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Copper.

PFPX Fuel Plan v 747v3 Actual Fuel Used

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I wanted to create this thread to make some comparisons with other flight simmers.

 

PFPX had 13.9tonne (30644 lbs) remaining on yvr

747v3 ER FMC had 14tonne (30864 lbs) remaining at yvr during preflight BEFORE a wind update.

747v3 ER FMC had 23.5tonne (51808 lbs) remaining at yvr during preflight AFTER a wind update.

I arrived into Vancouver with 21.9tonne (46958 lbs) remaining (on the rwy TDZ)

 

The questions are:

What is your experience between pfpx and 747v3 fuel predicted remaining and 747v3 actual remaining?

 

My PFPX install doesn't get the AS16 wind feed as I have PFPX installed on a seperate machine. That may count for something, I don't know. The winds didn't seem that far off, though.

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My flights so far have been within a couple of tonnes, with wind updates.

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does your pfpx install use the wind data from whatever weather program you use?

 

How long are the sectors do you fly? More than 5hrs? Mine was from Sydney to Vancouver.

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My pfpx uses as16 for wind data, gonna give it a try this WE, i pnly go less than 4hrs flight. I think you can update the wind data in flight

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I let ASN use its own data and PFPX use its own data (all real-world) and they are pretty accurate. (with just enough variation to simulate reality)

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Yeah cool. I do the same.

 

Wonder why PFPX has such a drastic difference for me. The PFPX winds correlate well enough with what got uplinked. Hmmm

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Which profile are you using in PFPX? Any fuel/drag bias figures entered?

 

Not sure if you were using it with the previous version - but that used to burn about 8-10% too much fuel (RR). I assume/hope PMDG have got a bit closer to the book figures with this one.

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Hey Simon, good to have the likes of you on the subject.

 

ER Pax. Thank you Mykyta!

http://forum.aerosoft.com/index.php?/files/file/3514-pfpx-boeing-747-400-performance-profiles-pack/

 

No bias set as yet, but if I need to alter the numbers, I will. I'll just collect data for now.

 

No I didn't use the QotS I for long haul and so I didn't have much need to flight plan. I only just got into long hauling. It's a different sort of flying, not sure if I like it... but I'll go through the motions until I decide.

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Which profile are you using in PFPX? Any fuel/drag bias figures entered?

 

Not sure if you were using it with the previous version - but that used to burn about 8-10% too much fuel (RR). I assume/hope PMDG have got a bit closer to the book figures with this one.

that has been since fs9 ...i do not know for the actual version.

 

but in the same time c-gagm was +9% on fuel burn so nothing unusual ....

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So far very close to what PFPX predict. I still use PFPX 1.19,  the later versions do have so many problems, I've tested, that I stayed on 1.19 and it works perfect the way I use it.

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Using the aircraft pack from the Ukraine gentleman, my UAL PW4056 bias was set to 1.8% based on a 5 min measurement during later period in a long trip.  I got varying results with the -400ER so I've not made an adjustment yet.

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Thanks Dan. This is what I get when I crunch some numbers. I don't know how good the adjustment is... Like you, for the ER I'll have do more data mining before I change things.

 

REQUIRED PFPX PARAMETERS
gross wt/alt/ci/sat/isadev/ff.hr/tas/gs

 

///WEIGHTS KG AND TEMPS C\\\

 

DURING FIRST FLT HR
372,200kgs/FL310/CI50/-33C/P12C/11,200kgs/504.5kts/511kts

DURING MID FLT HR
307,900kgs/FL350/CI50/-42C/P11C/9,400kgs/495.5kts/507.5kts

DURING LAST FLT HR
261,500kgs/FL390/CI50/-52C/P06C/7,800kgs/488.5kts/546kts

AVERAGED
313,867kgs/FL350/CI50/-43C/P10C/9,467kgs/497kts/522kts

 

PFPX BIAS RESULTS
Calc Fuel Flow/hr= 10,480 kgs
Calc TAS= 495 kts
Calc Mach= 0.837M
Fuel Bias= -9.7%
Drag= -0.4%

 

and for the wayward amongst us metric folk, the numbers converted ;P

 

///WEIGHTS LB AND TEMPS F\\\

 

DURING FIRST FLT HR
820,560lbs/FL310/CI50/-28F/P54F/24,691lbs/504.5kts/511kts

DURING MID FLT HR
678,803lbs/FL350/CI50/-44F/P52F/20,723lbs/495.5kts/507.5kts

DURING LAST FLT HR
576,508lbs/FL390/CI50/-61F/P43F/17,196lbs/488.5kts/546kts

AVERAGED
691,958lbs/FL350/CI50/-46F/P50F/20,871lbs/497kts/522kts

 

PFPX BIAS RESULTS
Calc Fuel Flow/hr= 23,105 lbs
Calc TAS= 495 kts
Calc Mach= 0.837M
Fuel Bias= -9.7%
Drag= -0.4%

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I did a EDDT->PHNL flight last week and recorded fuel consumption and times on my printed pfpx flight plan. I use historical FSGRW and pfpx uses these data too. The flight time was on touch (flew 8h and it was off 1 minute from plan) until about 8h. Then I got some headwind and got behind schedule. As I had 3 tons of fuel more than planned I increased the polar flight from .840 to .880 to catch up the time. After 14h55 flight ended at phnl with only 3 minutes late and 1ton of fuel more than planned.

Was a 400 GE flight. So the pmdg has some lower fuel consumption than planned in pfpx.

I use the pmdg 400 GE pfpx profile template.

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Hallo Stefan, bist du aus Deutschland? (That's all the German I know)

 

14h55m! Now that's some serious long haul! My flight time for my next planned flight is 14h42m on a yssy to kdfw flight. This doesn't include sid/star flight time though, so potentially a little longer than that.

 

On your flight to phnl, were you payload restricted? What 747 did you use? -400GE Pax?

 

I might try that flight in a LH -400GE Pax if it can make it. Yes, judging by my above figures the PMDG 747ER is more fuel efficient.

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Did the yssy kdfw flight. 14h52m flight time. 15h11m block time. Never flown to Dallas before... The airport is huge! Got to be the biggest airport in the world?

 

With the bias set per my previous post.

 

Planned flight fuel - 145,400 kgs (14h42m)

Actual flight fuel - 149,300 kgs (14h52m)

Discrepancy - minus 3,900 kgs (23m - based on planned avg crz ff.ph for this flt 9,885 kgs)

 

No significant dev from planned route, except out of Sydney. Stayed on track a little longer to avoid the city. More tweaking to do.

 

Averaged measurements for syd/dfw using same methods in previous post:

319,900kgs/FL350/CI50/-47C/+7C/10,160kgs/490kts/512kts

 

With the previous bias still applied, PFPX gives these results:

Calc ff.ph - 10,598 kgs

Calc tas - 492 kts

Calc mach - 0.840M

Fuel bias - -4.1%

Drag - 0.4%

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Ok everyone, final post for this hopefully.

 

With the corrections previously posted respectively and individually inserted into PFPX FOR THE ER PAX ONLY, I've managed to get the arrival fuel discrepancy down to an acceptable level. I get to within 1tonne give or take 500kg which is tolerable.

 

My last two sectors

syd-hkg = +1200kg diff between planned and actual arrival fuel.

dfw-syd = +1100kg diff between planned and actual arrival fuel.

 

The dfw-syd took a whopping 16h27m flight time to cover a dist of 7547nm (not incl holding pattern distance), 16h47m gate to gate!! (20 mins spent in holding pattern at FL200).

 

How realistic!!!!! Thank you PMDG!

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Excellent work!  Thanks for keeping us in the loop with your findings.

 

Cheers,

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Thanks for your findings Brian. Dan, have you found a good bias value for the UAL PW 747s yet? On my flight from YSSY to KSFO yesterday, PFPX was estimating an arrival with 29000lbs left whereas after updating windsx the FMC was estimating over 40,000lbs and kept increasing slightly, before my sim crashed. The winds were fairly close to what PFPX was predicting as well. Just wondering if you or anyone else, have found the magic number yet?

 

Regards,

Rob

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Dan, have you found a good bias value for the UAL PW 747s yet?

 

Been mostly flying GEs lately but now have a UAL B744 PW enroute EDDF KSFO and my PFPX bias is 1.3% and the destination fuel is remaining at plan 28 klbs.

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I did 2 flights so far

 

TLV-BLR-TLV both on the 400F PW, around 15.5H total time in the air.

Both flights used CI of 55 and AS16 and PFPX.

 

Both times landed at around 300-700 KG more then planed (including CONT' fuel).

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Hi chaps,

For the 747-400 RR PAX and the RB211-524GH2 profile that comes with PFPX

After doing 12 bias calculations with PFPX at various weights on a number of flights, I have the following corrections to provide arriving at destination within +/ 500kg fuel remaining from planned and +/ 5 minutes of estimated time.  This is with Cost Index 100 - I haven't tried other CIs as yet.

Fuel Bias: -5.2%
Drag Factor: 1.0%

Cheers,

Rudy

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