Definition
A property of a material that causes it to break or shatter suddenly when stressed, rather than bending, stretching, or deforming first. A brittle material fails with little or no visible warning and shows almost no permanent change in shape before fracture.
Plain English
Brittleness means the material snaps instead of bending. It breaks cleanly and suddenly when pushed too far, instead of giving a little first.
Context Anchor
Seen in aircraft maintenance and inspection discussions about metal, plastic, rubber, composite parts, and other materials used on or around an aircraft.
Derivation
From the Old English brytel, meaning 'easily broken.' The same root sits behind 'brittle' in everyday speech. The aviation meaning matches the everyday one closely, but the focus is on how the material fails (sudden break with no warning) rather than just being fragile.
Why Pilots Care
Helps determine whether a structural component will fail suddenly without visible warning signs.
Analogy
Think of a dry twig versus a green branch. The dry twig snaps cleanly the moment you bend it. The green branch flexes a long way before it gives. Brittle materials behave like the dry twig.
Intuition Check
Brittleness does not simply mean weakness. A brittle material may be hard or strong, but when it is overloaded it tends to crack or snap instead of bending.
Example Sentence 1
Cast iron has high strength under compression but its brittleness makes it a poor choice for parts that take sudden impact loads.
Example Sentence 2
Inspectors check for brittleness in older composite parts before approving them for continued service.