If the MDA is 900 ft AGL, what is the Visual Descent Point distance from the runway threshold?

• A. 3 nautical miles
• B. 9 nautical miles
• C. 0.9 nautical miles
• D. 30 nautical miles

Answer: (A)

Visual Descent Point is where you can begin a normal descent from the MDA to the runway on a standard 3-degree glide path. With an MDA of 900 ft AGL, the vertical drop per nautical mile on a 3° path is about tan(3°) × 1 NM ≈ 0.0524 × 6076 ft ≈ 318 ft. So the horizontal distance required to lose 900 ft of altitude is 900 / 318 ≈ 2.8 NM, which is about 3 NM. Therefore the VDP distance from the threshold is roughly 3 nautical miles.