Definition
Fitted covers that block the air intake openings on the front of an engine cowling when the airplane is parked, used to keep out birds, insects, dust, debris, rain, and snow.
Plain English
Plugs or covers placed over the holes in the front of the engine housing while the airplane is parked, so nothing unwanted gets inside.
Context Anchor
Seen during post-flight securing, tiedown, hangaring, and the next preflight inspection before engine start.
Derivation
Cowling' comes from the old word 'cowl,' meaning a hood worn over the head. On an airplane, the cowling is the hood-like covering around the engine. 'Inlet' is simply the opening where air goes in. So the term means covers for the air-entry holes in the engine's hood.
Why Pilots Care
They prevent foreign material from reaching the engine compressor or cylinders, avoiding damage that could require expensive repairs or cause engine failure on the next flight.
Intuition Check
Do not think of cowling inlet covers as a cover for the whole engine. They cover the engine’s air openings, not the entire cowling.
Example Sentence 1
After tying down the airplane, the pilot installed the cowling inlet covers to keep birds from nesting in the engine compartment overnight.
Example Sentence 2
During the preflight walk-around the pilot removed the cowling inlet covers and stowed them before starting the engine.