3585/c55 Alternates

[flylike44]

someone please explain this concept. my head is spinning.

 

[avbug]

So's mine, reading your post. We're not mind readers. You want to expand on that a little?

What don't you understand?

 

[flyf15]

3585 is actually pretty simple. It applies to you if this is the case:

1) TAF for destination requires alternate
2) Main body of TAF is at or above minimums
3) Conditional statement during your timeframe is below minimums but not more than 1/2 of them

If those 3 conditions are met, 3585 can be used to still allow dispatch. It requires 2 alternates listed instead of 1.


There are, of course, a lot more details to it, but that is the simple short version of whats going on. I'm sure your airline's FOM describes it (and exactly how it can and will be used at your airline) and your standards department has people who can fill in any gaps from there...

 

[PURPLEHAZE21]

I used to teach it...take out a piece of paper and write the mins out for your choice of alternates. Now apply the rule 3585. If you don't do this, the dispatcher who filed you the alternate most likely gave you an illegal one, and now your responsible. Not everyone has 3585 in there ops specs...good luck

 

[climbhappy]

from my notes:

dest: taf period covering ETA, not less required vis in taf ; and with condtionals, not less than half the required visibility value.

1st alternate: not less than 1/2 the vis valuein the condtionals; not less than mins at ETA

2nd alt: if those apply, we use a 2nd: it must : TAF and metar will at or above derived mins for 2nd alt, no conditionals at all

remember derived mins? for a facility with one straight in , add 200/1/2 to the precision, 400/1 to the non prec

hope this helps, i'm learned to save all my notes from all my ground schools, it always helps.

 

[skydiverdriver2]

It's actually 200 and 1/2 that you add if it has two streight in approaches to different runways, or add 400 and 1 if it only has one. Sometimes the one navaid rule is better, DCA comes to mind. Also, different runways can be the opposite ends of one slab of pavement. The antennas and equipment for two ILS's at the ends of the same runway are counted as two, even if they are on the same frequency.

Remember that the ceiling requirement is only for the forcast, for planning. When actually flying the approach, you only need visability.

 

[great cornholio]

It's actually 200 and 1/2 that you add if it has two streight in approaches to different runways, or add 400 and 1 if it only has one. Sometimes the one navaid rule is better, DCA comes to mind. Also, different runways can be the opposite ends of one slab of pavement. The antennas and equipment for two ILS's at the ends of the same runway are counted as two, even if they are on the same frequency.

Remember that the ceiling requirement is only for the forcast, for planning. When actually flying the approach, you only need visability.

They can have the same freqs but must have different IDs. Also the runway must be suitable IE long enough, not closed, etc for an approach to count. Our POI says we have to take wind into account so if we have runway 9/27 with an ILS to both sides but the wind is 270 at 15 then we cant consider any app to 9 cause it has a tailwind component greater than our max tailwind allowance so runway 9 is "not suitable"