Modifications to various drag and thrust parameters, not a major overhaul of the original FDE by CS which is already excellent.

Features include:

1. ability to apply realistic EPR settings in all flight phases
2. realistic takeoff power and climb performance
3. lose less airspeed on idle-thrust descent
4. thust required to taxi reduced to about 39% n1
5. realistic fuel burn rate

___________________________________________________
current version 1.1 (July 31)
http://www.mediafire.com/?432i9k8s6zg4489

Hi Bud,

great work !  Thanks a lot for sharing it !  :)
I think CS is very happy, that You've done this hard job for them.   ;)

Thanks again
   and best regards !
         Dietmar

Thanks Dietmar. The flight model by CS really is excellent, I only edited a few parameters.

Hi Bud,

Thanks for your hard work on this - unfortunately the link is not working for me. Any chance you could email it to   steve.amsden@yahoo.co.uk.

Thanks again

Steve

Hi,

Just curious as to what changes were made to the .air file?

Thanks

wrote on Jun 10^th, 2012 at 6:08am:

Hi, Just curious as to what changes were made to the .air file? Thanks

Hi Paul,

Reduced zero-lift-drag-coefficient. In my search for better descent rate, I found that this has more affect on airspeed in descent than inlet_area (ram drag) and parasite drag.

Adjusted thrust factor vs cN1.

Just a question. I've made some changes to the aircraft cfg before.
Wonder what induced_drag_scalar  should be.

I now have         induced_drag_scalar    = 0.785

Best regards
Mikael

Induced drag relates to lift and pitch angle. But it also has more of an effect on cruise than I thought it would. After reducing zero lift drag in the .air file I was able to leave induced drag at the default 1.0

With a value of .785 you should have unrealistic EPR and N1 (too low) during climb, level flight, and final approach.

Thank you Bud!

I could not find wich value it should be for your FDE mod.

But now I know thank you for your fast reply!

regards
Mikael

Is this air file for both 200 and ADV models?

Hmmm, good question. I only have the 200. I don't know if CS gave the 200 ADV it's own flight model or if it's only a visual expansion.

Hi Bud,

I just checked the air file. It's the same as the 200

Thanks for your efforts.  :) Please correct me if I'm wrong, but when using the mod, the gauge from fsxpaul has to be adjusted, right? Since both of you are reading this thread, I hope the question is ok.

CoolP wrote on Jun 12^th, 2012 at 3:01am:

Thanks for your efforts.  :) Please correct me if I'm wrong, but when using the mod, the gauge from fsxpaul has to be adjusted, right? Since both of you are reading this thread, I hope the question is ok.

Yes the V-One gauge needs the Opt EPR offset changed.

Did a test flight and came up with -0.123 which will get the EPR real close.

1. Edit the oppropriate v-one.xml file (right mouse click on filename, then choose 'Edit'. Do not choose 'Open').
2. In section 'Initial Vars' towards the bottom of the file, change the following:
    FROM: 0.0 (>L:OptEprOffset,number )
    TO: -0.123 (>L:OptEprOffset,number )
3. Save your changes.

Thanks, Paul. Now that's what I call a fast service.  :)

Dear Paul,
thanks for your mod. It works really well with the 200.
However, I'm having a bit of a problem with the ADV (using the exactly same mod). It is very slow, needs lots of thrust to taxi and also a long runway.

For example:
I did a high-altitude flight: Quito - Guayaquil with that marvellous AeroGal livery:
Total weight according to ACE: approx. 9000 kg
Fuel: approx. 50% according to FSX
Airport: SEQU, altitude 9000 feet, rwy35
I couldn't lift the plane off the runway. I then increased the static thrust (FDE) to 18900. With this value it was possible to take off, but very slowly using all of the runway and barely managing a right bank to avoid the mountain in front.

I've noticed that the 200ADV is heavier according to the FDE. And maybe my plane was just too heavy for that altitude?
Would you maybe have some mod values tailored for the ADV?
Thanks
Chris

Chris, just to clarity, the FDE (Flight Dynamics Envelope) includes the aircraft.cfg and the .air file.

If the ADV installation includes it's own .air file, rather than aliasing the csx732.air file from the main CS_B737-200 folder, then the ADV aircraft.cfg probably says something other than

[fltsim.1]
title= . . .
sim=csx732
model=
panel=
sound=
texture=
. . .
. . .

If that's the case then it's only applying the modified aircraft.cfg values for drag and thrust without applying the modified csx732.air values, which will result in being very underpowered.

I don't have the ADV expansion, just the original 200, so I can't do any editing with the ADV.
How does the ADV perform without any mod?

Ouch!!! The .air file! Yes, that's it. I forgot to copy it into the ADV folder. I'll try to take off at SEQU again with the same values and get back to you.
Thanks

Chris the Swiss wrote on Jul 1^st, 2012 at 10:20am:

Ouch!!! The .air file! Yes, that's it. I forgot to copy it into the ADV folder. I'll try to take off at SEQU again with the same values and get back to you. Thanks

If there is an .air file specific to the ADV then more than likely it contains different values for control surfaces, flight dynamics and possibly thrust. There's a possibility the results might not be very good combining the original 200 .air with the ADV .cfg.

FDE updated in post #1.

Improved all around, most noticeable difference is probably better idle descent.
My final update until the 737-200 update is released by CS.

Thanks for update 1.4

Is "ThrustSpecificFuelConsumption" commented out on purpose in the readme or it's a typo?

speck wrote on Jul 20^th, 2012 at 4:34pm:

Thanks for update 1.4 Is "ThrustSpecificFuelConsumption" commented out on purpose in the readme or it's a typo?

Yes that was intentionally commented out.

Update: fuel consumption has finally been worked out, so the "ThrustSpecificFuelConsumption" is now required and a couple other values have changed in the .cfg, these are listed in the 1.05 readme.txt.

Paul,
Yes the V-One gauge needs the Opt EPR offset changed.

Did a test flight and came up with -0.123 which will get the EPR real close.

1. Edit the oppropriate v-one.xml file (right mouse click on filename, then choose 'Edit'. Do not choose 'Open').
2. In section 'Initial Vars' towards the bottom of the file, change the following:
    FROM: 0.0 (>L:OptEprOffset,number )
    TO: -0.123 (>L:OptEprOffset,number )
3. Save your changes
_________________________________

I edit V-one.xml file, but I cannot find "Initial Vars" section. :-[ :-[
I am sure it is there, I need help

Thanks
Sanal

Here's what the whole chapter looks like before the changes.
[code]      <Element><Select><Value>
     (L:Init_Vals,bool) 0 ==
           if{
                 (A:FUEL TOTAL QUANTITY WEIGHT, pound) (&gt;L:Fuel_Total_Initial, pound)
                 1 (&gt;L:Init_Vals,bool)
                 3.0 (&gt;L:CgOffset,number)
                 0.0 (&gt;L:OptEprOffset,number )
                 0 (&gt;L:OptAltOffset,number)
           }

           (A:FUEL TOTAL QUANTITY WEIGHT, pound) (&gt;L:Fuel_Total_Current, pound)
           (L:Fuel_Total_Initial, pound) (L:Fuel_Total_Current, pound) - (&gt;L:Fuel_Total_Consume, pound)

           </Value></Select></Element>
     </Element>[/code]
Perhaps it's best to pick a unique expression like OptEprOffset,number then open the file in notepad and use Ctrl-F to find it within the code. This should lead you the way.  :)

CoolP wrote on Jul 22^nd, 2012 at 8:23pm:

Here's what the whole chapter looks like before the changes. [code]      <Element><Select><Value>      (L:Init_Vals,bool) 0 ==            if{                  (A:FUEL TOTAL QUANTITY WEIGHT, pound) (&gt;L:Fuel_Total_Initial, pound)                  1 (&gt;L:Init_Vals,bool)                  3.0 (&gt;L:CgOffset,number)                  0.0 (&gt;L:OptEprOffset,number )                  0 (&gt;L:OptAltOffset,number)            }            (A:FUEL TOTAL QUANTITY WEIGHT, pound) (&gt;L:Fuel_Total_Current, pound)            (L:Fuel_Total_Initial, pound) (L:Fuel_Total_Current, pound) - (&gt;L:Fuel_Total_Consume, pound)            </Value></Select></Element>      </Element>[/code] Perhaps it's best to pick a unique expression like OptEprOffset,number then open the file in notepad and use Ctrl-F to find it within the code. This should lead you the way.  :)

Not sure why your inquiry is in this thread but...yes CoolP is correct.
Which aircraft are you trying to change? -200 or -200ADV?
It is imperative that you know which you're trying to change.
Below is the 'Element Name' I was referring to:

     <Element Name="Initial Vars">
     <Element><Select><Value>
     (L:Init_Vals,bool) 0 ==
           if{
                 (A:FUEL TOTAL QUANTITY WEIGHT, pound) (&gt;L:Fuel_Total_Initial, pound)
                 1 (&gt;L:Init_Vals,bool)
                 3.0 (&gt;L:CgOffset,number)
                 0.0 (&gt;L:OptEprOffset,number )
                 0 (&gt;L:OptAltOffset,number)
           }

           (A:FUEL TOTAL QUANTITY WEIGHT, pound) (&gt;L:Fuel_Total_Current, pound)
           (L:Fuel_Total_Initial, pound) (L:Fuel_Total_Current, pound) - (&gt;L:Fuel_Total_Consume, pound)

           </Value></Select></Element>
     </Element>

You should always exercise caution when making changes of this kind...always make a back-up copy.

Thanks . I am for 200

Did more test flights and the only thing I found unsatisfactory was a bit too much gear drag. Lowered this by 8% to get proper thrust / pitch on approach.

Changes to .air file only. Aircraft.cfg values remain the same as previous update.

File link and notes updated in post 1

I'm getting "invalid zip file" when I try to open the 31/07 version, has anyone else got this? :'(

johnwillimas wrote on Aug 1^st, 2012 at 6:30am:

I'm getting "invalid zip file" when I try to open the 31/07 version, has anyone else got this? :'(

Fixed  :D

bud7h7 wrote on Jun 8^th, 2012 at 11:42pm:

This will be the final update unless I find a way to alter spool up rate the way I want. Spool up from idle thrust should be slow, BUT once engines are stable above 50% n1 or so, when you push throttles to full, the spool up should be very fast.

I think you are looking at an inherent flaw of that FSX jet engine model. The spool up behavior is sort of reversed unless you run a lot of parameters outside of the sim. However, if there was a magic switch, let us know. I'm a fan of your work.  :)

Does anyone know if this mod is good to use with the 200C/F

Ive already had to adjust the max gross weight on the 200C/F as its to light at 11600lbs, ive changed it to 124500lbs to reflect its MTOW

gandy wrote on Aug 11^th, 2012 at 8:36am:

Does anyone know if this mod is good to use with the 200C/F

I only have the base 200 installed but I believe it will work perfectly as long as the 200 C/F uses the same .air file as the 200 (csx732.air)

[fltsim.0]
title=CS 737-200 Captain Paint0
sim=csx732
model=
panel=
sound=
. . . . .
. . . . .

sadly the C and F versions each have their own air files.

I might give it a go to see how it works.

gandy wrote on Aug 11^th, 2012 at 10:27am:

sadly the C and F versions each have their own air files. I might give it a go to see how it works.

. . . . . . . .


http://www.jasperfforde.com/toad/images/acme.jpg

bud7h7

Thanks a lot for doing this work on the 737. It is the effort of guys like yourself and the sim community that make flight simming such a rewarding pastime and the amount of work you would have done is appreciated.

I think this is a nice fix and makes the model behave sensibly like a real 737. When I first got the 737 a few days back I must admit I was quite dissapointed with its flight behaviour, which I thought was quite flaky, way too fast on acceleration, climb and descent with engine readout values that did not quite correspond with what I expected of an aircraft like this of this vintage. The 737 was always a pocket rocket but the CS intial release behaved like a pair of CFM 56's had been attached to the wings.

Off topic I know but the elevator is still way too sensitive and the cockpit wheel rolls about (backwards and forwards) incessantly in flight. In the real aeroplane and others like it these are quite firm and move slowly and do not have huge pitch change oscillations when they are moved.

I have not yet got the FD to work it just sits there toppled and the HSI is too slow and the HDG bug almost unreadable. I also get weird stuff happening with radio selection knobs. All in all the more FSX gets loaded up the worse it gets.

NOt sure if the pitch change issues can be fixed via the cfg or air files due to the interrelationship with cockpit guages and controls, I know some of this fixed up via the model files which I cannot access or change. Over to CS to do some more fine tuning.

Again thanks.

Thank you for the kind words! I have not experienced the pitch sensitivity issue you described. Unless maybe we just have different interpretations on how the aircraft should behave. If there is any turbulance at all the AP will be constantly making pitch trim adjustments, and the amount of trim wheel rotation probably makes it seem like it's trimming more than it actually is.
However on FS aircraft with overly sensitive trim (pitch moves too much with very little controler input) I reduce the trim sensitivity in the .cfg .........

elevator_trim_effectiveness = 0.9

Bud7h7 The modified AIR file fix works a treat in my view and gives me the sort of performance I would expect of the this era aeroplane and seems pretty close to the real thing, although I have never flown one for real I have flown similar vintage and sized aircraft. The take-off is more measured and climb and descent pretty well as per the book. No changes to the flight stability profile with the changes to parasite and induced drag that I could discern so it is all good so far, much better than v 1.0x cft and air files, but still all goes to make it a much better product and sim experience/

Again, Good stuff and well done.

As the for elevator sensitivity it seems it may be related to FSX v FSUIPC  and my Logitech joystick, as I like the mouse wheel control setting for trim control and it seems the FSUIPC setting may be too sensitive, that being said, I need to do a lot of reading and fiddling to get this set up to get the best out of it and that it seems may be a whole new topic and era of study.

Bud7h7 Done a few hours now with the modified FDE for the 737. A few observations. I get a loss of power generally about F160 to F240 in ISA condition which results in loss of speed back to M.50 and ROC of about 500fpm then the power comes back on and aircraft accelerates again to normal mach for the climb and climb rate. I also find that at F270 and above I get rollback and find I have to constantly adjust the power settings to maintain crusie Mach this always results in the beast going up to its speed limit then me bringing the power back again. It sits there normall and then the roll back in the N1 and N2 occurs. (Engine inlet heat and fuel heat ON).

Are the turbine/inlet scalars correct for the mod you have done It all works fine especially on take-off althought I must admist the idle RPM is a little low to my thinking?

Quote:

I get a loss of power generally about F160 to F240 in ISA condition which results in loss of speed back to M.50 and ROC of about 500fpm then the power comes back on and aircraft accelerates again to normal mach for the climb and climb rate.

I haven't seen this behavior. When you say loss of power do you mean thrust? Like reduced n1 reading?
EPR should be monitored every couple minutes during climb, and increased with altitude as required. If I takeoff with EPR 2.09 , by the time I am at FL240 I might have EPR set to 2.12 (if I'm still climbing).


Quote:

I also find that at F270 and above I get rollback and find I have to constantly adjust the power settings to maintain crusie Mach this always results in the beast going up to its speed limit then me bringing the power back again. It sits there normall and then the roll back in the N1 and N2 occurs. (Engine inlet heat and fuel heat ON).

What weather enging do you use? The roll back you're experiencing sounds to me like weather updates (winds). Headwinds/tailwind changes will obviously result in different speeds at the same power setting. Using real weather (REX) I often need to adjust thrust when the weather updates to maintain the best speed/fuel flow or even to avoid overspeed.


Quote:

Are the turbine/inlet scalars correct for the mod you have done It all works fine especially on take-off althought I must admist the idle RPM is a little low to my thinking?

The idle thrust is the same as the original FDE (should read about 33% n1 I think?)

bud7h7 wrote on Jun 8^th, 2012 at 11:42pm:

___________________________________________________ current version 1.1 (July 31)

The file I get by clicking the link provided says in its readme.txt that it's version 1.05 from 23rd July.

Could you check it? Maybe I'm missing something?

Thanks for your effort!

liser wrote on Dec 20^th, 2012 at 11:06am:

bud7h7 wrote on Jun 8th, 2012 at 11:42pm: ___________________________________________________ current version 1.1 (July 31) The file I get by clicking the link provided says in its readme.txt that it's version 1.05 from 23rd July. Could you check it? Maybe I'm missing something? Thanks for your effort!

Ah yes, I failed to update that part of the notes but the actual cfg values in the text are all the latest version (1.1)
File corrected 12/20/12

Thanks for clarifying. I thought it could be something like that, but I had the doubt.