Definition
A section in the front of each Terminal Procedures Publication (TPP) volume that lists non-standard alternate airport weather minimums and identifies airports where filing as an alternate is not authorized (NA). When standard alternate minimums do not apply at a particular airport, that airport is listed here along with the specific ceiling and visibility required to file it as an alternate on an IFR flight plan.
Plain English
A reference section in the approach chart booklet that tells you which airports have unusual rules for being listed as your backup airport on an IFR flight plan, and what weather you need to use them.
Context Anchor
Seen during instrument preflight planning, especially when checking whether a planned alternate airport is allowed and what forecast weather is required.
Derivation
Alternate comes from a Latin word meaning “one after the other” or “by turns.” Minimum comes from Latin meaning “smallest.” Together, the idea is the smallest allowed weather conditions for the airport that would be used if the planned destination cannot be used.
Why Pilots Care
Ensures the chosen alternate airport will be usable if the primary destination becomes unavailable due to weather.
Grounding Statement
Before filing an instrument flight plan with a backup airport, the pilot checks this section to confirm the backup airport is allowed and has enough forecast weather.
Intuition Check
Do not read “alternate” as just any convenient backup airport. In this context, it means an airport that meets the FAA rules for use as the planned backup on an instrument flight plan. “Minimums” are not personal comfort limits; they are the published lowest weather conditions allowed for that use.
Example Sentence 1
Before filing IFR to a coastal airport, the pilot checked the Alternate Minimums Section and found their planned alternate required a 1,000-foot ceiling and 2 miles visibility instead of the standard 600 and 2.
Example Sentence 2
Weather at the destination was below the alternate minimums section values, so the pilot selected a different backup airport.