Help tweak aircraft.cfg?

[sas550]

Hi! I'm using pmdg 737-800 aircraft cfg. My prob is that I believe it pitches down to much while making a turn. I understand that I loose lift while roll to turn but I believe it's to much.

Q. How and where can I change that behavior?

[David Rogers]

Hi Anders,

I agree - the PMDG does suffer excessive pitch sink, when in turns.

You can tweak this in aircraft.cfg's that have a [FLIGHT TUNING] section in them. I can't remember off the top of my head whether the PMDG aircraft.cfg's include a Flight Tuning section ........ hopefully so.

The settings that influence your lift will be:-

ELEVATOR_EFFECTIVENESS=

and

PITCH_STABILITY=

....... in most aircraft.cfgs, these will be set at 1.000 and you can increase or decrease the lift traits by adjusting these values.

I have at last found flight dynamics that I am happy with, by using the .air file from the Wilco / feelThere 737 PIC, with tweaked aircraft files from the Posky -700 and -800 models that I use in my sim.

I increased Elevator_effectiveness to 1.100

So try experimenting with these 2 settings above until you feel there is less sink when in the turns. I know Nic D has done this with the PMDG aircraft.cfg so perhaps he could share his settings.

David.

[sas550]

Tnx! I'll try that. BTW is the posky files tweaked by yourself? And from wich version of pic 737?

[David Rogers]

The only tweak to the POSKY aircraft.cfg is the one I mentioned above - slightly improving the ELEVATOR_EFFECTIVENESS to 1.100.

The Posky models are stunning, really beautiful exterior models but the .air files that come with the Posky models are really hopeless, so I wouldn't recommend using those.

In the aircraft.cfg that comes with Posky, the [Flight tuning] settings are crazy (the elevator is set at 0.351 !!!).

So to summarize what I did to get what I would describe as fantastic flight dynamics:-

- Download Posky models from www.projectopensky.com (http://www.projectopensky.com)
- Install into your FS2004 but delete PANEL folder (or remove everything but [VIEWS]. )
- Insert your own SOUND folder. (I use a fab freeware NG sound pack from AVSIM).
- Delete the posky .air file (starts with "OS") - they really are dreadful.
- Place an alternative airfile into the posky folder (I use B737-4A00A.air from 737-400PIC).
- Go to the posky aircraft.cfg file and change the [FLT SIM] entry that says SIM= to point to the new Wilco .air file... (ie. delete the "OS..." reference to the posky .air file and replace with reference to the new B737-4A00A.air file).
- Scroll down the aircraft.cfg file to [FLIGHT TUNING] and reset all values to 1.000

- Download and use the latest 737700.txt and 737800.txt files from PM for your PM CDU.... these made a huge difference to me, in terms of things like flap effect.

....oh and make sure general realism is set to fully realistic in FS settings!

you're done!

Sounds more complicated than it is.... :)

[sas550]

Tnx David! I'm now setting up the new model for some tests.

In this aircraft.cfg (Posky) it's the aileron_effectiveness that has =0.350 and the elevator_effectiveness=1.500

Still change elevator to 1.100?

[David Rogers]

Oh yes, you're right sorry, it was the AIELERON_EFFECTIVENESS that had the bizarre value of 0.351 !

You may want to try your ELEVATOR at 1.000 first as you may find this 'loosens' it enough...(I certainly wouldn't leave it at 1.500, this will be too reactive in flight).

I personally was aiming for the fluidity of the LDS 767 and DF 727 flight models while not turning the manouvrability into that of a C152! ..... so I like it at 1.100 but try 1.000 first.

The essence of the change is the feelthere 737PIC's .air file, which does not suffer the nasty 'pitch sink in turns' that the PMDG737 models have.

:)

[sas550]

Ok Tnx! I'm at work for a couple of weeks now so it won't be any flying but as soon as I get back home I'll try the new settings.