Definition
Localized surface damage on a metal component characterized by small cavities or pockmarks, typically caused by corrosion, electrical arcing, or pre-ignition events such as detonation. In an engine context, pitting commonly appears on piston crowns, valve faces, cylinder walls, or spark plug electrodes as evidence of abnormal combustion or material degradation.
Plain English
Tiny pits or holes eaten into a metal surface, leaving it rough and pockmarked instead of smooth.
Context Anchor
Seen during preflight inspection and maintenance discussions, especially when checking propeller blades and exposed engine parts for surface damage.
Derivation
From the English word 'pit,' meaning a small hole or hollow. The term describes the appearance of the damaged surface: covered in small pits.
Why Pilots Care
Pitting weakens the metal and creates stress points that can lead to cracks or blade failure in flight.
Analogy
Pitting is like tiny rust holes starting in the surface of a tool. The tool may still look mostly solid, but the damaged spots show that the surface has begun to break down.
Intuition Check
Do not treat pitting as just a cosmetic blemish. In aviation, pitting means actual loss or damage of material on a surface.
Example Sentence 1
The mechanic found pitting on the piston crown, suggesting the engine had been experiencing detonation.
Example Sentence 2
Mechanics removed the pitted area on the cylinder head before it could develop into a crack.