question about B737 wind data entry

[sky-738]

Can any one tell me what is the difference between wind entry in Perf page(crz wind) and the wind entry in RTE page.
I know the wind entry in RTE page is more detail , is there any other difference?like in the performance calculation?

[Denti]

The preflight performance page entry is supposed to be the top of climb wind (first TOC if you have to step climb). Some use the average wind during the whole flight there, however that gives rather poor fuel predictions and differences especially on medium lengths sectors (4 to 5 hours) or more can be quite a lot.

Since it's only two button clicks i usually just fill in the RTE DATA sector winds.

[sky-738]

thx , for this point RTE wind seems like more accuracy.

[RAT 5]

Personally I find this input to give inaccurate calculations. But back to the question. After you input the W/V on Perf page it will 'soft' input this W/V for the whole flight on all sectors. (I can't see why this should not be a quite accurate for fuel prediction and ETA if the the route average W/V is inserted.) I don't see much point in inserting TOC W/V. It is highly unlikely to get a continuous climb to FMC CRZ FL. Later you can insert RTE DATA W/V. This should give an accurate ETA, but I find it's not so good. When in CRZ the FMC prediction for current WPT & next WPT is made using actual wind. There after ETA & Fuel at destination uses RTE DATA W/V. That's what I've always been told.