Definition
An electrical wire surrounded by a conductive metal sleeve, usually a braided or foil layer, that is grounded to block external electromagnetic interference from reaching the inner conductor and to prevent signals inside the wire from radiating outward.
Plain English
A wire wrapped in a thin metal sleeve that acts like a barrier, keeping outside electrical noise out and stopping the wire's own signals from leaking and disturbing nearby equipment.
Context Anchor
Seen in aircraft wiring diagrams, radio and antenna wiring, instrument wiring, and maintenance troubleshooting for electrical noise or weak signals.
Derivation
From the word 'shield', meaning a protective barrier. The metal layer literally shields the inner wire from electrical interference, the same way a physical shield blocks something from getting through.
Why Pilots Care
Unshielded wires can pick up interference that corrupts critical navigation and radio signals, creating safety risks during flight.
Intuition Check
Shielded does not mean the wire is armored against physical damage. Here it means the wire has a metal layer that helps protect the electrical signal from interference.
Example Sentence 1
The audio harness uses shielded wire to keep engine ignition noise out of the intercom system.
Example Sentence 2
All sensitive sensor leads were routed using shielded wire and grounded at one end per the wiring diagram.