During night operations, the aircraft must be at least how many feet above the highest obstacle within 5 miles horizontally?

• A. One thousand feet above the surface
• B. One thousand feet above the highest obstacle within 5 miles
• C. Five hundred feet above the surface
• D. Two thousand feet above the highest obstacle within 5 miles

Answer: (B)

When flying at night, you must maintain a safety margin above terrain and obstacles in your vicinity. The rule requires you to be at least 1000 feet above the highest obstacle within five miles of your flight path. This gives you a reliable vertical buffer in low-visibility conditions and reduced visual cues after dark.

To apply it, determine the tallest obstacle within a five-mile radius of your route, then ensure your altitude is at least that obstacle’s height plus 1000 feet. For example, if the tallest obstacle in that area is 4,500 feet high, you must be at or above 5,500 feet. This focuses on obstacles, not just the surface, which is why being only 1000 feet above the ground (the surface) could still put you too close to tall obstacles. The 500-foot option is even less protection, and the 2000-foot buffer is more than required in this standard situation.