Definition
An imperfection or defect in a material or component that may compromise its strength, integrity, or function. Flaws include cracks, voids, inclusions, porosity, delaminations, or surface irregularities, and are the primary targets of nondestructive inspection methods used in aircraft maintenance.
Plain English
A hidden or visible defect in a part — like a crack, bubble, or weak spot — that could cause it to fail.
Context Anchor
Seen in aircraft inspection, maintenance records, preflight checks, and discussions of whether a part is airworthy.
Derivation
From Old Norse 'flaga,' meaning a flake or slab broken off a stone. The original sense of a small break or chip carried into English as any defect or imperfection in a material.
Why Pilots Care
Undetected flaws can grow under flight loads and cause structural failure, so they directly affect airworthiness decisions.
Intuition Check
Do not treat a flaw as just a cosmetic mark. In aviation, a flaw may affect whether a part is safe to use.
Example Sentence 1
The mechanic used dye penetrant inspection to check the landing gear fitting for any flaw before returning it to service.
Example Sentence 2
Any flaw larger than the allowable size on the inspection sheet requires the part to be repaired or replaced before flight.