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Guest Lizardo

Flight Model Adjustments

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Hi Guys,I would like to make small adjustments to some of the default planes in fs9, but I have no idea what and where to tweak.I feel that when a plane is deflected from its longitudinal axis using rudder and then the rudder is removed, the plane springs back to the original longitudinal axis too violently and sometimes exhibits characteristics of an underdamped oscillation. Are there variables I can adjust to damp the action of the restoring force when the rudder input is removed? Where are the variables located? How much adjustment might be needed? I would also like to modify some of the default planes so that the nose wheel steering in a tricycle gear airplane is much less sensitive to rudder input, while retaining the responsiveness of the actual rudder control during flight and high speed taxi. In other words is it possible to control the amount of deflection caused by a given rudder pedal input separately for the rudder and the nose wheel? Where are the variables located? How much adjustment might be needed? Thanks for helping out a beginner,

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Open up the airplane's CFG file (saving the original)..and just mess around. Everything is a bit inter-related, and it just takes "playing" to find out how it works. (option #2: be an aeoronautical engineer and argue with how MS interprets.) :-)

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Haha, you have to have been there to really appreciate it. I don't know if you can call out the steering differently from the rudder or not...real planes will spring back though. You might look under "flight tuning" in the CFG and lower the rudder effectiveness. (mostly, the rudder is a "trim" to point the plane's nose. Just the nose, not the direction of the plane...as you will find out in strong cross-wind landings.)

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Does anyone know of a way to set nose wheel sensitivity independent of rudder sensitivity?

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Option #2 is only available to the elite minority of flight simmers with a solid background in engineering, aerodynamics, and perhaps flight simulation programming.However, anyone can be a critic, and most especially those who are familiar with how real aircraft behave in flight and on the ground.Michael,I can't recommend just playing around with the aircraft.cfg or airfile as Lizardo suggests, not when accurate information pertaining to the flight dynamics is available from people who have been reverse engineering the thing for years.If a little knowledge is a dangerous thing then NO knowledge is a sure recipe for disaster, or frustration at the very least.You should visit this site and take a look at the utilities and information available there:http://perso.wanadoo.fr/hsors/FS_Soft/In particular, for general info on the FS file structure Ron Freimuths' AirEd ini file and his "Comments on AC CFG" are most helpful, and the AirEd, and AAM utilities are indispensable for airfile editing along with AFSD for inflight data display while testing aircraft after changes have been made. >I feel that when a plane is deflected from its longitudinal axis using rudder and then the rudder is removed, the plane springs back to the original longitudinal axis too violently and sometimes exhibits characteristics of an underdamped oscillation. Are there variables I can adjust to damp the action of the restoring force when the rudder input is removed? Where are the variables located? How much adjustment might be needed?I would also like to modify some of the default planes so that the nose wheel steering in a tricycle gear airplane is much less sensitive to rudder input, while retaining the responsiveness of the actual rudder control during flight and high speed taxi. In other words is it possible to control the amount of deflection caused by a given rudder pedal input separately for the rudder and the nose wheel? Where are the variables located? How much adjustment might be needed?< I'm not entirely sure that I understand this question. But based on past problems that I've had with FS aircraft, I can say that if you are using a 3 axis controller or rudder pedals and nosewheel STEERING sensitivity is a problem then:For decreased steering sensitivity try lowering the entry for steering angle (entry #7 for point.0 shown below in bold text) found in the aircraft.cfg file under the (contact_points) section:(contact_points) //0 Class //1 Longitudinal Position (feet) //2 Lateral Position (feet) //3 Vertical Position (feet) //4 Impact Damage Threshold (Feet Per Minute) //5 Brake Map (0=None, 1=Left, 2=Right) //6 Wheel Radius (feet) //7 Steer Angle (degrees)<----Adjust this entry inpoint.0 found below. //8 Static Compression (feet) (0 if rigid) //9 Max/Static Compression Ratio //10 Damping Ratio (0=Undamped, 1=Critically Damped) //11 Extension Time (seconds) //12 Retraction Time (seconds) //13 Sound Type //14 Airspeed limit for retraction (KIAS) //15 Airspeed that gear gets damage at (KIAS)point.0=1, -16.80, 0.00, -3.35, 3200, 0, 0.40, 40.0, 0.30, 2.5, 0.90, 3.0, 3.0, 0, 0, 235point.1=1, 1.40, -3.91, -6.65, 2200, 1, 1.13, 0.0, 0.45, 2.5, 0.83, 4.5, 4.5, 2, 0, 235point.2=1, 1.40, 3.91, -6.65, 2200, 2, 1.13, 0.0, 0.45, 2.5, 0.83, 4.5, 4.5, 3, 0, 235point.3=2, 0.00,-20.00, -1.25, 1200, 0, 0.00, 0.0, 0.00, 0.0, 0.00, 0.0, 0.0, 5point.4=2, 0.00, 20.00, -1.25, 1200, 0, 0.00, 0.0, 0.00, 0.0, 0.00, 0.0, 0.0, 6point.5=2, -16.25, 0.00, -1.66, 2400, 0, 0.00, 0.0, 0.00, 0.0, 0.00, 0.0, 0.0, 9point.6=2, 2.41, 0.00, -2.08, 1200, 0, 0.00, 0.0, 0.00, 0.0, 0.00, 0.0, 0.0, 4static_cg_height = 5.85 //(feet) altitude of CG when at rest (altitude when loaded on ground)static_pitch = 10.69 //degrees (pitch when loaded on ground)Also, the longitudinal position of the nosegear affects steering. A position farther away from the C.G. will decrease the steering effectiveness, while moving the nosegear closer to the C.G. position will increase the steering effectiveness. This seems to affect the turning radius more than the nosewheel steering sensitivity though.So.... if I want to have the nosewheel steering be less sensitive on the takeoff and landing roll, I reduce the steering angle (entry #7 for point.0). If the aircraft can't turn tightly enough while taxiing at low speeds, then I move the nosegear position (shown below in bold text) closer to the C.G (aft):point.0=1, -16.80, 0.00, -3.35, 3200, 0, 0.40, 40.0, 0.30, 2.5, 0.90, 3.0, 3.0, 0, 0, 235Neither of these changes to the nosegear position (point.0) or the steering angle (entry #7) will affect the inflight yaw or rudder control charecteristics.

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Poking around without knowledge about what you are doing or at least the effect of the variable you are changing is for monkeys.Thank you very much. You answered my question well. I was hoping someone would have an intelligent answer, and you did.:)

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