Plain English Meaning
The NTSB is the government body that investigates aircraft accidents to figure out what went wrong and how to stop it from happening again. It does not make rules or punish anyone -- it studies what happened and recommends changes.
Full Definition
An independent U.S. federal agency responsible for investigating civil aviation accidents and significant incidents, determining their probable cause, and issuing safety recommendations to prevent recurrence. The NTSB also investigates accidents in other transportation modes (rail, highway, marine, pipeline) but is best known to pilots for its role in aviation accident investigation. It has no regulatory or enforcement authority -- it investigates and recommends; the FAA and other agencies decide whether to act on those recommendations.
Context Anchor
Pilots encounter this term in accident reporting rules, accident reports, safety recommendations, and discussions of aviation safety lessons.