What does a NOTAM D signify?

A NOTAM D, which stands for "Notice to Airmen, Type D," signifies a widespread dissemination requirement related to information about navigational facilities, airspace, or flight operations that may affect pilots. Specifically, it generally pertains to information that is important for flight safety but does not require immediate action, such as the status of navigational aids or changes to airport operations.

This type of NOTAM provides crucial information to pilots regarding navigational aids that might be out of service or may have undergone a change, ensuring that they are informed about any factors that could impact their navigation and safety during flight. The information in a NOTAM D is intended for general distribution, making it accessible for all relevant aviation personnel.

The other options pertain to different types of notifications or restrictions in aviation. For instance, an urgent message aimed at all pilots would typically be classified under a different NOTAM type unless it specifically indicates its urgency. A temporary restriction on flight operations might fall under NOTAM types that indicate airspace closures or specific flight prohibitions, which are more specific than the information provided by NOTAM D. Similarly, while disallowing airspace use could be conveyed through a NOTAM, it does not accurately define the broader nature of the NOTAM