Plain English Meaning

Short official notices that tell pilots about recent or short-term changes affecting flight, such as a closed runway, an out-of-service navigation aid, a temporary flight restriction, or unlit obstacles. They cover things that happen too quickly or last too briefly to make it onto printed charts.

Full Definition

Time-critical aeronautical information that is either temporary in nature or not known far enough in advance to be published on aeronautical charts or in other operational publications. NOTAMs convey information about the establishment, condition, or change in any aeronautical facility, service, procedure, or hazard, the timely knowledge of which is essential to personnel concerned with .