What happens to NDB-protected airspace as it approaches the adjacent NAVAID?

The correct answer indicates that the NDB-protected airspace diverges at angles of 5 degrees as it approaches the adjacent NAVAID. This divergence is crucial for ensuring that aircraft can maintain a safe navigation margin as they transition between the coverage areas of different NDBs (Non-Directional Beacons).

As pilots approach an NDB, the need for increasing separation from the areas served by nearby NDBs becomes more prominent due to potential interference and signal overlap. The 5-degree divergence allows for adequate buffer space, minimizing the risk of confusion or navigation errors, especially in areas where multiple NDB signals might be perceived by an aircraft’s navigation equipment.

In contrast, options suggesting 2 degrees or a constant distance do not adequately account for the need for increased separation and protection as the aircraft nears the boundary of different navigation service areas. Additionally, the choice indicating a narrowing to 2NM does not apply since the protection zone is designed to encompass a wider area to account for navigation discrepancies. This structured approach to airspace management enhances safety and reliability in navigating by NDBs.