Definition
The electrical wiring, connectors, switches, and protective devices that supply power from the aircraft's electrical system to the landing light(s). On certificated aircraft, this circuit is one of the items a pilot-owner is permitted to repair or replace as preventive maintenance under FAR Part 43, Appendix A.
Plain English
The wires and connections that carry electricity to the landing light. The pilot-owner is allowed to fix or replace this wiring as a simple maintenance task, rather than needing a mechanic to do it.
Context Anchor
Seen in preventive maintenance discussions, especially when checking or repairing a landing light that does not turn on, flickers, or has a damaged connection.
Derivation
Circuit comes from a Latin idea meaning “to go around.” That helps here because an electrical circuit must make a complete path for electricity to leave the power source, pass through the light, and return.
Why Pilots Care
Functional landing light wiring circuits are required for safe night operations and to meet regulatory lighting standards.
Intuition Check
Do not think of the circuit as only the visible wire near the light. In this context, the circuit means the whole electrical path that lets the landing light receive power and operate.
Example Sentence 1
After noticing the landing light flickered on short final, the owner-pilot inspected the landing light wiring circuits during the next preflight and found a loose connector behind the panel.
Example Sentence 2
A break in the landing light wiring circuits prevented the lights from illuminating on final approach.