Definition
A defect in a bonded structure in which two layers or components that were originally joined by adhesive have separated, either partially or completely, from each other.
Plain English
Two parts that were glued together have come apart.
Context Anchor
Seen in aircraft maintenance, especially during inspections of bonded joints, composite parts, panels, and repairs.
Derivation
From 'de-' (Latin, meaning 'reverse' or 'undo') plus 'bonding' (the act of joining). Literally 'un-joining' — the reversal of a bond that was supposed to hold.
Why Pilots Care
Undetected debonding reduces structural strength and can lead to in-flight failure of critical components.
Analogy
It is like tape or glue starting to peel away from a surface. The pieces may still be touching, but the holding connection is failing.
Intuition Check
Debonding does not mean a surface is just scratched or dirty. It means the connection between joined surfaces has failed or is starting to fail.
Example Sentence 1
The technician tapped along the composite panel and identified an area of debonding by the change in sound.
Example Sentence 2
Regular tap testing helps detect debonding in the honeycomb panels before it spreads.