Hello, Michael!
Current CG position is already computed, you can see it in CDU at takeoff page. Also there is desired stab position for takeoff due to selected flaps.
I checked that, but this data are left empty on the takeoff screen. Maybe I have to press some "calculate" or "enter" button on CDU to get it. Honestly, since I prefer classic analog aircrafts I don't have experience with these computers and I am used to hand calculation and graphs.
So I could do something wrong.
BTW: Latest version I have (from git) has graphical bug - CDU keyboard and frame are white, seems the texture is not loaded.
Also, I didn't redo v-speeds calculation of first officer, but thay are slightly wrong.
What do you mean by redoing the V-speeds? Current (old) speeds are wrong because they don't reflect the values for real plane or you have to calculate new V-speeds which fit better to your FDM? Hope it is the first case.
Just one thought about the speeds. I didn't checked how it is implemented in JSBSim, but airspeed indicator shows indicated airspeed which differs from the true airspeed. the difference due to altitude is included in JSBSim I think, but I doubt there is also included aircraft type specific position error which should be coded manually. I am not sure there are calibration graphs in documents we have. But this data is included in POH quite often.
Moment from stabilizer is calculated correctly, elevator guessed.
I think so, that's why I meant the problem with rotation could be caused rather by wrong position of AERORP or main gear than wrong stab/elev moments. Because it seems to me the moment needed to rotate the plane on the ground is inadequately high compared to moments needed to control the plane in free air. But maybe the default load settings are outside the approved load envelope. I didn't check that.
Now I'm concentrated on engine thrust table, I want to match QRH climb and descent numbers.
I am crossing fingers to you. But I am afraid this could be very difficult to do with so few aerodynamic data we have. Performance is about lift drag and thrust. The more accurate these data is the more accurate simulation is with respect to the aircraft performance. As you can see in Tu-154 JSBSim or Boeing 777 aerodynamics documents, this data is dependent also on Mach number. Looking at the B737.xml the lift is based on one lift curve which is only modified by adding some constants due to flaps, spoilers, etc. Drag is based again on one curve modified by adding constants again, there is at least simple mach correction also provided by adding constants due to mach nr. On the other hand most of the flight is performed on rather small AOA for which these approximations could be acceptable.
BTW: You model lift with one curve and add some constant portion of lift for each flap stage. Basically you move the lift curve along the y-axis (in 2D plot) That is how flaps works. The problem is, for higher degrees of flaps, the leading edge slats are also automatically extended. Such lift curve is moved in y-direction towards to higher lift values due to flap effect but also has significantly extended "linear" part due to slat effect, so the maximal lift occurs at higher AOA's.
By the way, I fly with joystick and for me rotation seems ok.
I know, mouse is bad for control. That is the reason why I don't want to do any reviews of planes, since I think the simulation should be controlled with proper hardware - yoke/stick, pedals and throttle quadrant. On the other hand in this rotation problem I don't think there is so big difference in behavior between the mouse and stick. The problem is that to rotate the plane you have to strongly deflect the stick/ mouse back from the neutral position but immediately after rotation you must strongly deflect it forward from its neutral position to keep desired attitude. With mouse it is just moving the mouse, with stick you can feel the resistance of the spring in those movements. But the effect on the plane should be similar. Weird.
Just one unimportant bug to note: if I want to restart simulation by using menu, the simulation falls and you have to start it again.
Regards
Honza