Two Operational Navigation Facilities to different suitable runways require which adjustments?

• A. Add 400 ft to MDA and 1 Statute Mile to landing minimums
• B. Add 200 ft to MDA or DA to the higher of the 2 approaches and add 1/2 Statute Mile to higher landing visibility mins
• C. No change to MDA or DA
• D. Add 600 ft to MDA

Answer: (B)

When you have instrument approaches to two different suitable runways, you must apply more restrictive minimums to ensure a safe outcome if either facility or approach becomes limiting. The approach minima from the two procedures are compared, and you work from the higher values.

Specifically, take the higher MDA or DA between the two approaches and add 200 feet. Then take the higher landing visibility minimum between the two and add one-half mile. The resulting figures become the required landing minimums for the operation. This extra 200 feet and extra 0.5 statute mile provide a safety margin when relying on two different navigation facilities to two runways, helping account for potential variations in obstacle clearance and pilot workload.

For example, if one approach has an MDA of 600 feet and visibility of 2 miles, and the other has a DA of 800 feet and visibility of 1.8 miles, you’d use the higher MDA/DA (800 feet) plus 200 feet (to 1000 feet), and the higher visibility (2 miles) plus 0.5 mile (to 2.5 miles). The operation would carry minimums of 1000 feet and 2.5 miles visibility. This approach ensures consistency in minimums when two different runways and facilities are involved.