Definition
Powered mechanically by the airplane's engine, typically through a direct mechanical connection such as a gear, shaft, or accessory drive on the engine itself. An engine-driven component operates only while the engine is running and turning, and its output (pressure, flow, electrical current, etc.) depends on engine speed.
Plain English
The engine itself turns this component and makes it work. If the engine stops, the component stops.
Context Anchor
Seen in landing gear system discussions, especially when describing pumps that use engine power to create the fluid pressure needed to move the gear.
Derivation
Driven comes from the older meaning of drive: to make something move or operate. In machinery, a driven part is one that is powered by another source. In aviation, engine-driven tells you that the airplane's engine is the power source.
Why Pilots Care
Engine-driven components stop working if the engine fails or is shut down, so pilots must know backup options exist for critical systems like hydraulics.
Intuition Check
Engine-driven does not mean the part is inside the engine or that it controls the engine. It means the engine supplies the power that makes that part operate.
Example Sentence 1
On most retractable-gear singles, an engine-driven hydraulic pump supplies the pressure needed to raise and lower the landing gear.
Example Sentence 2
If the engine-driven pump fails, the pilot switches to the electric backup pump for emergency gear extension.