Definition 1 of 2
Plain English Meaning
The smooth, shaped covering that wraps around an engine and the equipment attached to it, holding everything in place and letting air flow around it cleanly.
Full Definition
A streamlined enclosure that houses an aircraft engine and its accessories, separate from the main fuselage. The nacelle provides aerodynamic shaping, structural mounting for the engine, cooling airflow paths, and fire protection, and it is typically attached to a wing, pylon, or tail structure.
Context Anchor
Pilots encounter engine nacelles during preflight inspection, aircraft walkaround, maintenance discussions, and aircraft systems descriptions.