Definition
A tube fitted around the exhaust outlet of a reciprocating engine that uses the high-velocity flow of exhaust gases to draw additional cooling air through the engine compartment. The fast-moving exhaust creates a low-pressure region inside the tube, pulling cooling air from around the cylinders and out through the tube along with the exhaust.
Plain English
A tube around the engine exhaust that uses the rushing exhaust gases to suck cooling air past the engine and out the back, helping keep the engine from overheating.
Context Anchor
Seen in aircraft maintenance discussions about engine cooling, cowling airflow, and exhaust system inspection.
Derivation
From 'augment,' meaning to increase or add to (Latin 'augere,' to increase). The tube augments — increases — the airflow through the engine compartment beyond what ram air alone would provide.
Why Pilots Care
Ensures adequate engine cooling during ground operations and low-speed flight; a damaged or missing augmenter tube can lead to overheating and reduced engine life.
Grounding Statement
Picture exhaust rushing through a tube and pulling nearby air along with it, increasing the flow of cooling air through the engine area.
Intuition Check
An augmenter tube does not increase engine power. It increases airflow for cooling by using the motion of the exhaust.
Example Sentence 1
During the inspection, the mechanic checked the augmenter tubes for cracks, since any leak would reduce the cooling airflow they create.
Example Sentence 2
The mechanic replaced the cracked augmenter tube to restore proper engine compartment ventilation.