What Is NOTAM? Definition & Meaning in Aviation
A NOTAM is a notice to pilots about a temporary change or hazard, such as a closed runway or restricted airspace. The name is usually expanded as “Notice to Air Missions” (older: Notice to Airmen).
In plain language
NOTAMs are issued by aviation authorities. They can close an airport for hours, restrict airspace, or warn that a navigation aid is out of service.
Example
A NOTAM could announce that one runway at an airport is closed for maintenance, so flights use the other runway.
Why it matters
NOTAMs are how closures and restrictions reach crews. When an airspace or runway notice affects a route, you may see aircraft take different paths on the live map and flights may take longer.