The standard alternate minimums are simple: 600-2 for precision approaches, and 800-2 for non-precision approaches. But non-standard alternate minimums can seem quite complicated.

What are the minimum weather conditions that must be forecast to list an airport as an alternate when the airport has no approved IAP? The ceiling and visibility at ETA must allow descent from MEA, approach, and landing, under basic VFR.

Per 14 CFR 91.175 f(2), standard minimums are: 1sm (or 5000 RVR) visibility for a/c with 1-2 engines and ½ sm (2400 RVR) for aircraft with more than two engines. This blanket regulation applies to all Part 121 operators unless additional factors waive or supersede this FAR.

An alternate must be filed, and the associated fuel carried, unless the exception applies. If the destination has an FAA-approved instrument approach and the weather between an hour before and after the ETA is at least a 2000-foot ceiling and three statute miles visibility, no alternate is required.

Standard alternate minimums for a precision approach are a 600-foot ceiling and 2 SM visibility. For a non-precision approach, the minimums are an 800-foot ceiling and 2 SM visibility. Standard alternate minimums apply unless higher alternate minimums are listed for an airport.

To view the non-standard IFR alternate minimums information, you will need to go to the Airports page > search for the airport > on the Procedures sub-tab, tap on Arrival > and then look for the Alternate minimums line. If there is an entry, tap on it and swipe through the pages until you find the airport in question.