What must be added to the higher Decision Altitude (DA/H) or Minimum Descent Altitude (MDA) when using the second Nav Aid rule?

When utilizing the second Nav Aid rule, the altitude that must be added to the higher Decision Altitude (DA/H) or Minimum Descent Altitude (MDA) is 200 feet. This rule is applied to ensure an appropriate safety margin above the established altitudes.

Adding 200 feet provides an additional buffer to accommodate potential variations in navigation system performance, particularly when relying on two different navigation aids for approach. The guidance reflects the need for cautious operational practices in instrument approach procedures, where terrain and obstacle clearance is critical to safe flight operations.

Overall, the adjustment to the DA/H or MDA is part of a broader commitment to safety in aviation, ensuring that pilots maintain a necessary altitude above the terrain until visual reference is established or a safe decision is made to divert or go around if conditions do not permit a safe landing.