Which type of Notam is specifically related to navigational aids and en route information?

The type of NOTAM that is specifically related to navigational aids and en route information is the FDC NOTAM. FDC NOTAMs contain information that is regulatory in nature, such as changes to instrument approach procedures, airspace changes, and significant navigational information. These NOTAMs are critical for flight planning and ensure pilots have access to the most up-to-date navigational data necessary for safe flight operations.

In contrast, other types of NOTAMs serve different purposes. D NOTAMs generally provide information about the status of airports and related facilities but are not specifically focused on navigational aids or en route information. G NOTAMs pertain to general aviation activities and may cover temporary flight restrictions but do not specifically address navigational aids. S NOTAMs are associated with special use airspace or significant temporary changes in airspace usage that also do not focus primarily on navigational aids.

Therefore, FDC NOTAMs are the correct choice when considering information specifically related to navigational aids and en route conditions.