Definition
A common electrical conductor, usually a metal strip or rigid bar, to which multiple electrical circuits are connected. In an aircraft, the bus bar receives power from sources such as the battery, alternator, or generator, and distributes it to the various circuits that supply individual electrical components.
Plain English
A central piece of metal inside the aircraft's electrical system that acts as a shared connection point. Power comes into it from the battery or alternator, and from there it gets sent out to all the things that need electricity — radios, lights, instruments, and so on.
Context Anchor
Seen in aircraft electrical system descriptions, wiring diagrams, and discussions of what happens when one electrical power path feeds several items.
Derivation
From 'bus,' shortened from the Latin 'omnibus' meaning 'for all,' combined with 'bar' meaning a solid strip of metal. The name reflects its function: a single bar that serves all the connected circuits.
Why Pilots Care
Knowing how bus bars work helps identify which systems lose power during electrical failures and supports safe load management decisions.
Analogy
Think of a power strip with many outlets. The strip itself is one piece of metal carrying current; everything plugged into it draws from that shared source.
Intuition Check
“Bus” does not mean a vehicle here. In this term, a bus is a shared electrical path that supplies power to multiple places.
Example Sentence 1
When the alternator fails, the battery continues to feed the main bus bar until it is depleted.
Example Sentence 2
During an alternator failure, the battery continued supplying the essential bus bar to keep critical instruments running.