Alternate airport for destination: IFR or over-the-top: Domestic operations

This regulation requires dispatchers to list at least one alternate airport for each destination when dispatching flights under IFR or over-the-top. If weather at both the destination and first alternate is forecast to be marginal, a second alternate must be added.

However, no alternate is required if weather forecasts indicate that for one hour before through one hour after the estimated arrival time, the destination will have at least a 2,000-foot ceiling and 3-mile visibility.

Any required alternate airports must meet specific weather requirements found in §121.625 and must be listed in the dispatch release. This ensures flights have a viable backup plan if the destination becomes unavailable due to weather, but recognizes that alternates aren't necessary when destination weather is clearly adequate throughout the arrival window.

This applies specifically to Part 121 domestic operations—scheduled airlines and commercial operators flying within the United States.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*