Weather below the alternate minima requires you to plan an alternate (or carry holding fuel if the weather is fluctuating ie INTER or TEMPO). The special alternate minima can be used in certain circumstances if the aircraft is appropriately equipped. An aerodrome can not be planned as an alternate if it itself requires an alternate. Full details in the Jeppesen manual or AIP.
Last edited by AerocatS2A; 28th Nov 2012 at 22:08.