Definition
The formation and collapse of vapor bubbles in a liquid caused by a localized drop in pressure below the liquid's vapor pressure. In aircraft systems such as hydraulic pumps and fuel pumps, cavitation occurs when the pump tries to move liquid faster than it can flow in, causing the liquid to momentarily vaporize. When these vapor bubbles reach a higher-pressure area, they collapse violently, eroding metal surfaces and degrading pump performance.
Plain English
Tiny bubbles form inside a liquid when the pressure drops too low, and then those bubbles snap shut with enough force to chew up the metal parts around them. It usually happens inside pumps when liquid can't get in fast enough to keep up.
Context Anchor
Seen in aircraft hydraulic and fuel system maintenance, especially when discussing pumps, fluid flow restrictions, or low pressure at a pump inlet.
Derivation
From the Latin cavus, meaning 'hollow.' The bubbles are literally hollow cavities forming inside the liquid, which is where the name comes from.
Why Pilots Care
Cavitation reduces pump output, can starve an engine of fuel, and progressively destroys impeller blades through erosion.
Grounding Statement
Picture a pump trying to draw liquid from a nearly empty tank: instead of smooth flow, it pulls in vapor pockets that collapse with tiny but damaging shocks against the pump's internal surfaces.
Intuition Check
Cavitation is not simply air leaking into a system. It is vapor bubbles forming from the liquid itself because local pressure has dropped too low.
Example Sentence 1
The technician suspected cavitation in the hydraulic pump after noticing pressure fluctuations and a whining noise during ground checks.
Example Sentence 2
A clogged inlet screen allowed cavitation to develop in the hydraulic pump during ground checks.