Definition
An electrical switch with multiple positions, used to choose one of several circuits, sources, or functions for operation. Each position routes electrical current to a different output, allowing the pilot to select which system, indication, or component is active.
Plain English
A switch with several positions that lets you pick which thing it controls or which source it draws from. Turning or moving it sends power down a different path depending on where it is set.
Context Anchor
Seen on cockpit panels, electrical panels, and maintenance diagrams where one control chooses between several system positions or sources.
Derivation
From 'select' (Latin selectus, 'to choose out') plus 'switch.' The name describes the function exactly: a switch that lets you choose between options.
Why Pilots Care
Correct positioning prevents fuel starvation, loss of navigation data, or electrical failures by ensuring the right source is connected.
Analogy
Like the dial on an old car radio that lets you choose one station from many instead of simply turning the sound on or off.
Intuition Check
Do not think of a selector switch as only an on/off switch. Its main job is choosing between positions; each position can make a different circuit, source, or function active.
Example Sentence 1
Before takeoff, the pilot moved the fuel selector switch from LEFT to BOTH so the engine would draw fuel from both tanks.
Example Sentence 2
During the magneto check the mechanic rotated the ignition selector switch to the left position to test only the left magneto.