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FlySmiley · April 11th, 2008, 00:16

The reason you file an alternate in the first place is because there is a "chance" you will not get in to your destination right?

So why would you want your plan B to be setup for failure from the start? In the example of a NOTAMed glideslope it is pretty obvious you aren't going to shoot that ILS. For this reason if you cannot plan on being able to use the ILS, the minimums to file that airport as an alternate would need to increase. Likewise, if there is terrain or another factor that increases the normal approach minimums, chances are the minimums to use that airport as an alternate also increase (non-standard).

On the practical application end, the filed alternate simply satisfies a legal requirement that you will not only be able to land, but more importantly, have the fuel to do so. Remember, you are not required or even necessarily expected (generally speaking) to divert to your filed alternate if you are unable to land at your original destination.

If the winds are simply favoring one approach over another that is fine, however, if the winds would cause you to exceed a limitation by attempting the approach (i.e. tailwind landing limits, etc.) then IMO you would need to exclude that approaches availability when determining the alternate weather minimums.

April 11th, 2008, 00:16	#10
FlySmiley Junior Member Join Date: May 2005 Posts: 173	Re: Takeoff Alternates The reason you file an alternate in the first place is because there is a "chance" you will not get in to your destination right? So why would you want your plan B to be setup for failure from the start? In the example of a NOTAMed glideslope it is pretty obvious you aren't going to shoot that ILS. For this reason if you cannot plan on being able to use the ILS, the minimums to file that airport as an alternate would need to increase. Likewise, if there is terrain or another factor that increases the normal approach minimums, chances are the minimums to use that airport as an alternate also increase (non-standard). On the practical application end, the filed alternate simply satisfies a legal requirement that you will not only be able to land, but more importantly, have the fuel to do so. Remember, you are not required or even necessarily expected (generally speaking) to divert to your filed alternate if you are unable to land at your original destination. If the winds are simply favoring one approach over another that is fine, however, if the winds would cause you to exceed a limitation by attempting the approach (i.e. tailwind landing limits, etc.) then IMO you would need to exclude that approaches availability when determining the alternate weather minimums.