Plain English Meaning

The helper parts around the engine — pumps, sensors, ignition gear, and similar items — that the engine needs to operate properly, even though they are not the engine's main moving parts.

Full Definition

The supporting parts attached to an engine that are not part of the core combustion process itself but are required for the engine to run correctly. In a FADEC context, these include items such as fuel pumps, ignition systems, air intake controls, and sensors that the digital control unit monitors and manages.

Context Anchor

Seen in discussions of FADEC and engine systems, especially when describing the parts that support automatic engine control.

Derivation

From the Latin ancillaris, meaning 'serving' or 'helping' (originally referring to a maidservant). In it kept the same idea: parts that serve or support the main item rather than being the main item themselves.