Definition
The cockpit control used by the pilot to command the landing gear to extend (down) or retract (up). It is typically a two-position switch or lever, often shaped like a small wheel, located on the instrument panel within easy reach of the pilot.
Plain English
The switch in the cockpit the pilot moves up or down to raise or lower the landing gear.
Context Anchor
Seen in airplanes with retractable landing gear, especially during after-takeoff and before-landing checklist steps.
Derivation
Gear' is shorthand for 'landing gear,' the wheels and supporting structure the airplane lands on. 'Selector' comes from Latin selectus, meaning 'chosen' — the switch lets the pilot choose between gear up and gear down.
Why Pilots Care
Placing the landing gear in the correct position prevents structural damage on the ground and ensures safe flight performance.
Intuition Check
Do not read gear here as engine gears or general equipment. In this term, gear means landing gear, and the switch commands the system; it is not the indicator that proves the gear has actually moved.
Example Sentence 1
After establishing a positive rate of climb, the pilot moved the gear selector switch to the up position.
Example Sentence 2
On the downwind leg the pilot placed the gear selector switch in the down position and verified three green lights.