Every accident in the NTSB database carries a damage classification — usually Minor, Substantial, or Destroyed. These are not casual descriptions; the NTSB defines them by regulation, and the definitions are narrower and more specific than the plain-English words suggest.
Substantial damage
Under 49 CFR 830.2, substantial damage means damage or structural failure that adversely affects the aircraft's structural strength, performance, or flight characteristics, and that would normally require major repair or replacement of the affected component. It is a real, meaningful classification — but the regulation goes out of its way to exclude several categories of damage from counting as "substantial," including:
- Engine failure or damage limited to a single engine, if that is the only damage.
- Bent fairings or cowling, damaged landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips.
- Ground damage to a rotor or propeller blade.
- Minor punctured skin.
So an aircraft with an event on record is not automatically an aircraft with airframe damage — the regulation was written to keep routine, repairable mishaps out of the "substantial" bucket. Read the narrative, not just the classification, before drawing a conclusion.
Destroyed
Destroyed is exactly what it sounds like and is the least ambiguous of the three: the aircraft was damaged beyond economical repair, or was so extensively damaged that it could not reasonably be rebuilt. An airframe carrying a "Destroyed" event under one N-number that later turns up registered under a different tail number is precisely the situation a serial-number cross-check exists to catch — the classification survived even though the tail number did not.
Minor
Damage that does not rise to the level of "substantial" as defined above. An event can still appear in the NTSB database — because the event itself (not just the damage) met the reporting threshold, for instance an injury occurred — while the aircraft damage recorded is minor or none.
What the classification does not tell you
None of these three words describe the quality of any repair that followed. "Substantial" damage that was properly repaired, inspected, and documented can be a perfectly airworthy airplane; the classification only describes the damage at the time of the event, not what happened afterward. That is exactly why the record exists to prompt a question, not answer one — see the aircraft's actual repair documentation before you draw a conclusion either way.