Is the fuel planner underestimating fuel required?

[Marty47 35]

I am using the fuel planner in advanced mode. copying all details for weather, FL PAX numbers etc into the planner and generating the load sheet. And twice now I'm running out of fuel before I reach my destination in the A318.

I have a tail wind, using a cost index of 30. flying in managed mode

Is the fuel planner wrong ? or could I be doing something wrong?

I have been flying some segments of my journey at x4, could that cause fuel burn issues?

[Marty47 35]

This might be another issue. I have no fuel but this display says I still have 2880kg FOB 

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[DaveCT2003 2553]

I'm going to let someone else help you with this, but in the meantime there is a lot of information that we need from you if we're to look at this.

 

Complete Route including SIDs and STARs, the exact loadout (screen shot of the Advanced Mode of the Fuel Planner) of what you used for your flight - and all of this has to be for the past flight you're referencing or a new flight on which you experienced the same issue.

 

Also, how are you calculating the information for the Fuel Planner's Wind Speed and Direction?

 

The above info will help us look at this for you.

 

Best wishes.

 

 

 

[bill3810 109]

For now I recommend using  SimBrief.  Create an aircraft in Simbrief with the exact, BEW, MTOW, MLW, MZFW, MAX Fuel Capacity and Max Passengers as determined from the Fuel Planner.  Then use that aircraft in Sim Brief to plan your flight.  Once it spits out the Fuel Required, then transfer that data from Sim Brief to the Fuel planner and save it.  It is almost exact.  Always carry a little extra or create a 2-5% fuel bias for safety margin.

 

In the Fuel Planner:  The easiest way to do it is match the fuel then adjust the pax/cargo slider to get the ZFW to match Sim Brief and you're finished.  Adjust your CG slider for -.5 to -.9% and upload the figures.  Who cares if the pax and bags aren't exact they aren't back there anyway, unless that helps you sleep better at night. ZFW,FUEL and CG done!

[Marty47 35]

Dave,

I'll try to give as much of the info your after as I can:

 

See the screen shot from simbrief which shows the routing i used. I can not remember which sid/ star I used, but what ever it was was pretty straight forward and didn't add any extra distance.

I have added a shot of the fuel planner, I cannot remember the exact weather I entered but these values would've been pretty close.

I export flight plan from simbrief and then load it into Active Sky. I use the average winds from the briefing page and enter these into the aerosoft fuel planner

 

I landed with 1% fuel remaining and during taxiing one of the engines shut down due to lack of fuel.

 

On another note I noticed that FOB (Fuel On Board) display reduces normally during flight until 2880 and then just stays at 2880 kg

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[Aerosoft Team [Inactive Account] 51558]

Keep in mind that the fuel planner does not use the flight plan but a direct route.  The 2880 is an known bug.

[bill3810 109]

Did you load the fuel based on the fuel planner or Sim Brief?

[DaveCT2003 2553]

Thanks so much for the information.

 

Bill is absolutely correct about the hows and whys (he should be, as he flies airliners for a living), and as the Boss said the 2.88kg is a known bug that is on the list to be corrected.

 

Given that you were flying a long distance, there are all sorts of things that could have affected your fuel burn, and thus your fuel calculations.  But this is terribly difficult to analyze given all the variables. 

 

Maybe on your next flight you could take screen shots of everything and we could take a look at that

 

Thanks again for reporting!

 

 

[Aerosoft Team [Inactive Account] 51558]

I have the 2880 bug moved up to the highest status.

[Marty47 35]

Hi guys thanks for your replies.

I realise the fuel planner is a direct route. I always adjust the distance in the fuel planner based on what simbrief says anyways.

I haven't used simbrief to calculate fuel. I just assumed that the fuel planner would be more accurate as it is (i assume) built specifically for the plane I'm flying.

I just adjust all the variables within the fuel planner to match what simbrief says for the route and active sky for the weather and then let the planner calculate fuel and I load the plane based on that.

 

I have had 2 flights where I have either run out of fuel in flight or just after landing. The flight last night was close too but I finished up with about 4% remaining. I did use your old fsx airbusses in the same way and never noticed any fuel issues.

 

i will try using simbrief's estimation for fuel and see how that compares 

 

And Bill thanks for your info. I had never worked out how to create an aircraft in simbrief. I had always just used the a318 that is already in the list. 

 

 

[meccadom 2]

Reference edited post from above:

On 10/7/2018 at 2:20 PM, bill3810 said:

For now I recommend using  SimBrief.  Create an aircraft in Simbrief with the exact, BEW, MTOW, MLW, MZFW, MAX Fuel Capacity and Max Passengers as determined from the Fuel Planner.  Then use that aircraft in Sim Brief to plan your flight.  Once it spits out the Fuel Required, then transfer that data from Sim Brief to the Fuel planner and save it.  It is almost exact.  Always carry a little extra or create a 2-5% fuel bias for safety margin.

 

In the Fuel Planner:  The easiest way to do it is match the fuel then adjust the pax/cargo slider to get the ZFW to match Sim Brief and you're finished.  Adjust your CG slider for -.5 to -.9% and upload the figures.  Who cares if the pax and bags aren't exact they aren't back there anyway, unless that helps you sleep better at night. ZFW,FUEL and CG done!

 

What does BEW stand for?

 

When I select the A320 in P3D, are these values from step-by-step vol 6 the values built into the default aircraft I choose to use?  Or do I have to modify them somehow?

A320:
Empty weight 41.243 kg
Payload 8.921 kg
Zero Fuel Weight 50.164 kg
Fuel 7.615 kg
Gross Weight 57.779 kg

 

I don't understand the paragraph f\about the fuel planner. Which slider is used to achieve this, pax or cargo?  I would appreciate any further assistance or links that would help me to understand these relationships.  

Thanks

Dom

 

[bill3810 109]

Ok so before you read any further.

 

Is the Fuel Planner Accurate?  No it's not at the moment but we can change this, however it's not high priority right now.  The fuel planner will be short on fuel and it gets worse the longer you fly.

 

Is it the best tool to use?  No, use Sim Brief along with the fuel planner.

 

What is it good for at the moment?  After you calculate your data via Sim Brief you can use the Fuel Planner to load the aircraft according to Sim Brief and upload that to the sim.

 

If you want more information on weights and how to do the above read further.

 

Concerning your question on the weights:

 

EW or  Basic Empty weight is:  No Pax, No Bags or Cargo just the weight of the plane empty.

ZFW or Zero Fuel Weight:  Include the Payload (Pax, Bags & Cargo) and no fuel

Ramp Weight or Taxi Weight:  BEW + Payload + Fuel

TO Weight = Ramp Weight or TAxi Weight - Taxi Fuel

Landing Weight = Takeoff weight - Trip Fuel

 

You can find these numbers in the fuel planner by adjusting the sliders according to what I said above and then moving one slider until the associated number turns red.  For Example:

 

If you want to know the MAX Zero Fuel Weight, Take all of the fuel off of the aircraft then increase the Pax / Baggage slider until the ZFW number in the fuel planner turns red.  There's your number for the Max, watch the KG/LBS setting!

 

Honestly the best bet is to create an aircraft in Sim Brief then modify the numbers in sim brief with these numbers.

 

Sim brief is Extremely Accurate and is a complete Dispatch planning system and I don't use anything else, there is no reason, it literally is just too easy.  I even have PFPX and by the time I open that up and get to the correct screen, Simbrief has planned my flight, given me weather, notams, routing and all the planning and monitoring data i need for my flight, this can even be uploaded to your sim with the right add on available on the site for free.  Too easy!

 

So what I do is after I plan the flight with Sim Brief what I do is go into the Fuel Planner, Select the correct aircraft then adjust the Loading Sliders to give me the correct Zero Fuel weight as calculated by Sim Brief, Then I add the fuel Sim Brief calculated, Adjust the CG slider .5 - 1.0 down is good and then upload it to the aircraft, it is done at that point.

 

Once you have an aircraft setup in Simbrief, this entire process can be done in less than 3 minutes.  Print your OFP and off you go.

 

Sorry for the long winded answer.

[meccadom 2]

Thanks for the discourse, but still have some difficulty grasping this.  Can you please look at the attached Simbrief plan and show this to me graphically in FuelPlanner advanced mode so that I may see where the data is entered? 

thanks

Dom

EBBREGLL_PDF_1539972099.pdf

[jd_jay 3]

22 hours ago, bill3810 said:

 

Sorry for the long winded answer.

 

Just want to say thank you for this reply.  Have just been browsing through the forum and stumbled across this, a response to someones post but very informative in general.

[meccadom 2]

20 hours ago, meccadom said:

Thanks for the discourse, but still have some difficulty grasping this.  Can you please look at the attached Simbrief plan and show this to me graphically in FuelPlanner advanced mode so that I may see where the data is entered? 

thanks

Dom

EBBREGLL_PDF_1539972099.pdf

 

[DaveCT2003 2553]

On 10/18/2018 at 4:15 PM, bill3810 said:

Ok so before you read any further.

 

Is the Fuel Planner Accurate?  No it's not at the moment but we can change this, however it's not high priority right now.  The fuel planner will be short on fuel and it gets worse the longer you fly.

 

Is it the best tool to use?  No, use Sim Brief along with the fuel planner.

 

What is it good for at the moment?  After you calculate your data via Sim Brief you can use the Fuel Planner to load the aircraft according to Sim Brief and upload that to the sim.

 

If you want more information on weights and how to do the above read further.

 

Concerning your question on the weights:

 

EW or  Basic Empty weight is:  No Pax, No Bags or Cargo just the weight of the plane empty.

ZFW or Zero Fuel Weight:  Include the Payload (Pax, Bags & Cargo) and no fuel

Ramp Weight or Taxi Weight:  BEW + Payload + Fuel

TO Weight = Ramp Weight or TAxi Weight - Taxi Fuel

Landing Weight = Takeoff weight - Trip Fuel

 

You can find these numbers in the fuel planner by adjusting the sliders according to what I said above and then moving one slider until the associated number turns red.  For Example:

 

If you want to know the MAX Zero Fuel Weight, Take all of the fuel off of the aircraft then increase the Pax / Baggage slider until the ZFW number in the fuel planner turns red.  There's your number for the Max, watch the KG/LBS setting!

 

Honestly the best bet is to create an aircraft in Sim Brief then modify the numbers in sim brief with these numbers.

 

Sim brief is Extremely Accurate and is a complete Dispatch planning system and I don't use anything else, there is no reason, it literally is just too easy.  I even have PFPX and by the time I open that up and get to the correct screen, Simbrief has planned my flight, given me weather, notams, routing and all the planning and monitoring data i need for my flight, this can even be uploaded to your sim with the right add on available on the site for free.  Too easy!

 

So what I do is after I plan the flight with Sim Brief what I do is go into the Fuel Planner, Select the correct aircraft then adjust the Loading Sliders to give me the correct Zero Fuel weight as calculated by Sim Brief, Then I add the fuel Sim Brief calculated, Adjust the CG slider .5 - 1.0 down is good and then upload it to the aircraft, it is done at that point.

 

Once you have an aircraft setup in Simbrief, this entire process can be done in less than 3 minutes.  Print your OFP and off you go.

 

Sorry for the long winded answer.

 

Excellent work Bill, great answer my friend!

 

 

[bill3810 109]

On 10/20/2018 at 6:08 PM, meccadom said:

 

 

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Zero Fuel Weights - Match that with the OFP by moving the sliders until the two ZFW match.

Orange Items - you can match them if you like or you can just adjust the trip distance to make the BlockFuel on the OFP match the Total Fuel on the Fuel Planner at the bottom right.

Blue Box is the Block Fuel - Just use the Trip Distance Slider in Bold Red at the top right and adjust that until your Total Fuel Matches SIM BRIEFS Block Fuel.

Green Box - is the average winds.

 

The simplest method is a 1, 2, 3 approach.  Do this every Time and you will not have any problems.

 

1.  Enter Dep Arr Airports

2.  Match the ZFW or Zero Fuel Weights

3.  Adjust the trip distance so the Block Fuel in the aircraft matches the block fuel on the OFP.

4.  Adjust the CG

5.  Generate Loadsheet

 

Lastly when you are creating your flight plans In Sim Brief I recommend setting a Fuel Factor as follows until we can get this fuel burn ironed out.

 

SIM BRIEF - FUEL FACTOR (Based on Planned Flight Time.)

 

1-2 Hours + 5%

3-4 Hours + 10%

5 + Hours + 20%

 

Note:  Once you do set a Fuel Factor you can find that in your OFP by going to the AVG WIND on the right and move down until you see Fuel Bias = P00.0  or what ever you eventually set it to.

 

 

[Flavio1 64]

Many thanks Bill for your tips,

I have created the aircrafts in Sim Brief using these data (found in Aircraft_xxx_xxx.xml) that could be useful for other pilots

(let me know if there some errors)

 

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and now I will use your method for fuel planning.