When selecting a destination alternate, what condition requires two alternates?

When selecting a destination alternate, what condition requires two alternates?

• A. Weather at departure
• B. Weather at destination; if there is no weather at the destination, two alternates will need to be chosen
• C. Destination weather irrelevant
• D. Always three alternates

Answer: (B)

When planning an IFR flight, you file an alternate airport based on the reliability of weather information for the destination. The situation that triggers needing two alternates is when there is no weather information available for the destination. In that case, you can’t assess whether the destination will have acceptable landing conditions, so you must designate two alternate airports to ensure you have viable options if one site can’t be used. This is why the correct idea centers on the lack of weather data for the destination. If weather at the destination is available and forecast to meet landing minimums, you’d typically need only one alternate (or as required by the specific rules you’re following). The other options don’t describe the actual rule: departure weather doesn’t dictate the number of alternates, irrelevant destination weather would be a different scenario, and there isn’t a universal requirement for always using three alternates.

When planning an IFR flight, you file an alternate airport based on the reliability of weather information for the destination. The situation that triggers needing two alternates is when there is no weather information available for the destination. In that case, you can’t assess whether the destination will have acceptable landing conditions, so you must designate two alternate airports to ensure you have viable options if one site can’t be used.

This is why the correct idea centers on the lack of weather data for the destination. If weather at the destination is available and forecast to meet landing minimums, you’d typically need only one alternate (or as required by the specific rules you’re following). The other options don’t describe the actual rule: departure weather doesn’t dictate the number of alternates, irrelevant destination weather would be a different scenario, and there isn’t a universal requirement for always using three alternates.