Which minimums are used for planning an alternate's weather?

Which minimums are used for planning an alternate's weather?

• A. Alt WX mins
• B. Enroute charts
• C. Performance data
• D. Notams

Answer: (A)

Alt WX mins are the weather thresholds used to determine whether an alternate airport is usable for planning. They come from the published instrument approach minima for that airport, or from the standard alternate minimums if none are published. The idea is to ensure you could land at the alternate safely if you needed to, even if the destination can’t be used. When you’re planning, you check the forecast weather at the alternate for your ETA and confirm it meets or exceeds those minimums. If the forecast falls short, that airport isn’t acceptable as an alternate, and you’d select another one. Enroute charts, performance data, and NOTAMs each serve other purposes (navigation, aircraft performance, and notices about hazards or closures, respectively) and do not set the weather criteria used to qualify an alternate.

Alt WX mins are the weather thresholds used to determine whether an alternate airport is usable for planning. They come from the published instrument approach minima for that airport, or from the standard alternate minimums if none are published. The idea is to ensure you could land at the alternate safely if you needed to, even if the destination can’t be used.

When you’re planning, you check the forecast weather at the alternate for your ETA and confirm it meets or exceeds those minimums. If the forecast falls short, that airport isn’t acceptable as an alternate, and you’d select another one.

Enroute charts, performance data, and NOTAMs each serve other purposes (navigation, aircraft performance, and notices about hazards or closures, respectively) and do not set the weather criteria used to qualify an alternate.