Definition
A crack or break in a propeller blade, hub, or related structural component, typically caused by stress, fatigue, ground strikes, foreign object damage, or undetected internal flaws. A prop fracture is a serious airworthiness condition that can lead to blade separation, severe vibration, or loss of engine power in flight.
Plain English
A crack or break in the propeller. Even a small one is dangerous because a spinning propeller is under enormous stress, and a crack can grow quickly or cause a blade to fly off.
Context Anchor
Seen in hazard and risk discussions, preflight inspections, maintenance write-ups, and reports of propeller damage.
Derivation
From Latin 'fractura', meaning 'a breaking'. The same root gives us 'fracture' in medicine — a broken bone. Here it refers to the propeller breaking or cracking in the same sense.
Why Pilots Care
An undetected prop fracture can lead to blade separation, severe vibration, loss of thrust, or complete propeller failure in flight.
Grounding Statement
Even a small crack can grow when the propeller is spinning under engine power.
Intuition Check
Do not think of a prop fracture only as a propeller piece that has already snapped off. A crack is also a fracture, and in this term prop means propeller, not a support.
Example Sentence 1
During the preflight, the pilot ran a hand along each blade and found a small nick that, if left unaddressed, could lead to a prop fracture.
Example Sentence 2
Continued operation with a prop fracture risks rapid crack growth under flight loads.