Definition
A pilot-operated control that regulates the flow of fuel and air into an engine, thereby controlling the engine's power output. In a piston engine, the throttle moves a butterfly valve in the carburetor or fuel-injection system that varies the volume of the fuel-air mixture entering the cylinders. In a turbine engine, the throttle (often called a power lever or thrust lever) controls the fuel flow to the combustion section.
Plain English
The lever or knob the pilot moves to make the engine produce more or less power.
Context Anchor
A pilot uses the throttle during engine start, taxi, takeoff, climb, descent, landing, and engine checks.
Derivation
From the Old English 'throtian,' meaning to choke or constrict the throat. The connection is direct: opening the throttle widens the passage and lets more mixture through; closing it narrows the passage and chokes the flow, just as a hand at the throat restricts breathing.
Why Pilots Care
Correct throttle use determines engine power for every phase of flight including takeoff, climb, cruise, and landing.
Analogy
Functions like the gas pedal in a car: moving it forward increases power while pulling it back reduces power.
Intuition Check
Throttle does not mean a direct speed control. It controls engine power; the aircraft’s speed also depends on pitch, drag, weight, wind, and flight attitude.
Example Sentence 1
On takeoff, the pilot smoothly advanced the throttle to full power and checked the engine instruments before rotation.
Example Sentence 2
During the descent the pilot eased the throttle back to maintain the target airspeed.