Plain English Meaning

Tiny switches that turn a circuit on or off when something physically pushes against them. The aircraft uses them to know whether a part — like the landing gear or a door — is actually where it should be.

Full Definition

Small electrical switches that open or close a circuit when a mechanical part moves into or out of a specific position. In aircraft, they are commonly used to sense the position of components such as landing gear, flaps, doors, and squat (weight-on-wheels) systems, and to trigger warning lights, horns, or interlocks based on that position.

Context Anchor

Seen during preflight inspections of aircraft systems that use position indications, warning lights, or safety interlocks.