Plain English Meaning
Parts of the airplane that are designed to crumple in a crash so the people inside take less of the hit.
Full Definition
Airframe components — typically in the landing gear, fuselage belly, or seat mounts — that are engineered to deform progressively on impact, absorbing energy and reducing the forces transmitted to the occupants.
Context Anchor
Seen in emergency landing and crash-survivability discussions, especially when considering how impact forces are reduced.
Derivation
From 'crush' (to deform under pressure) plus 'structure' (the load-bearing parts of the airframe). The name signals the design intent: these parts are meant to be sacrificed in a crash so the cabin around the occupants stays more intact.
Why Pilots Care
It directly increases the chance of surviving a hard landing or crash by reducing peak on occupants and .