What is the maximum obstruction angle of the approach for night operations?

• A. 6 degrees
• B. 3 degrees
• C. 5 degrees
• D. 4 degrees

Answer: (D)

During night operations, the approach must remain as shallow as possible to keep good obstacle clearance and compensate for reduced visibility and depth perception. The obstruction angle of the approach is the maximum allowable downward angle as you descend toward the landing zone while staying clear of obstacles on the approach path.

Four degrees is the standard maximum because it provides enough descent toward the LZ without compromising safety near obstacles, especially when visibility is limited. Angles greater than this increase the risk of striking obstacles on the approach or near the landing zone, which is why higher options are not acceptable. A smaller angle, like three degrees, would be safer but would not represent the maximum permitted, which is what the question asks.