What is required at an alternate for weather conditions during approach?

The requirement for weather conditions at an alternate airport during an approach is that both the ceiling and visibility must meet the established minimums. This ensures that a pilot has the necessary conditions to safely execute an instrument approach and land if they need to divert to the alternate instead of their original destination due to unfavorable weather.

In practice, when an alternate airport is selected, federal aviation regulations stipulate that the visibility and ceiling conditions must not only meet either one of the minimums but must exceed both to provide a safe margin for operations. This dual requirement reduces the risk of encountering low visibility or a low ceiling that could jeopardize landing safety.

Other options may imply only meeting one of the conditions separately or specifying them incorrectly, but the central tenet is that a secure and safe approach demands adequate visibility along with an appropriate ceiling above threshold minimums.