Which statement accurately describes VDP determination methods?

• A. Time Method uses MDA in AGL divided by 10 to estimate seconds before MAP; Distance Method uses (MDA in AGL x 3)/1,000 to estimate miles from runway
• B. Time Method uses MDA in AGL divided by 100; Distance Method uses MDA in AGL times 2
• C. Time Method uses MDA in MSL divided by 10; Distance Method uses MDA in AGL divided by 10
• D. Time Method uses MDA in AGL divided by 5; Distance Method uses MDA in AGL times 5 divided by 1,000

Answer: (A)

VDP determination uses two practical rules to translate the published MDA into a position on the final approach: a time-based method and a distance-based method. The time method says to take the MDA in feet AGL and divide by 10 to get seconds before the missed approach point. The distance method uses the MDA in feet AGL, multiply by 3, then divide by 1,000 to get miles from the runway to the VDP. For example, an MDA of 600 ft AGL yields about 60 seconds to the MAP using the time method and about 1.8 miles from the runway using the distance method. These formulas use MDA in AGL and simple constants to place the VDP relative to the runway and MAP; other formulations would mix units or use incorrect factors.