Definition
The breaking, bending, cracking, or permanent deformation of an aircraft component beyond its design limits, such that the part can no longer safely perform its intended function. In the context of landings, it typically refers to damage to the landing gear, tires, wheels, or supporting airframe structure caused by side loads imposed during a drifting or crabbed touchdown.
Plain English
A part of the airplane has been bent, broken, or damaged badly enough that it can no longer do its job safely. On landing, this usually means the gear, wheels, or the structure they attach to.
Context Anchor
In this chapter, the term appears in discussions of landing while the airplane is drifting sideways or still pointed partly across the runway.
Derivation
From Latin 'structura' (a building, arrangement of parts) and 'failure' (to fall short, give way). Together: the load-bearing arrangement of parts gives way. Helpful because it points to the issue being about the airframe itself, not a system or engine problem.
Why Pilots Care
A structural failure can destroy control of the airplane and turn a minor landing mistake into a serious accident.
Intuition Check
Do not read failure as only meaning the airplane completely comes apart. In this context, structural failure can be a bent, cracked, or loosened part that can no longer safely carry landing or flight forces.
Example Sentence 1
Touching down in a crab places side loads on the landing gear that can lead to structural failure.
Example Sentence 2
The pilot corrected the crab angle before touchdown to avoid placing side loads that might lead to structural failure.