Simviation Forums

This is a model by Mike Stone and was posted Nov 5, 2013 03:56 by Philippe Wallaert. It looks great but it doesn't seem to want to turn in the air. When I checked the fuel and payload before flight the fuel seemed normal but the payload was one single entry of 800lbs. The center of mass in the diagram to the right shows to be way forward of the wing but on the centerline. There is no way with the supplied aircraft.cfg file to redistribute the weight. I tried using the weight distribution section of the config file for the Gulfstream III but it didn't really have any positive impact. Any suggestions?

What you could do is to modify the aircraft.cfg file this way to modify the CG:

[WEIGHT_AND_BALANCE]
max_gross_weight = 35800.000
empty_weight = 20735.000
reference_datum_position = 0.000, 0.000, 0.000
empty_weight_CG_position = -1.700, 0.000, 0.000 // this line <<<<<<<

DO NOT INCREASE THIS VALUE MORE THAN -2.500 BECAUSE YOU WILL GET A CRASH!

Please note that with my Falcon 2000, I have no problems? The aircraft turns correctly with or without autopilot on.

Regards

Phil

Maybe it's just me but the Falcon 2000 seems very sluggish making turns compared to the other jets of it's size. And if the schematic is correct and the model's center of mass is that far forward I would think it could affect the handling.

I agree with you, the aircraft reacts more like a A380 than a business jet!
I think the problem is related to moving surfaces. I will test some modifications and send you the results.
Have a nice day

Phili

Hi,

I modified the aircraft.cfg file this way and results are better:


[flight_tuning]
cruise_lift_scalar =1.000
parasite_drag_scalar =1.000
induced_drag_scalar =1.000
elevator_effectiveness =1.000
aileron_effectiveness =3.000 //2.002 <<---------- this line
rudder_effectiveness =1.000
pitch_stability =1.000
roll_stability =1.000
yaw_stability =1.000
elevator_trim_effectiveness =1.000
aileron_trim_effectiveness =1.000
rudder_trim_effectiveness =1.000

Cheers

Phil

Thanks, that improved the banking response tremendously. Something else I'm curious about is the acceleration rate of several of these modern jets. They seem to be able to hit 300 kts. shortly after leaving the ground and I have to cut the power back to just above idle to keep the overspeed warning from sounding.

Try looking in the Aircraft.cfg file for a section thus:

[TurbineEngineData]
fuel_flow_gain =0.004500
inlet_area =18.289500
rated_N2_rpm =29920.000000
static_thrust =21890.000000
afterburner_available =6
AfterBurnThrustSpecificFuelConsumption = 1.35
afterburner_throttle_threshold = 0.76
reverser_available =0
ThrustSpecificFuelConsumption = 0.6


Note the entry in RED above. Try incresing it a single digit at a time. The LARGER the inlet area, the slower the plane, top end and acceleration. You can also look on the net and verify the STATIC THRUST entry to be correct, or perhaps decrease it slightly and see how that affects the acceleration, balancing it against the INLET AREA entry for top end.
Best way to test top end, btw, is to set the weather in the sim to a "standard day" (readily available on the net), go to normal cruise altitude with no payload and about 50% fuel, full throttle, and let it accelerate to whatever it will. Note the result and adjust the appropriate entries as needed

Hope all this helps a little bit

Pat☺

Just for the record, I downloaded and installed the Falcon 2000 . For me it has flown and handled just as I expected it to, which means excellently. I hope you get yours perfected as well, good luck.