Can't update aircraft.cfg settings into FSX (no, this is not about saving the file)

[pedrornunes96]

Hello everyone!

 

I keep running into bad luck the past few weeks... Being an aviation and FS enthusiast I am running low on patience and unfortunately had to come here and ask for your help.

 

As part of my piloting experience, it is normal that I need to tweak many aircraft settings in the aircraft.cfg, to make them more realistic. The last one I have successfully updated was a cruise_lift_scalar and fuel_flow_scalar for my DC-10 fleet, some 2 weeks ago. Since then I have taken non-FS related tasks and only since last weekend have I started on a new aircraft (an L-1011).

 

The goal was to set a new cruise_lift_scalar (1.0 to 1.7) and adjust the fuel flow with this new parameter. I've done this dozens of times before, and I thought I wouldn't have any problems whatsoever. However this was not the case. I noticed that even if I changed the fuel_flow_scalar by units, the damn engine PPH always remained the same: 7046lb/h (at FL350 mach .81, weight=466000lb). If I revert the cruise_lift_scalar back to 1.0, the ffs changes back to 8914lb/h (the original value). I have tried changing the fuel_flow_scalar in other aircraft, and it also appears to be happening to every other aircraft in my sim, as if it kept some old scalars from 2 weeks ago and now they just won't update.

 

Does this have to do with some setting in the fsx.cfg? What about administrator settings (I have tried to change permissions to allow everything to be edited, but to no avail)? Why does this only affect the fuel_flow_scalar parameter and not every other parameter in the aircraft.cfg?

 

I appreciate any reply...

 

Merry Christmas

[PhantomTweak]

According to the FSDeveloper forums, and they're a heck-uv-alot smarter than I, you want to adjust fuel_flow_GAIN, not the scalar, to accomplish what you desire.

It interfaces with the .air file 15XX series tables. Also, the ThrustSpecificFuelConsumption has a great effect.

If you are trying to adjust the fuel usage during cruise at altitude, you adjust the inlet_area parameter. Bigger=LESS fuel used, suprisingly.

 

I won't even get into adjusting the .air file tables for jet engines. That's a can be a real can of worms, and I don't feel like getting brain cramps about it right now. And I do, every time. This table affects that table, but not the other table UNLESS thus-and-such happens or during this and this...it just goes on and on. I get headaches just thinking about getting headaches about it.

 

Have fun, and a very Merry Christmas to you :D

Pat☺

[mallcott]

Reiterating what PhantomTweak just told you, the .air file is what you need to be tweaking, NOT the aircraft.cfg file.

 

Be prepared for a LOT of study of the .air file...

[pedrornunes96]

Ok, I have taken a new course of action - not to trust the gauge that indicates the PPH - and guess what, all the times that I have tweaked the fuel_flow_scalar and have successfully configured aircraft in the past, I was lucky, wholly because either:

1) I tested the fuel consumption via FMS (that shows the final fuel calculation at a certain destination);

2) I tested the A/C via PPH indication in a different gauge, not sure why but it showed variation in the PPH after making changes to the ffs parameter.

 

Taking that in consideration, there was never a problem with my sim, just that particular gauge.

 

Now, taking your consideration, I actually never thought of that :p

I always thought that for me to change the fuel consumption, I would either change settings that apply to the engine, nominately the fuel_flow_scalar and [turbineenginedata] parameters, or aerodynamic parameters of the aircraft, Cd_0, Cl_0, etc (I actually have tweaked the Cd_0 a lot in .air files...)

 

But I never thought about the fuel_flow_gain, I honestly don't understand the definition of this parameter, neither have tested its effects on fuel consumption, but I will certainly take a look at FSDeveloper forums and see more about it. I'm not going to change the inlet area, I just input the real data from this website (diameter of the fan), but sounds counter-intuitive that bigger=Less, because at higher altitudes wouldn't that produce more drag? I also use data from that source to get the TSFC and from there change other parameters to accomplish the fuel consumption that I desire...

 

Thanks for the response and merry xmas!