777 ALTN Page 2 FMC Queries

[craig_read 43]

I'm trying to understand the data that's entered into this page, see below:

 

http://www.theairlinepilots.com/forum/viewtopic.php?t=756&sid=7c16c0bc5b8c6e6e08df8215f39ae4b5

 

As with the 777 FMC here there is a page 2 for each alternate in the list.  The interested areas are WIND and ALT/OAT, but which level is it refering to?  Is it an expected level for the flying portion of the diversion, so for a field significant distance this could be say 20,000 feet or more, or is it conditions at say 3000 feet above the field.  I'm trying to understand and I've done an extensive search.  I assume it's used for fuel calculations for routing to the field. 

 

Is it an average wind and temperature component for a given altitude?

 

If someone could give me a view and perhaps some examples of how it would be completed that would be great!

 

Cheers

 

Craig Read

[scandinavian13 5,192]

 

 

Is it an expected level for the flying portion of the diversion, so for a field significant distance this could be say 20,000 feet or more, or is it conditions at say 3000 feet above the field.

 

You're no longer on your predicted path, so your estimates of being on the ground are no longer accurate. My understanding is that It's a gross estimate of the enroute wind to be used to predict the ETA and FUEL immediately below it.

 

 

 

Is it an average wind and temperature component for a given altitude?

 

Keep in mind that, with things like a diversion in the NAT HLA (prev. NAT MNPS) region, you're going to have to offset, descend and remain below the tracks during that diversion, so you're going to be off OPT and you may not have wind for that altitude specifically. The flight folder, as an example, contains wind levels at only (FLs) 050, 100, 180, 240, 300, 340, 390, 450, 630.

[craig_read 43]

Thanks for that Kyle,

 

I will try to put this into practice, do you think it's something that gets filled out during flight or more something that's done if the situation arises?

[downscc 1,327]

 

 

do you think it's something that gets filled out during flight or more something that's done if the situation arises?

 

Just guess but I think a diversion route is planned using RTE2, at least that is the way I do it.  Once the route is entered you can simply download the enroute and descent winds, keep it simple.