What is the airspace that pilots are requested to voluntarily avoid?

The airspace that pilots are requested to voluntarily avoid is the national security area (NSA). This type of airspace is established for security purposes, and while flight through it is not prohibited, pilots are encouraged to steer clear of these areas to maintain safety and security. The designation serves as a warning to pilots about potential military operations or other sensitive activities in that airspace.

In a national security area, there is no legal restriction like there is in prohibited or restricted areas, where access is more controlled due to specific activities. Understanding the nature of NSAs helps pilots be aware of heightened security concerns and facilitates a collaborative understanding between air traffic control and aviation professionals regarding safety practices.

In contrast, prohibited areas are strictly off-limits to all aircraft, restricted areas may allow limited access with specific permissions, and warning areas typically indicate the presence of potential hazards to aircraft, especially when they're over international waters. Each of these categories serves different safety and operational functions in airspace management.