Default fuel % in tanks

I've been Googling this for some while but have arrived at no answer so far. I wonder if anyone knows how to set things up so that all fuel tanks in all 3rd. party aircraft load with, say, 50% fuel in them?

With the C172 at KSEA as the default flight, the left and right fuel tanks of all aircraft open with 50% fuel, as that is how things are in the default .flt file (flightsim.flt):

[Fuel.0]
TankSelector=All
TankSelector1=All
Center=50
LeftMain=50
RightMain=50
LeftAux=50
RightAux=50
LeftTip=50
RightTip=50
Center 2=50
Center 3=50
External 1=100
External 2=100

(That's my edit, done years ago - to get 50% in the Cessna by default rather than 100%: I think all values are normally at 100%).

But of course since the C172 only has those two tanks, the other tanks are ignored - not just in the C172 but all addon aircraft (and least the 'freebies' like Posky, iFDG and so on) load with all fuel tanks, left and right apart, at 100% fuel, despite the above settings. Changing the values for any tank other than the left and right tanks makes no difference to what loads in the sim, whatever the plane you load up.

Other than changing the default flight to an aircraft which possesses all the tanks as listed as above (would that work? I wouldn't want to do it in any case), does anyone know of a way to manage this - to have every tank at 50% full (or 50% empty, if you prefer!) when you load an aircraft? I suspect it can probably only be done by saving a flight for every aircraft type and loading that .flt file after start-up. Not very 'elegant'...

(I tried, just as an experiment, adding references to all the other tanks to the [fuel] section of the c172 aircraft.cfg file - but it made no difference: only two tanks appear in the FS9 fuel menu. I stopped short of editing the .air file... Maybe it is hard coded in the model??).

In the 'Create A Flight' screen, load the desired Airplane, then click on 'Fuel & Payload'. Click on the 'Change Fuel' button, and it will allow you to Select the amount of Fuel, both in % and in # or Gallons.

Alan :pilot:

Don't feel like the "Lone Stranger" there, Tonto. Mine is set up exactly like yours with the default Baron58 instead. Choosing other aircraft will have 100% in the other tanks and must be adjusted for each individual aircraft at the start of every flight. Don't know of a way to have them all at 50% other than using an aircraft with a maximum amount of fuel tanks set at 50% and using it as the "default flight".

Agree with ViperPilot2!

You are right in thinking the air file is where you set the fuel amount. The trick is to set the number of gallons (for each tank) in the air file's (fuel) sections (525 thru 535) and then comment out the (fuel) section in aircraft.cfg. The air file will then WRITE the fuel section into the aircraft.cfg for you (scroll to bottom of aircraft.cfg to find it) with '50%' of fuel.

Of course some aircraft don't have the 525 thru 535 sections. But you can add them to air file. Then from then on when you load the 'edited' aircraft they will have 100% fuel load BUT but will only have 'XXX' amount of gallons per tank, as set in air file (do the math to set at 50%). This will not ever change. Unless you comment the cfg (fuel) section AND edit the air file (again).

Chuck B

Napamule

Don't feel like the "Lone Stranger" there, Tonto. Mine is set up exactly like yours with the default Baron58 instead. Choosing other aircraft will have 100% in the other tanks and must be adjusted for each individual aircraft at the start of every flight. Don't know of a way to have them all at 50% other than using an aircraft with a maximum amount of fuel tanks set at 50% and using it as the "default flight".

 

Agree with ViperPilot2!

Part of "flying" is deciding the fuel load for each flight. Otherwise you can possibly "tanks a lot" or run out. Neither is a good thing. How much trouble is it to decide on and adjust your fuel and other payload as needed anyway?

To be honest, if you're not familiar with altering the .air File, I wouldn't do it; you could be opening up a real can of worms and inadvertently throw the other Flight Dynamics off.

That's why the Fuel and Payload screen is there... to adjust Fuel & Payload without throwing anything else out of kilter.

Alan :pilot:

No, I agree. I am reasonably familiar with certain parameters of the air file and edit them with no problem, but I don't know what this might do, so had decided, as I say, to leave well alone. The idea was simply to save my having to go into the fuel menu every flight, but it's no big deal!

That said, so long as the original file is backed up, no harm could be done. Even so...

The unanswered question is WHY you want/need 50% fuel on all your aircraft fuel tanks??

At any rate it will take 1 minute per aircraft to comment out the (fuel) section in aircraft cfg (then 'Save') and then modify the fuel tank values in the air file (then 'Save'). Too easy?

Chuck B

Napamule

At any rate it will take 1 minute per aircraft to comment out the (fuel) section in aircraft cfg (then 'Save') and then modify the fuel tank values in the air file (then 'Save').

I can certainly give that a try... but as I say, as far as I can see, all the fuel tanks are not represented in the .air file.. an aircraft with say 6 tanks does not have six entries, just three, at the least the couple I tried yesterday. So maybe I would have to add fuel tanks from scratch to the air file (not that hard to do, but I'd have to investigate that a bit further first)

OK! Now we are getting somewhere (hehe). Look in air file of similar size aircraft and copy then paste section(s) from one air file to the other.

Open both air files, set side by side (half screen each) and click on section (will be highlighted), then Right Click on it, then click 'Copy to Clipboard'.

Now move mouse to other air file, right click on any square (vertical column) and click 'Add From Clipboard'. Copy is done. Then set the amount (50% - do the math first), then do 'Save'. You can verify at 'Aircraft/Fuel and Payload'.

You then need to comment out the (fuel) section in aircraft cfg so the air file can write a new (fuel) section in cfg with all the tanks and the amounts as they are in the air file. This will 'happen' when you load the aircraft. (Scroll down to bottom of cfg to find new (fuel) section). Only takes a minute per aircraft. Life is good.

Chuck B

Napamule

I'm all for tweaking, if you tweak an air file save/rename the original then tweak the copy, see what happens, if it fails you still have the original.

Also what about the times we use an air file from a different aircraft to make it fly better?

As napamule mentioned earlier, the figure 50 which you enter into the aircraft.cfg [Fuel] section changes the total capacity of that tank to 50 gallons, not 50 percent of whatever capacity it was already. I would recommend the following:

Change the default C172's fuel load to 50% in the Fuel and Payload settings screen and save the flight as default.

Open your chosen airliner's aircraft.cfg, go to the [Fuel] section and add up the total number of gallons in each tank, then divide by two to get the capacity for each of two tanks only.

Now change the airliner's tanks to LeftMain and RightMain only, and enter the new capacity for each tank, the other figures after each entry can all be 0's.

You'll also need to add Fuel Left Main Tank and Fuel Right Main Tank entries to the .air file if there aren't any in there already. Copy them from the C172 .air file if needed, change all the offsets to 0 and just enter the same capacity as you did in the aircraft.cfg.

With this method you will still have the correct fuel capacity and weight for the aircraft, but some of the fuel selectors and pumps will now be redundant. In a payware model this may trigger warnings and failures, I would only do this with freeware models which don't have sophisticated fuel management systems.

Yes, I will give it a try when I get a moment (I am away for a few days now) - and then post back. It's not a huge deal in the sim of course, but it would be good to see if I can get it to work!

Thanks for the info...