Definition
A form of accelerated, high-temperature attack on the metal parts of a turbine engine, caused when sulfur compounds in the fuel combine with sodium and other contaminants from the air to form molten salt deposits on hot-section components such as turbine blades and nozzle guide vanes. These deposits break down the protective oxide layer on the metal and chemically eat into the underlying material, shortening component life.
Plain English
A type of damage in jet engines where chemicals from the fuel and air combine at high temperatures to form a salty coating that slowly eats away at turbine parts.
Context Anchor
Seen in turbine engine maintenance, especially when discussing inspection of turbine blades, vanes, and other hot-section parts.
Derivation
‘Corrosion’ comes from the Latin corrodere, meaning ‘to gnaw away.’ The word ‘hot’ distinguishes this from ordinary corrosion (like rust) because it only occurs at the high temperatures found inside the turbine section of a running engine.
Why Pilots Care
Unchecked hot corrosion can weaken critical engine parts and lead to in-flight failure or expensive repairs.
Grounding Statement
In a turbine engine, a small amount of salt or other contamination on a very hot part can become an aggressive deposit that attacks the metal surface.
Intuition Check
Hot corrosion does not mean ordinary rust that happens to be warm. It means a specific kind of high-temperature chemical damage, usually involving contaminants on hot engine metal.
Example Sentence 1
The mechanic found pitting on the turbine blades during the hot-section inspection and identified it as hot corrosion.
Example Sentence 2
Using the correct fuel additives helps prevent hot corrosion in the engine's hot section.