Definition
A maintenance technique used to halt the progression of a crack in a metal structure by drilling a small, round hole at the very end (tip) of the crack. The hole removes the sharp point where stress concentrates, slowing or preventing further crack growth until a permanent repair can be made.
Plain English
Drilling a tiny hole at the end of a crack to stop it from spreading any further.
Context Anchor
Seen in aircraft maintenance, especially during inspection or repair of cracked sheet metal, panels, or fairings.
Derivation
The name describes the action: a hole is drilled to stop the crack. The technique works because a sharp crack tip concentrates stress; replacing that sharp tip with a round hole spreads the stress out over a wider area.
Why Pilots Care
Maintains structural integrity and prevents a minor crack from growing into a critical failure that could affect airworthiness.
Analogy
A crack tends to keep running from its sharp tip. A round hole removes that sharp tip, like rounding off the end of a tear so it is less likely to continue tearing.
Intuition Check
Stop drilling does not mean stopping the act of drilling. Here, it means drilling a small hole to help stop a crack from spreading.
Example Sentence 1
The mechanic stop-drilled the crack in the inspection panel to prevent it from growing before the part could be replaced.
Example Sentence 2
Stop drilling provided a temporary fix until the damaged panel could be replaced.