Alternate Minima

Alternate minima are the specific weather criteria — primarily minimum cloud ceiling height and visibility — required at an aerodrome for it to be legally nominated as a destination alternate. If the forecast at the intended destination meets conditions requiring an alternate, the planned alternate aerodrome must meet these minima to be a valid nomination.

Key Points

• •Determines whether a nominated alternate aerodrome is suitable — the alternate itself must meet these minima to be a valid nomination.
• •Standard Australian VFR alternate minima require a <strong>1,500 ft ceiling and 8,000 m visibility</strong> for aeroplanes; rotorcraft in Class G airspace have a day VFR alternate minima of <strong>1,000 ft and 3,000 m</strong>.
• •Buffer periods of <strong>30 minutes</strong> apply to the start and end of forecast weather conditions when using a standard TAF; these also apply to INTER, TEMPO, and BECMG periods, except within the first 3 hours of a TAF3.

Related Terms