why Pilots Care
Damaged or degraded insulation is a common cause of electrical faults, shorts, and in-flight fires. Recognising what insulators do helps when inspecting wiring, troubleshooting, or understanding maintenance findings.
Analogy
An insulator is like the plastic coating on a household power cord. The metal inside carries the electricity, while the outside covering helps keep the electricity away from your hand and nearby objects.
Intuition Check
Do not think of an insulator only as something that keeps heat in or out. In this aircraft maintenance context, it usually means something that blocks or resists the flow of electricity.
Example Sentence 1
The technician replaced a section of wire after finding the rubber insulator had cracked and exposed bare copper.
Example Sentence 2
The battery compartment uses insulators to separate positive and negative terminals.