Definition
Damage to an aircraft structure that, if not repaired correctly, could affect the aircraft's airworthiness by reducing its strength, performance, flight characteristics, or operational safety. Major structural damage typically involves primary load-bearing components such as spars, longerons, ribs, bulkheads, fittings, or skin in stressed areas, and any repair must be carried out using FAA-approved data and signed off by appropriately rated personnel.
Plain English
Damage serious enough that the aircraft is no longer safe to fly until it has been properly repaired and inspected. The repair has to follow approved instructions and be signed off by someone qualified.
Context Anchor
You may see this term after a hard landing, bird strike, ground collision, hangar accident, or maintenance inspection.
Derivation
Structural comes from Latin words related to building or arranging something. Damage comes through Old French and means harm or injury. Major comes from Latin meaning greater. Together, the phrase points to harm to the built strength of the aircraft that is greater than a minor surface problem.
Why Pilots Care
The classification decides whether the aircraft stays grounded, what repair approval is needed, and whether a ferry permit or special inspection is required.
Intuition Check
Major does not always mean the damage looks dramatic. Structural does not mean every scratch or dent; it means the damaged area affects parts that carry loads or keep the aircraft strong.
Example Sentence 1
After the hard landing bent the main spar, the inspector classified it as major structural damage and the aircraft was grounded pending an approved repair.
Example Sentence 2
Because the tail strike caused only minor skin dents and no major structural damage, the airplane was released for the next flight after a visual inspection.