.air file & aircraft.cfg file parameter overlap question

[b3burner]

Hi, and my question is this:

If there's a situation where both the above mentioned files appear to be controlling a similar parameter, and I edit one file to max out that parameter, while I edit the other file to minimize that parameter (so they're basically at tug-of-war with each other)... which file generally will win out... in terms of how the plane might fly, feel, handle, behave, etc?

The aircraft.cfg file? Or the xxxx.air file?

If you want a specific example to see where I'm going with this question, let's use braking power while the plane is on the ground:

In the aircraft.cfg file, that parameter appears to be mainly controlled by the "toe_brakes_scale=" line. The higher the number, the stronger the braking on the wheels (I will presume from brief experimentation with it).

In the xxxx.air file, that condition appears to be controlled by the [Line 1101]- Flight Dynamics, submenu 10th line down "Braking Strength=" line.

As I bring one value up and the other one down, I simply want to know which file will win out in terms of control of the plane?

Since there appears to be some overlap between .air files and aircraft.cfg files, and they are not exclusively independent from each other in what they control, where exactly is the balance between them when you pit one file's variable against the other in opposite directions?

-- John

[old_wombat]

Can't generalise, but from my experience with landing the IRIS F-14A on the aircraft carrier, the answer seemed to be that the value of this particular parameter as actually used was the product, as in the maths sense, of xxx.air value times aircraft.cfg value. Now I'm going to go out on a limb and suggest that all of the aircraft.cfg values that are "scales" (as in, have the word "scale" in the parameter name) are going to be similar.

Steve from Mudgee

[jgf]

Data in the aircraft.cfg has precedence over data in the air file. If there are conflicts, FS9 will edit the cfg on its own for compatibility. But there are many parameters in the air file which have no counterparts in the cfg file.

For example, if your airplane has an AP you can delete the entire autopilot section of the cfg file, fly the plane, and FS9 will write default autopilot data back to the cfg file (there is a conflict since there is an AP gauge and FS9 expects certain data from it). OTOH, if your airfile specifies a jet engine and you change the cfg file to specify a piston engine, then you have a piston engine and any jet parameters in the air file are ignored (no conflict other than incorrect gauges). In the case of brake strength, it's even simpler; if the airfile says the brakes have a strength of x and you edit the cfg to give them a strength of 2x, FS9 merely uses the cfg value.

The Aircraft Airfile Manager program has much more detailed information than AirEd; even if you don't use the program, its ini file is 120k of descriptions of the airfile sections.

[napamule2]

John,
That is a very acute observation about cfg and air file entry concerning braking. You have good possiblities of being a cfg/air files guru if you spend some time at it.

In the air file there is a SDK 'guide'. Guide because with trial & error you will find that what is DECLARED in SDK can be circumvented with use of 'un-ortadox' values in the cfg. The same can be said as far as the air file entries go. Match? Mostly never. Tweak at will.

The cfg can have toe braking=1.000 . And the air can have strength= 12600. Your braking will be WEAK. With a Cessna that doesn't present a problem. But with a 747 you will feel how weak the brakes are (if you have any experience with a 747). Change the air entry to
'-32767' (the MAX value permissable) and you should have MUCH stronger brakes on the 747. And if you are aware of it, it CAN be used with Cessna and use of TAP of brakes.

Some modelers set the brakes to be weak in order to prevent tip over onto nose when you use hard braking on landing of certain tail draggers, etc. The value in the air file will allow this even if braking=1.000 in cfg. (But the real cure is to set the CofG to =-1.000 for
the longitudial value-shhhh-it's not in the SDK or in the Air ini-mum's the word.)

Anything over and above normal braking is taken care of by use of a SUPER SPOILER. It can REALLY stop you on a dime. Why would you need it? Well in my case I need it to slow vehicles down from 250 kts to 50 kts so I can manage a curve in the road. No need to mess with the braking any longer. The spoiler in cfg is in (Airplane_Geometry) section and SHOULD be set to = 59.989 and then you will set how STRONG the DRAG will be in the air file. Set spoiler drag anywhere from '400.000000' (medium) to '-1.000000'. If you make drag= to (minus) '-3.000000' you will do a (unreal) dead stop (boom!!) - stop on a dime. (That is how some jolly simmers are able to land a 747 on a carrier- they use this spoiler trick).

And you also have flaps DRAG. That can be a lot of fun to work with and can be used as a substitue for down shifting gears (for race car performance). Takes tweaking flaps section in cfg and play with flaps DRAG in air file. That can range from 400 to 1000 although you
might find a value such as 3000 as being a good starting point for use as gear shifting.

I could go on, but you get the idea. There is a LOT of things that they don't tell you about what can be done (normal settings) and what you can tweak for (max performance). You have to find, figure out, get familiar with trial-n-error use, and then use what you need. They don't want you to tip over on your nose, or over run the end of runway. But they will not tell you how to 'fix' it. You have to learn all that on your own. Or live in ignorant bliss.
Chuck B
Napamule

[b3burner]

Napa Mule,

Thank you for the compliment on my insight, and for your insights as well.

I do want to clarify one point though. In your examples of air file settings you refer to the number "negative 32,767" as a maximum value for brake strength. Would that not have been a positive number? I would have thought negative = weaker, positive values = stronger?

Are all air file values set so that negative numbers are increasing the magnitude of the parameter more than their positive counter-parts? Or am I misunderstanding your post?

Thanks,

-- John

[jgf]

positive and negative values are consistent regarding physical coordinates; but within the airfile there seems little consistency even between similar aircraft

data for section 1101 is:
13=26,int16_2,Braking Strength - Max (ft/sec^2 ?)
13h=Rolling coefficient of friction. Defaults to -16.00, max effort Flag|Otherwise 0 to 15.9995|More realistic values are 6.0-15.0|Max rate occurs only after full weight on tires
;13=26,int16,Braking Strength - Max (ft/sec^2 * 2048?)
;13h=Defaults to -32768, max effort Flag|Otherwise 0 to 32767, More realistic values are 10,000-30,000|Max rate occurs only after full weight on tires
; 32767 is about 16 ft/sec^2:-0.5 G|May relate to Tire Coeff of Friction

[napamule2]

John,
No, I did mean MINUS value. It's physics, some math, and plain ole 'horse sense' derived from experience with default aircraft's cfg & air file entries. But that was 15 years ago. So there is a learning curve. Instead of 'time and effort' maybe I should say 'trial & error' in order to get 'best results'. It's all in your hands. You are the engineer. You decide (ie: what is best for YOUR specs and controllers-mine might
be different). So there ARE a lot of interaction/relationships that must be taken into cosideration. See the two extremes in pic. If you are delighted by what you see (or can derive/understand/use from what is provided by MS) then you have a very good chance of someday hating doing dynamics edits as much as I do. Happy tuning!
Chuck B

[b3burner]

Okay, I think I was originally referring to "braking strength", which I see is a positive 5-digit integer.

Interesting that if I open up Section 1101 and look at braking strength in airEd, it's a 5-digit integer. But if I look at the same parameter in Aircraft Airfile Manager, it's a 1 or 2 digit number with decimals... measured in ft/sec ^squared.

So between different apps for the same file I can't even trust the values to remain the same. I can now see how involved and difficult this can become. Now I know why some simmers just download the files as is and have a "set it and forget it" attitude. Because it'll drive you nutz if you let it!

[b3burner]

Napa Mule,

Sorry, missed the 2nd entry in your text section. Yes indeed, you're right... the B747 does have a negative number for 'braking strength'. I'm thinking it might be some odd result of multiplication where if it's factored with a negative value, the result becomes negative? It's not so much a linear spectrum from a 5-digit negative number on one end, to a 5-digit positive number on the other; as it is you take a +number and multiply it by - the result is going to be negative. Interesting contrasts, and as you say, a lot to learn about working with those sorts of things.

[tgibson_new]

As I understand it, the toe brake scalar value in the cfg file overrides the braking strength value in the air file, as well as those weight values as well. This is all AFAIK, though.

Hope this helps,