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Fuel Error?

Posted: October 15th, 2016, 11:22 am
by UAL152 Tom Hartigan
First of all I want to say Simbrief is probably the coolest thing I have come across in my 10+ years of VA flying. I noticed an issue with the fuel it gave me for a flight from KLAX - EGLL. Here is the breakdown:

TRIP LHR 128530 0936
CONT 5% 6427 0026
ALTN MAN 7047 0032
FINRES 5697 0030
ETOPS/ETP 0 0000
MINIMUM T/OFF FUEL 147701 1105
EXTRA 0 0000
T/OFF FUEL 147701 1105
TAXI LAX 700 0010

Now I went by these numbers and kept getting the "Insufficient Fuel" warning coming up in my FMC. I checked a couple of other planning sources and they are all calling for at least 200,000 lbs of fuel. Am I just missing something here, or is this an error on Simbrief's end?

Re: Fuel Error?

Posted: October 17th, 2016, 8:10 am
by UAL008 Keith Rocke
Tom. What I didn't see in your post is... which aircraft you chose to fly within Simbrief. Nonetheless, here are a couple tidbits I do regarding fuel load...
  • create/load route on Left-hand FMS
    display PROGRESS PAGE on Right-hand FMS
    make sure there are no DISCONTINUITIES in the route (LH-FMS). DISCOS are a problem to resolve
    research (separately) the fuel burn of the plane you want to fly... climb/cruise/descent... not forgetting taxi fuel burn
    add 10% of predicted trip fuel to overall load
    add (something) for HOLDING
    add (something) for ALTERNATE
    we already mentioned TAXI
    the APU drinks JET-A just sitting at the gate too
    factor in winds aloft... can't forget mother nature... eastbound? tailwind? westbound? nosebleed?
    and as a failsafe... decide to arrive at the destination with 10+k pounds (or convert to kilos if that's your standard)
... that is a (IMHO) better prediction of the true numbers.

The B77L/W has a cool payload and fuel load entry build into the FMS... and the PROGRESS PAGE verifies the destination fuel.

I've been cooking flight plan routes within Simbrief for forever and (recently) started paying attention to Simbrief's fuel calculations... and actually using the numbers when flying the iFly B700 Series of aircraft. XREFing my separate (above) methods with the numbers that Simbrief spits out, I've found NO life or death differences between the two sets of numbers.

When I take the Trip7 for a spin, I (only) aim for 10k+/- pounds by closing ALL DISCOs in the route and making sure the PROGRESS page verifies the comfort margin.

Your mileage may vary using my methods. But, just like there are a variety of routes you can build within Simbrief, there are a variety of (FREE) fuel planners you can try.

I've been at this sim thingy for just as long as you have been. There are NO surprises anymore... just warm, soft cushions and Preparation-H :lol:

Oh! Another thing you might want to review (and possibly manipulate?) in the FMS? Check the PERFormance page. There you can/may have the option of selecting the PERCENT% of fuel at destination? Let's say you select 10%... and get the INSUFFICIENT FUEL warning? Try lowering that %%% and see if the warning goes away? Keep tweaking that %%% until - if you get to 0% and the warning still displays... you're gonna increase vUAL's Insurance Premiums (if you're airborne)... need to land ASAP or glide-for-life. If you're still at the gate? Call the dispatcher and get some more JET-A into the fuel cells. :roll:

Hell! One more thing at your disposal to tweak? Your CI (Cost Index). This single puppy is what drives an airplane for profitability and is KEY. Ex: B737 Series? CI=30... B747Series? CI=300... B777Series? CI=100


Re: Fuel Error?

Posted: October 24th, 2016, 10:54 am
by UAL044 Kevin Finch
I usually skip down to p. 05 of what SimBrief spits out (current flight below, BOLD/colour is mine) and load the Cost Index and gate fuel, and I'm good to go. Maybe a little heavy, even. I'll either use the vendor supplied utility to load the aircraft or go the FMC route with the PMDG 737.

UAL 0014 SBGR/LEBL 24.OCT.2016/1000Z
************* COMPUTER FLIGHT PLAN *************
14 24 SBGR LEBL LEMD B747-400 ALL 484
BURN 2317 09.33 PYLD 1315 FCST .... / ....
ALTN LEMD 0208 00.49 ZFW 5350 5350 DRAG/FF P0.0 P0.0
RSV 05PCT 0116 00.32 FOB 2830 3836 AVG W/COMP P023
RSV 45MIN 0169 00.45
CONT 0000 00.00 TOW 8160 8617 AVG OAT P10
ETOPS ADD 0000 00.00 BURN 2317 ADL BO/1000 0320
MIN FUEL 2810 11.40 LGW 5843 6300 OUT 10.00Z OFF 10.20Z
TAXI 0020 00.20 FUEL OVER DEST 0493 2.06 ...... ......
EXTRA 0000 00.00 FUEL OVER ALTN 0285 1.17 ON 19.53Z IN 20.01Z
GATE FUEL 2830 12.00

Re: Fuel Error?

Posted: January 31st, 2018, 4:20 pm
by UAL636 Victor Cabrales
Albeit a bit of an old post I wanted to offer my calculation on the fuel using Simbrief.

When I calculate my flight I always calculate 10% extra for any "unforseen" issues (simulated of course), and I calculate 10 mins of taxi out and depending on the airport....for example KMCO is a huge airport and it can easily take me 12 to 15 minutes to taxi from rwy 35R to Airside 1 depending on the landing configuration of 35L (to cross). However if I am landing at KEWR then I only calculate for 8 mins of taxi. Now, I must confess that in order to make sure I have enough fuel I also run my numbers from Simbrief against the Aerosoft Fuel Configurator. 95% of the time they are very darn close to each other. Take in to consideration your weight in pax and cargo as well as the ZFW of the AC you are using. Let me know if you are still having issues with the fuel. I can help you figure it out.