What is the minimum sector obstacle clearance provided within 25 NM of a facility?

The minimum sector obstacle clearance provided within 25 nautical miles of a facility is established to ensure safety during instrument approaches and departures. The correct choice, which states a minimum clearance of 1,000 feet, reflects guidelines set forth in aviation regulations and standards.

This clearance is crucial to provide a buffer against potential obstacles, such as terrain or man-made structures, ensuring that aircraft can operate safely within this critical proximity to the facility. This minimum vertical separation helps to mitigate the risk of collisions and improve overall situational awareness for pilots navigating in the vicinity of airports and other navigational aids.

In contrast, lower clearance figures, such as 500 feet, do not provide sufficient margin for unforeseen circumstances or errors in altitude management, while higher clearances, like 1,500 feet or 2,000 feet, may be unnecessary and could complicate approach procedures without justifiable safety benefits. Therefore, the value of 1,000 feet strikes an essential balance between safety and operational efficiency.