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riccardo74

MD11/F correct fuel calculation and FMC initialization?

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Hi guys can someone resolve a doubt I have reguarding correct FMC WEIGHT INIT PAGE 2/3 initialization?

 

I planned with PFPX this route EDDF-VABB with a payload of 7778 kg (random from PFPX) and get this result:

 


GEC1652 EDDF-VABB (11 Mar 2015) #1

 

Fuel Planning (kg)       EU-OPS             Fuel      Time

 

TRIP                                                   41,461       07:42

CONT 5%                                            2,073       00:28

ALTN                             VAAU           3,198       00:24

FINAL RESV                                      2,156       00:30

MIN T/O                                            48,888       09:04

EXTRA                                                3,000       00:40

TAXI                                                       450       00:10

RELEASE                      EDDF         52,338       09:54

REMAINING                 VABB        10,202      01:57

 

Load Planning (kg)        DALCA             Plan              Limit

 

Empty Weight                                  116,570 

Payload                                                7,788 

Zero Fuel Weight                   Limit 124,358                209,240 

Fuel                                                   52,338                 117,162 

Ramp Weight                                  176,696                 287,125 

Take-Off Weight                             176,246                 285,990 

Landing Weight                              134,785                 222,940 

Underload                                         84,882                 Lim ZFW


 

As you can see RELEASE FUEL is 52,338 kgs, round up to 53,000 kgs ok?

 

I can't understand why I always get negative EXTRA TIME and consequent INSUFFICIENT FUEL warning into WEIGHT INIT page.

 

If I add more extra fuel (2-3000 kgs) situation doesn't change, always negative value in EXTRA TIME.

 

 

1) so is there something wrong in MD11 burning fuel template or I am missing something?

 

2) can someone share its own topcat and pfpx template for MD11F?

 

3) is correct insert the sum of ALTN+FINAL RESERVE (5,3) in LSK 5L FINAL/TIME field? I mean, WEIGHT INIT PAGE 2/3 already show the field ALTN and FINAL/TIME filled, may I change them?

 

4) do you load aircraft payload via TOPCAT or via MD11 Load Manager?

 

Thanks so much in advance for your help.

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I have managed to simplify fuel loading and I use fuelplanner.com. I specify departure and arrival then click loadsheet. I then look at trip fuel and note it is for 2/3 cargo. I then use the following equation to compute fuel for 3/3 cargo:

 

2/3 / Trip Fuel = 3/3 / x. I then compute x and add a margin of 15 to 25 thousand pounds of fuel. Without the margin, even though I have enough fuel to reach destination and about 15 to 20 thousand to spare, I still get insufficient fuel warmings.

 

I started to ignore the crys of insufficient fuel until this weekend when landing 31R at JFK a popup appears on the displaced threshold and I perform a missed approach but since I don't have the fuel for complete hold and resequence, I shortcut it back to the runway only to find on the dogleg my engines shutting down. I suggest it be taken seriously only to have extra fuel time.

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Did you enter the wind data in the FMC? If PFPX plans the flight with a tailwind, you could get negative Extra TIime and Insufficient Fuel warnings if you don't enter the wind data in the FMC.

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Yes, I only entered speed and wind direction, no winds aloft, and for haul flights those should be mandatory data, my fault. 

 

In the next flight I retry to better re-program FMC.

 

Would be very useful to have a tool for importing winds aloft, like in 777, but this tool can only be done by PMDG.

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You can assist the FMC in calculating fuel requirements by entering suspected upper winds forecast info into the Ret Data page on the FPlan menu in the FMC which you can get from SkyVector.com. Choose Upper Winds from the layers menu and the altitude from the little settings dialer. The fat lines are 50 knots, the skinny lines are 10 knots and a half line is 5 knots. The flags that appear in the upper winds display show which direction from which the wind is blowing.

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