definition of en route alternate wanted
 

Hi all,
I m looking for the most exhaustive Jaa compliant definition (in terms of location/distance from what, ground facilities, weather) of
"en route alternate" for non Etops flights operated by two engined aircraft.
What should I check in my briefing charts(notam/meteo) at the planning stage to decide to commence a flight or to stay on ground?
Any help, please?
If, say, I have to do a 3 hours flight and in the briefing room I see that I only have cat 3 weather airports all the way down to the destination(destination escluded), am I allowed to commence that flight or not?

For 2-engined NON-etops operations, you should remain within one hour still air flying time of an adequate airfield. Adequate refers to runway length and availability - the fact that the airfield weather would require a CAT 3 approach does not prevent the legality of the flight although airmanship might bring it into consideration.

If i understand your question correctly then this is what i know...

The forecast weather at your destination must be at or above the airfields published landing minimas for the serviceble navaids at ETA(+/-) 1Hr. If the weather conditions are below this, you can still continue to another destination via your original destination and be recleared to your original destination over head or en route.

The designated alternates have to have the following forecast weather requirements for you to dispatch the Flt.

*If the Approach aid avail is CAT II/III :- Weather required CAT I.
*If the Approach aid avail is CAT I :- Weather required Non precision minima.

(and so on......)

Also as a note you can use the VIS/RVR conversions for planning purposes.
ie. at night you can assume RVR will be reported vis times 1.5-2!

Would give more info but have no time right now, sorry. hope this helps...:ok: