Definition
An aircraft electrical wiring installation method in which individual insulated wires are routed and supported directly along the airframe structure, rather than being enclosed in conduit or bundled inside a protective sheath. The wires are secured at intervals with clamps or ties and rely on their own insulation for protection.
Plain English
A way of running aircraft wires where each wire is laid along the structure on its own, held in place with clamps, instead of being run inside a tube or covered casing.
Context Anchor
Seen in aircraft maintenance, electrical-system inspections, and wire-routing descriptions, especially behind panels, in equipment bays, or near the engine compartment.
Derivation
Called 'open' because the wires are exposed to view and accessible along their run, in contrast to 'closed' or conduit-protected wiring where the conductors are hidden inside a tube.
Why Pilots Care
Open wiring is easier to inspect for chafing, heat damage, and loose clamps during preflight or maintenance checks, but it also means the wires depend entirely on their insulation and routing for protection from abrasion and fluids.
Intuition Check
Do not read open wiring as an open circuit. Open wiring means the wires are physically exposed along their route; it does not automatically mean electricity cannot flow.
Example Sentence 1
During the inspection, the mechanic checked the open wiring along the fuselage for signs of chafing where it passed near the control cables.
Example Sentence 2
Open wiring is common in light aircraft where weight savings are important.