Definition
The process of inspecting aircraft parts and structures to find cracks, corrosion, voids, or other defects, and then judging how serious those defects are and whether the part is safe to keep in service. It includes both visual checks and nondestructive testing methods such as dye penetrant, magnetic particle, eddy current, ultrasonic, and radiographic inspection.
Plain English
Looking carefully at a part to find any damage or hidden problems, then deciding how bad it is and whether the part can stay on the aircraft.
Context Anchor
Seen in aircraft maintenance, especially during inspections of metal parts, engine parts, propellers, landing gear, and other parts where hidden damage may matter.
Derivation
Flaw comes from Old Norse flaga, meaning a flake or chip — a small break in something otherwise solid. That image still fits: a flaw is a small imperfection in a part. Detection means finding it; evaluation means judging how serious it is. The pairing matters because finding a flaw is only half the job — the technician also has to decide what to do about it.
Why Pilots Care
Undetected flaws can grow into structural failures that directly affect flight safety.
Intuition Check
Do not read this as just “looking for flaws.” Detection finds the flaw; evaluation decides whether that flaw matters and what action is required.
Example Sentence 1
The technician used dye penetrant inspection for flaw detection on the landing gear strut, then referred to the manufacturer's manual for evaluation of the crack he found.
Example Sentence 2
Following flaw evaluation the inspector approved the wing skin for continued service.