Takeoff alternate aerodrome is required when return for landing cannot be
made after takeoff if the weather at takeoff is below the landing minima
as in ICAO, Annex 6.
According to your example, there's airworthiness requirement that the aircraft
must have fuel jettison system if the aircraft cannot reach approach/landing
climb requirement at weight after takeoff for 15 minutes.
Last edited by galahad; 14th Sep 2009 at 18:10.