Definition
A fine-mesh strainer shaped like a hollow finger or tube, fitted inside a fuel or oil line to trap debris before it reaches downstream components such as carburetors, fuel injectors, or oil passages.
Plain English
A small tube-shaped filter, narrow and closed at one end, that sits inside a fuel or oil line and catches dirt or particles before they can travel further into the engine.
Context Anchor
Seen in fuel system maintenance, tank outlet inspections, and discussions of aircraft fuel strainers or filters.
Derivation
Called a finger screen because of its shape — a narrow, closed-ended cylinder of wire mesh that resembles a finger projecting into the fluid flow.
Why Pilots Care
A clogged finger screen restricts fuel flow and can cause engine power loss or failure.
Analogy
It works like the small screen in a faucet or the strainer in a sink drain: liquid can pass through, but larger bits are held back.
Intuition Check
Do not picture an electronic screen or cockpit display. Here, “screen” means a fine wire filter, and “finger” describes its small projecting shape.
Example Sentence 1
During the annual inspection, the mechanic removed the finger screen from the fuel line and cleaned out the small particles it had collected.
Example Sentence 2
After cleaning the finger screen, fuel flowed freely and the engine regained full power.