What type of NOTAM is regulatory in nature?

FDC NOTAMs, or Flight Data Center Notams, are regulatory in nature because they contain information that affects flight operations and must be adhered to by pilots. These NOTAMs typically pertain to changes in regulations, procedures, or aeronautical charts, and they have a direct impact on aviation safety and compliance.

For example, if there is a change in airspace boundaries, an FDC NOTAM will inform pilots of these changes, thus ensuring they are aware of new flight rules or navigation procedures that they must follow. This regulatory nature means that, unlike other types of NOTAMs, pilots are required to comply with the information contained within FDC NOTAMs in order to operate safely and legally.

On the other hand, local NOTAMs generally provide information relevant to specific airports or areas, while distant NOTAMs may cover regions or services outside the immediate flight area without necessarily requiring compliance. Special NOTAMs can relate to significant events or alerts but are not inherently regulatory, meaning they don't always require a mandatory response from pilots.