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Staffan

Two simple questions.

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Hi,I am trying hard to give FS9 a chance to stay on my harddrive. Therefore I have two simple questions regarding AIR file tweaking.1. How can I adjust the pitch angle on the aircraft? In FS2002 there are wing_incidence & wing_twist to play with, but those entries does nothing in FS9. So where can I adjust it in FS9?2. Where do I adjust the increase or decrease drag in the Aircraft.cfg or AIR file in FS9?Looking forward to any constructive help. ;-)Fly safe,Staffan AhlbergSweden/Stockholm/ESSA

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>I really can not find out from all those posts, in simple words, how I can change the pitch and drag.< Staffan,You can edit Table 404 in the airfile to change fuselage pitch angle.As simply as I can express it, you should change the X values (wing angle of attack or AOA) in the main lift region of this table until you have what you want. The attached image shows Table 404 and identifies the wing AOA points from 0 - 17.5 degrees. Note that the X values are in radians (remember trigonometry?), and conversion is necessary if you want to make sense of this table. 1 radian=57.2959 degrees and 1 degree=0.017453 radian. For the purpose of editing table 404 1 radian=57.0 degrees and 1 degree=0.0175 radian is close enough.By shifting the points corresponding to the wing AOA from 0 degrees to about 10-14 degrees left or right along the lift slope you will be able to compensate for the loss of wing AOI and twist in FS9 as far as fuselage pitch angle is concerned. Shifting these points to the left will reduce the coefficient of lift at that AOA and result in a nose up pitch angle, and shifting them to the right will have the opposite effect.Suppose you want to compensate for the loss of a wing AOI of 2 degrees. You would first convert degrees to radians by multiplying 0.0175 x 2, which results in 0.035 radians. This is the amount to be subtracted from the X values in Table 404 that correspond to a wing AOA from 0 to approximately 10-14 degrees AOA.If you have AirEd, the X values can be edited by opening Table 404, pressing X on the keyboard, and noting the value of the wing AOA in radians in the box that appears. You then subtract 0.035 from this value to obtain the value that you want, type this new wing AOA value into the box, and then press enter on the keyboard to add this change to the airfile. This will shift that point to the left on the lift slope by 2 degrees. Repeat this process for the other points up to about 10-14 degrees (usually only two, but sometimes more depending on the utility used to create Table 404).If you read the long topic in the MSFS panel and design forum related to this problem, you will recognize that substituting AOA rotation for AOI rotation in FS9 will introduce induced drag errors into the flight model. I won't go into that here, you will just have to work with what is available in FS9 and if you want to change the fuselage pitch in the airfile then this is it.The aircraft.cfg file offers something called a cruise_lift_scalar in the (Flight_Tuning) section that can be used to adjust cruise pitch. Ron Freimuth in "Comments on aircraft.cfg" states that this will also affect the "location of Induced Drag parabola". If you adjust your flight model with this scalar (or after making any other changes), I recommend using Herve Sors AFSD to get a look at the results of your tweaking. It will show you what has happened to the induced drag or lift coefficients when you change this scalar.As far as setting the drags are concerned, there are many variables to consider in both the airfile and aircraft .cfg files. Induced drag will of course be affected by editing Table 404 in the manner I suggested above, as it is directly proportional to the creation of lift. Parasite drag can still be adjusted in the airfile Rec 1101 Cdo Drag Coefficient-Zero Lift, and the drag for the flaps, landing gear and spoiler can be set in Rec 1101 also.The aircraft .cfg file has a parasite_drag_scalar in the (flight_Tuning) section that is analogous to the Cdo airfile entry, and the induced_drag_scalar that might be used to adjust (or correct) the induced drag.In the (Flight_Tuning) section, wing_area, and possibly wing_span will also affect induced drag, and should be set to the real aircraft values, and oswald_efficiency_factor is also important for induced drag. The wing_winglets_flag will reduce induced drag if set to 1. "Comments on aircraft.cfg" provides a wealth of information, most of which still applies to FS9. It can be found here:http://perso.wanadoo.fr/hsors/FS_Soft/along with almost all of the flight dynamics utilities (AirEd, AFSD, AAM etc.) necessary for editing the MSFS flight models, and some great sources of information about flight dynamics.

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