Definition
A self-contained component or sub-assembly designed to function as a single unit within a larger system, and built so it can be removed and replaced as a complete piece rather than repaired in place.
Plain English
A pre-built building block of a bigger system. You swap the whole block out instead of taking it apart and fixing the pieces inside.
Context Anchor
Seen in aircraft and engine maintenance manuals, parts catalogs, and logbook entries when a system or engine section is treated as a replaceable unit.
Derivation
From Latin modulus, meaning 'a small measure' or 'standard unit.' The idea carries over directly: a module is a standard, self-contained unit that fits into something larger.
Why Pilots Care
Modular design is why a turbine engine's hot section or a piece of avionics can often be replaced quickly without tearing down the whole engine or panel. It affects maintenance time, cost, and aircraft availability.
Intuition Check
Do not read module as a school lesson or a computer add-on. In aircraft maintenance, it means a self-contained unit of parts within a larger system.
Example Sentence 1
The technician replaced the engine's compressor module rather than disassembling the entire engine.
Example Sentence 2
Each module undergoes separate testing before the engine is reassembled.