Working out average DES winds

[Driver170 42]

I'm hoping someone can steer me in the right direction on how to work out average DES winds?

 

And also why on TAKEOFF PAGE 1 you have GW and TOW and the TOW doesn't decrease as the fuel is getting burnt during taxi, but the GW does reduce? can someone explain this?

[scandinavian13 5,192]

 

 

I'm hoping someone can steer me in the right direction on how to work out average DES winds?

 

 

 

 

And also why on TAKEOFF PAGE 1 you have GW and TOW and the TOW doesn't decrease as the fuel is getting burnt during taxi, but the GW does reduce? can someone explain this?

 

Your GW is your ACTUAL gross weight, which will change as fuel burns off.

 

Your TOW is your PLANNED take off weight, which should not change as fuel burns off. You shouldn't be burning so much fuel that this value changes significantly. If you plan to, ensure that your TOW entry accounts for that change.

[Driver170 42]

cheers!

 

The TOW was 60.2 t and the GW was 60t when i lined up on the rwy?

Been looking at the CRZ wind entry in the PERF INIT page and found you enter the TOC wind and enter the wind in the legs page!

[scandinavian13 5,192]

 

 

The TOW was 60.2 t and the GW was 60t when i lined up on the rwy?

 

This is because the TOW auto-populates when you finish your PERF INIT info, I believe. Of course, you burn fuel in the taxi, so your GW decreases.

 

The FMC doesn't know what your taxi time, or distance will be, so it cannot assume a lower value than the auto value that it's given. Either adjust it to the current value when you get to the runway, or ignore the difference (provided it's negligible, which 200kg would be). Another option would be to use the value assumed in TOPCAT (it will give you an assumed TOW using your planned GW minus the assumed taxi fuel).

[Driver170 42]

So how do i actually change this TOW?

Kyle in the 737 NGX fs options i set my ZWF in the right to 55.3 t and my GW is then 60.1 do i can match my PFPX weights!

 

So how come in the PERF INIT page it shows GW 60.2 ?

[scandinavian13 5,192]

So how do i actually change this TOW?

Kyle in the 737 NGX fs options i set my ZWF in the right to 55.3 t and my GW is then 60.1 do i can match my PFPX weights!

 

So how come in the PERF INIT page it shows GW 60.2 ?

Honestly, you're hyperfocusing if you're worried about 100kg. You easily make up for that in the fact that passenger weights are averaged anyway, so your weights are already "wrong" even if you calculated it all "perfectly."

 

To answer your question, I believe you can adjust the TOW on the TAKEOFF REF page at the bottom right(-ish - going off of memory here).

 

The difference in weights between the FS ACTIONS page and the actual FMC side is due to rounding errors and the errors inherent in the actual gauges (simulated realistically).

[Spin737 102]

TOW is the RELEASE weight - what the company says you can takeoff at. The GW is the ZFW+fuel or your actual.

 

As far as regs go, your TOW should be equal to or less than the Release GW. You need to make sure you also have your REQ fuel.

[Driver170 42]

Driver170, on 06 May 2015 - 8:08 PM, said:

So how do i actually change this TOW?

Kyle in the 737 NGX fs options i set my ZWF in the right to 55.3 t and my GW is then 60.1 do i can match my PFPX weights!

 

So how come in the PERF INIT page it shows GW 60.2 ?

 

Honestly, you're hyperfocusing if you're worried about 100kg. You easily make up for that in the fact that passenger weights are averaged anyway, so your weights are already "wrong" even if you calculated it all "perfectly."

 

To answer your question, I believe you can adjust the TOW on the TAKEOFF REF page at the bottom right(-ish - going off of memory here).

 

The difference in weights between the FS ACTIONS page and the actual FMC side is due to rounding errors and the errors inherent in the actual gauges (simulated realistically).

 

I found a way to get it all matching by setting the weights in the PMDG first (pax and cargo etc) and then populate it in PFPX

 

I tried to change my TOW to 60.1 from 60.2 but it wouldn't change in the takeoff page 1

[Driver170 42]

TOW is the RELEASE weight - what the company says you can takeoff at. The GW is the ZFW+fuel or your actual.

 

As far as regs go, your TOW should be equal to or less than the Release GW. You need to make sure you also have your REQ fuel.

 

Thats the thing matt in the takeoff page 1 my TOW is fixed and stays at 60.2 but my GW reduces by 200kg at around my line up point which is my taxi fuel that has been burnt. But i can't seem to change this TOW fix

[Driver170 42]

Kyle can i just enter the ZFW in the PERF INIT PAGE like in the RW because this seems to work and match?

[pcubine 143]

Vernon

 

I get the ZFW in either way. Enter it thru FS ACTIONS>PAYLOAD or just key the ZFW as reported by PFPX on the INIT page. It makes no difference.

[Driver170 42]

It does make a difference with what way you enter it.

 

If you enter payload through FS OPTIONS your ZFW will be diff to PFPX ZFW

 

If you enter it through PERF INIT its spot on and matches PFPX

[Spin737 102]

TOW  GW is the RELEASE weight - what the company says you can takeoff at. The GW TOW is the ZFW+fuel or your actual.

 

As far as regs go, your TOW GW should be equal to or less than the Release GW TOW. You need to make sure you also have your REQ fuel.

 

Sorry, I reversed them.

Thats the thing matt in the takeoff page 1 my TOW is fixed and stays at 60.2 but my GW reduces by 200kg at around my line up point which is my taxi fuel that has been burnt. But i can't seem to change this TOW fix

 

Yeah, I screwed that up. It's the other way around. GW is the one that's changing with fuel. TOW is (at least at my company) the "release weight."

[Driver170 42]

Wouldn't you just say MIN TOW then matt instead of GW

Yeah, I screwed that up. It's the other way around. GW is the one that's changing with fuel. TOW is (at least at my company) the "release weight."

 

So basically TOW is the ramp weight by the sound of it?

[Spin737 102]

Wouldn't you just say MIN TOW then matt instead of GW

 

So basically TOW is the ramp weight by the sound of it?

RAMP would be TOW+TAXI.

 

Or RAMP-TAXI=TOW.

 

When you line up, make sure you have REQ fuel.