Dan,

Well done to Steven and you in cornering the problem to using LBS.

 

I can now report my last flight's fuel usage in some detail:

 

I was fying a B77W from WSSS to EGLL, payload 62,209 kgs, fuel 112,121 kgs, zfw 230,038, and therefore a ramp weight of 342,159 kgs. I took off 20R, with an initial FL300, N1 176, Nr 186 and N2 192 with QNH 1009, at 0613z. Flight planned headwinds were HD018kts. The flight was conducted with re-dispatch at waypoint CH (Cherniakhiv, UKBV).

 

My fuel and timings over significant waypoints are show as comma-separated items with nms to run, FIR, time over (planned over - actual over/mins), fuel over (planned over - actual over/tonnes), and estimated fuel at EGLL/tonnes(earlier items not recorded):

 

5829,WMFC,0,-0.7,-

5749, WMFC,0,-0.5,-

5607, WMFC,0,-0.3,-

5535,WMFC,0,-0.2,-

5399,VTBB,+1,0,-

4839,VYYF,0,+0.9,-

4788,VECF,0,+1.0,-

4519,VECF,-1,+1.4,-

4405,VECF,-1,+1.6,-

3980,VIDF,-1,+0.9,-

3571,VIDF,+1,+2.8,-

3290,OPLR,+1,+2.9,-

3245,OPLR,+1,+3.2,-

3197,OAKX,+1,+3.2,11.8

2874,UTAV,+2,+3.5,12.0

2597,UTAA,+3,+2.9,12.2

2242,UATT,+2,+4.5,12.4

2105,UATT,+3,+4.5,12.5

1893,URRV,+2,+5.2,12.6

1629,URRV,+1,+5.6,12.8

1584,URRV,+1,+5.7,12.9

1237,UKBV,+1,+6.0,13.3

759,EPWW,+3,+6.5,13.0

649,EPWW,+4,+6.6,13.0

569,EPWW,+4,+6.6,13.1

430,EDVV,+4,+6.7,13.2

337,EDVV,+4,+6.8,13.2

 

From this, I can deduce that:

1. time over was later only because of headwinds encountered, and was more than compensated by tail winds later in the flight
2. fuel over gradually increased until the latest quoted showed FREM as 13.2 tonnes against a planned FREM of 6.8 tonnes.
3. the PFPX plan gives, if anything, more fuel than is necessary, but only by an acceptable margin given that the actual headwinds may worsen.

 

I hope that this helps in showing that I have great faith, so far, in PFPX giving me acceptable flight plans.

 

Tired after a 13.5 hr flight,

Cheers, Richard

 

 

the PFPX plan gives, if anything, more fuel than is necessary

 

Richard, the 6.8x1000kgs 'over fueled' compared to 62.2x1000kgs released fuel load is about 10%. I consider that an acceptable error especially because it is on the safe side (better than 10% under). So far with PFPX I have flown VHHHKDFW 14.5 hrs and KDFWPHNL 7.2 hrs and in both cases the surplus error was less than 3%. I notice that when I play with the PFPX aircraft evaluation, providing actual fuel flow and KIAS, the correction to fuel bias and drag seems greater than I want to accept based on my 'gut.' I am sticking to 100.0% values, and starting the return from PHNL to KDFW (AAL8).

Hi Dan,

 

I shall stick to 100% values as well. Notice that on long hauls I am also using auto re-dispatch to save fuel..

 

Cheers, Richard

Hi Dan,

 

I shall stick to 100% values as well. Notice that on long hauls I am also using auto re-dispatch to save fuel..

 

Cheers, Richard

My PHNL-KDFW flight planned with PFPX evaluation corrections; release fuel 133.8 (all weights klbs) for 7 hr flight at near MZFW, fuel remaining at KDFW planned 19.2 actual was 13.3 and that was after setting a lower mach cruise because I got into my 'worry zone' as I got dry feet on West Coast. Those correction factors are already back to 100%!! 

 

My next task is to become familiar to re-dispatch.  Thanks for the feedback.

Hi Dan,

 

Your KDFW flight looks good. Your FREM was around 4.5% in surplus.

 

You will find re-dispatch a little complex to start with, but it gives you an additional reason to watch your fuel levels as you approach the re-dispatch fix. I have found so far that I am again significantly in credit at this point.

 

You will find the manual (written by yours truly, but incomplete when I parted company with Chris Grill) as a part of PFPX deliverables. Good luck!

 

Kind regards, Richard

 

 

(written by yours truly, but incomplete when I parted company with Chris Grill)

 

Right, I saw your name on the credits for the documentation... 'hey, I know that guy!'  I am going to need a little more help with redispatch, tried it for the KLAX-EGLL AAL136 flight and found that the fuel release increased with a redispatch point at 6130N with redispatch alternate at BIKF Keflavik. I shrugged my shoulders and released the flight without redispatch figuring I'd have to do some research. I'm on that flight now enroute to 5920N and fuel/times looking right on plan.

Hi Dan,

How did the flight go?

Cheers, Richard

Hi Dan,

How did the flight go?

Cheers, Richard

Amazing. My first time over NAtl where I got to overfly Greenland, pretty cool. Fuel burn and time right on the money:  Fuel released 208.5 klbs planned fuel remaining 26.2 actual fuel remaining 24.2; planned flight time 9+53 actual 10+00.  Only glitch was navigraphs ILS09L BOVVA transition between BOVVA4A STAR and the IAP, they really messed up the entry to downwind and base legs and next time I go into EGLL I'll edit the sidstar file first.  I used to always use the procedures built by Steve Bell but I haven't seen him around the hobby for awhile. Next trip might be the return to KLAX AAL135... I'm finding a nice list of actual B77W AAL flights to play with.

Did you edit the template?

Hi Dan,

 

At EGLL, the normal procedure is to use the STAR to get you to either BNN (approach from north) or OCK (approach from south) as the two entry points. Because in real life EGLL is extremely busy at all times, many flights will be stacked at these entry points, or other marked waypoints prior. Approach controller will then vector you to the IAF.

 

In FSX/P3D without ATC, you have either to fly your own chosen headings and altitudes to gain the IAF, or consider using one of the available transition routes. I usually step down, reduce speed and fly the downwind heading quite easily, being prepared to avoid other aircraft landing by extending/shortening my downwind leg by agreement with the other pilot(s).

 

HTH,

Regards, Richard

Did you edit the template?

Yes, weights are adjusted slightly to match PMDG implementation and limitations in FCOMv1 for 300ER:  (all in 1000 lbs) EMPTY 369, MAX FUEL 320.825, MZFW 529.0, MRW 777.0, MTOW 775.0, MLDW 554.0; no other adjustments. All correction factors are default (e.g., 100%).

Thank you! Do you know if there is a downloadable template available like there was for the 77L?

What about cargo capacity?

I see that PFPX is taking more fuel than before. My problem is, that always land with too much fuel left

 

 

Do you know if there is a downloadable template available like there was for the 77L?

Here you go

 

http://forum.aerosoft.com/index.php?/files/file/2819-pfpx-boeing-777-performance-profiles-pack-part-one/

 

 

What about cargo capacity?

 

I started with the PMDG max cargo value from the FMS at 85,605 lbs but changed it to blank, which PFPX treats as a no-constraint. The MZFW is the hard constraint.