.air file editing

[brettt777]

I have been playing around with some old freeware planes for my own personal fun. I have a thing about having the flight controls move accurately. I hate it when a simulator shows a plane having 30 degrees of up elevator to do a normal climb when I know that at a normal cruising airspeed, especially in a jet of some kind, it takes very little elevator or stabilator movement to induce said climb or turn. I know that many higher end jets have mechanisms in their flight controls that limit the amount of flight control movement for a given stick input depending on airspeed, attitude, etc. A good example of this is an Alphajet. They have such a device that prevents excessive stabilator movement above a certain airspeed so a student cannot easily over G the airframe. I have been trying with some success to simulate this effect.
I figured out how to do this in the .air file and while it works on some planes, it doesn't work on others. At least it doesn't work correctly. What I mean is... when it works, the stabilator movement is limited at higher speeds when the plane is airborne. Full stick movement causes only about 5, maybe 10 degrees of stabilator movement. But it has full movement when the plane is flying slow and dirty. An easy adjustment in the .air file can create this effect. But on some planes, when I make this adjustment, the stabilator still moves a full 25-30 degrees or whatever. Aerodynamically the plane flies correct, i.e. I pull the stick all the way back at higher airspeed and I may get a high G climb but it doesn't yank straight up and pull 15 G's. But the flight controls still move the same full throw. I am wondering why this works on some planes and not on others. What would cause the flight controls to move full throw regardless of how I adjust #517, 518, or 519 in the .air file?
As I said, I am experimenting with this on some older freeway planes for my own fun.

[Ivan]

I believe your issue isn't in the AIR file, it is more likely in the visual model. I know have had to correct some of the default settings for animations on some of the aircraft I have built. Generally to do some really fine tuning, I have had to go into SCASM, but since you are using a later simulator, you may need a different method.

Good Luck.
- Ivan.

[Milton Shupe]

Try looking at tables 400-433 which influence responses based on speed; the Mach tables.

Works sort of like a yaw damper.

[Dev One]

Hmmmm - might it depend upon the creating software? either FSDS or Gmax & its animation method? I use Gmax & find that one can restrict the visual & effect using 517, 518 & 519, but have not tried the mach related ones, mainly 'cos my models are of the slow variety.
Have you checked the Flight Tuning values in the .cfg to see if the offending kites are different too?
Keith

[Milton Shupe]

Just a reminder that the visual elevator is not keyframe animated but is FS controlled by the Airplane Geometry section statements:

elevator_up_limit = nn (Typically 30)
elevator_down_limit = nn (Typically 18-22)

The degrees of deflection are read and influence FS responses, the span of authority of which is dictated in the air file tables.

[brettt777]

I believe your issue isn't in the AIR file, it is more likely in the visual model. I know have had to correct some of the default settings for animations on some of the aircraft I have built. Generally to do some really fine tuning, I have had to go into SCASM, but since you are using a later simulator, you may need a different method.

Good Luck.
- Ivan.

What kind of program would I need, something that can open up the .mdl files? I have access to all kinds of CAD programs and I'm fairly knowledgeable on them. Is that what I would use?

[Milton Shupe]

Look, a simple test is to change the cfg file to limit elevator movement to 0 degrees deflection. Then see what happens to the visual model. Elevators are not animated in the modeling program; FS animates based on cfg entries. The in-flight responses OTOH are controlled by the air file and cfg entires.

[brettt777]

Look, a simple test is to change the cfg file to limit elevator movement to 0 degrees deflection. Then see what happens to the visual model. Elevators are not animated in the modeling program; FS animates based on cfg entries. The in-flight responses OTOH are controlled by the air file and cfg entires.

Okay that's what I thought. I have tried adjusting the elevator limits in the cfg file and again, it works on some planes but not on others. On those planes that it doesn't seem to work on, would there be something in the .air file that might work instead?

[Milton Shupe]

Okay that's what I thought. I have tried adjusting the elevator limits in the cfg file and again, it works on some planes but not on others. On those planes that it doesn't seem to work on, would there be something in the .air file that might work instead?

Are we talking about the visual elevator deflection?
If so, not to my knowledge. Visual response is strictly cfg controlled.
EDIT: But Mach tables will limit elevator deflection at high speeds due to tables 410, 420, 423, 433.

If you mean flight model response, the tables involved in the air file control elevator response and authority. But cfg setting can increase or decrease those responses based on deflection settings.

At higher speeds near mach1, there are mach tables that can diminish authority and visual model movement at higher speeds. EDIT: (tables 410, 420, 423, 433)

If you know some aircraft with similar high speed limits, you can experiment with copying the 410, 420, 423, 433 appropriate tables to your air file for testing. Copy to clipboard and Replace from clipboard.

EDIT: The air file mach tables that seem most accurate are the Boeing 747 and 777 tables.

[Dev One]

Just wondering if some of the models have had their controls Key Frame Animated as opposed to the simple Axis orientated ones. I know for example if one animates split flaps in Gmax with a simple axis orientation, one must deflect the flap through 90° in order to get say a 60° visual (& lift & Drag)
response as described in the aircraft.cfg.
Keith

[Milton Shupe]

I don't think so Keith. With flaps, you have 3-4 options for animating, both FS and KeyFrame.

Now, if you write your own XML code, then theoretically you could animate your elevator that way visually, but that would have no connection to the flight model without using l_elevator or r_elevator.