Which weather scenario requires filing a Second Alternate?

• A. Marginal Weather at Destination AND 1st Alternate with 1000/3 at Destination and 600/2 at 1st Alternate
• B. Only Marginal Weather at Destination
• C. Perfect weather at both airports
• D. Low fuel warnings

Answer: (A)

When planning an IFR flight, you must have alternates you can actually land at if the destination can’t be used. A second alternate is required when both the destination and the first alternate are forecast to be below the minimums that would allow a safe landing. In this scenario, the destination is showing marginal weather (ceiling around 1000 ft and 3 miles visibility), and the first alternate is even worse (600 ft ceiling and 2 miles visibility). If neither airport meets the needed weather minimums, there’s no reliable option available if the destination goes unusable, so you must file a second alternate. The other scenarios either provide at least one usable landing option or involve fuel considerations rather than weather sufficiency for alternates.