Flight Dynamics

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UKVoodoo

Charter Member
Hi

I'm having a problem with some flight dynamics that when pulling high G's in a turn my aircraft sits in a 20 degree angle knife edge as it performs the turn, it doesn't drop or gain height in the turn it just sits in a knife edge all the way round :kilroy:

Is there anything in the aircraft.cfg that I can edit that can keep it at 0 degree so it doesn't side slip in the turn

[flight_tuning]
cruise_lift_scalar=1.000
pitch_stability=1.000
roll_stability=1.000
yaw_stability=1.000
parasite_drag_scalar=2.000
induced_drag_scalar=1.000
elevator_effectiveness=2.000
aileron_effectiveness=1.000
rudder_effectiveness=1.000
elevator_trim_effectiveness=1.000
aileron_trim_effectiveness=1.000
rudder_trim_effectiveness=1.000

That's the flight tuning in the cfg

Thanks
Matt
 
UKVoodoo said:
Hi

I'm having a problem with some flight dynamics that when pulling high G's in a turn my aircraft sits in a 20 degree angle knife edge as it performs the turn, it doesn't drop or gain height in the turn it just sits in a knife edge all the way round :kilroy:

Is there anything in the aircraft.cfg that I can edit that can keep it at 0 degree so it doesn't side slip in the turn

[flight_tuning]
cruise_lift_scalar=1.000
pitch_stability=1.000
roll_stability=1.000
yaw_stability=1.000
parasite_drag_scalar=2.000
induced_drag_scalar=1.000
elevator_effectiveness=2.000
aileron_effectiveness=1.000
rudder_effectiveness=1.000
elevator_trim_effectiveness=1.000
aileron_trim_effectiveness=1.000
rudder_trim_effectiveness=1.000

That's the flight tuning in the cfg

Thanks
Matt
Click to expand...


Flight_tuning is not sufficient to analyze the problem, even if the values parasite_drag_scalar and elevator_effectiveness=2.000 are maybe too big... The entire flight dynamics is needed to solve the problem...
 
I don't quite understand what is happening with the aircraft from your description. What is the aircraft by the way?
 
Its the Alphasim Viggen

FS92012-02-2116-56-09-01.jpg


As you can see rather then been level in the turn (like the contrails show it should be) the aircraft is 20 degrees nose up in a knife edge as I'm making the turn

Below is everything in the cfg apart from the flightsim.x entries


[General]
editable=1
performance=Model: C Edwards\nPanel: P Perrott\nTextures: C Edwards \ Jens-Ole Koelberg\nFlight Model: J. McDaniel\n\nLength: 53 ft 9.25 in\nSpan: 34 ft 9.25 in\nWing area: 495.16 sq ft\nWeight: empty: 26,896 lbs\s maximum: 49,604 lbs.\nPower: (1) Volvo Flygmoter turbofan, 16,200 lbs thrust, 28,110 lbs. with afterburning\nRange: 1,250 miles\nMax Speed, altitude: Mach 2.0 @ 36,000 ft\nMax Speed, sea level: Mach 1.2\nService Ceiling: 60,000 ft.\nArmament: (1) 30 mm Oerlikon cannon, up to 13,228 lbs. of disposable stores.
atc_type=SAAB AIRCRAFT
atc_model=


[Views]
eyepoint=16.8, 0.0, 1.75 //(feet) longitudinal, lateral, vertical distance from reference datum

[weight_and_balance]

// ACM V2.3
max_gross_weight = 49604
empty_weight = 26896
reference_datum_position = 0, 0, 0
empty_weight_CG_position = 0, 0, 0
empty_weight_pitch_MOI = 130981
empty_weight_roll_MOI = 65720
empty_weight_yaw_MOI = 110426
empty_weight_coupled_MOI = 0
max_number_of_stations = 1

station_load.0 = 0.000000,0.000000,0.000000,0.000000


[lights]

//Types: 1=beacon, 2=strobe, 3=navigation, 4=cockpit, 5=landing

light.0 = 4, 18.75, 0.0, 1.00, fx_vclight,
light.2 = 2, -16.5,-14.9, -1.50, fx_contrail_Alpha Viggen
light.3 = 2, -16.5, 14.9, -1.50, fx_contrail_Alpha Viggen
light.4 = 2, 5.1, 7.82, 0, fx_contrail_Alpha Viggen
light.5 = 2, 5.1, -7.82, 0, fx_contrail_Alpha Viggen
light.6 = 3, -14.00, 0.00, 0.0, fx_engine_Alpha Viggen
light.7 = 5, -14, 0, 0, fx_coral_f15ab-blue
light.8 = 5, -13.92, 0, 0, fx_coral_f15ab-or

[GeneralEngineData]

//0=Piston, 1=Jet, 2=None, 3=Helo-Turbine, 4=Rocket, 5=Turboprop
engine_type = 1
fuel_flow_scalar = 1.000
engine.0 = -14.000, 0.000, 0.000

[smokesystem]
smoke.0 = 0, -17.84, 0, fx_coral_f15exhaust


[fuel]

//Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)

fuel_type = 2
number_of_tank_selectors = 1

LeftMain = 0, -1.5, 0, 750, 5
RightMain = 0, 1.5, 0, 750, 5
electric_pump=0


[contact_points]
static_pitch = 0
static_cg_height = 7.335
tailwheel_lock = 0
max_number_of_points = 7

point.0 = 1.000, 16.919, 0.000, -7.500, 3000.000, 0.000, 0.685, 30.000, 0.400, 2.500, 0.800, 5.000, 5.000, 0.000, 0.000, 0.000
point.1 = 1.000, -2.917, -6.650, -7.333, 4000.000, 1.000, 1.000, 0.000, 0.282, 2.500, 0.800, 5.000, 5.000, 2.000, 0.000, 0.000
point.2 = 1.000, -2.917, 6.650, -7.333, 4000.000, 2.000, 1.000, 0.000, 0.282, 2.500, 0.800, 5.000, 5.000, 3.000, 0.000, 0.000
point.3 = 2.000, -15.748, -14.989, -1.333, 1574.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 5.000, 0.000, 0.000
point.4 = 2.000, -15.840, 14.989, -1.333, 1574.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 6.000, 0.000, 0.000
point.5 = 2.000, -19.917, 0.000, -2.000, 1574.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 9.000, 0.000, 0.000
point.6 = 2.000, 27.288, 0.000, -2.525, 1574.803, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 4.000, 0.000, 0.000
gear_system_type=1


[keyboard_response]
elevator = 150.000000, 250.000000
aileron = 150.000000, 250.000000
rudder = 150.000000, 250.000000


[forcefeedback]
gear_bump_nose_magnitude = 1000
gear_bump_nose_direction = 18000
gear_bump_nose_duration = 250000
gear_bump_left_magnitude = 2000
gear_bump_left_direction = 35500
gear_bump_left_duration = 250000
gear_bump_right_magnitude = 2000
gear_bump_right_direction = 500
gear_bump_right_duration = 250000
ground_bumps_magnitude1 = 1250
ground_bumps_angle1 = 8900
ground_bumps_intercept1 = 5
ground_bumps_slope1 = 0.48
ground_bumps_magnitude2 = 450
ground_bumps_angle2 = 9100
ground_bumps_intercept2 = 0.075
ground_bumps_slope2 = 1
crash_magnitude1 = 2000
crash_direction1 = 1000
crash_magnitude2 = 2000
crash_direction2 = 9000
crash_period2 = 7500
crash_duration2 = 2500000
stick_shaker_magnitude = 2000
stick_shaker_direction = 0
stick_shaker_period = 111111

[airplane_geometry]
//ACM_AREAW1// 0,0,0,6.7939,0.5891,0.5891,0.8413,7.2956,1.1782,1.1782
//ACM_AREAW2// 1.6826,7.7972,1.7673,1.7673,2.5240,8.2989,2.3564,2.3564,3.3653,8.8005
//ACM_AREAW3// 2.9455,2.9455,4.2066,9.3021,3.5346,3.5346,5.0480,9.8038,4.1237,4.1237
//ACM_AREAW4// 5.8893,10.3054,4.7128,4.7128,6.7306,10.8070,5.3019,5.3019,7.5720,11.3087
//ACM_AREAH1// 0,0,0,1.6936,0.2822,0.2822,0.4031,2.0121,0.5645,0.5645
//ACM_AREAH2// 0.8062,2.3305,0.8468,0.8468,1.2094,2.6490,1.1291,1.1291,1.6125,2.9674
//ACM_AREAH3// 1.4113,1.4113,2.0156,3.2859,1.6936,1.6936,2.4188,3.6043,1.9759,1.9759
//ACM_AREAH4// 2.8219,3.9228,2.2582,2.2582,3.2250,4.2412,2.5405,2.5405,3.6282,4.5597
//ACM_AREAV1// 0,0,0,2.0878,0.2319,0.2319,0.3313,2.2521,0.4639,0.4639
//ACM_AREAV2// 0.6626,2.4164,0.6959,0.6959,0.9939,2.5807,0.9279,0.9279,1.3252,2.7450
//ACM_AREAV3// 1.1599,1.1599,1.6565,2.9092,1.3919,1.3919,1.9878,3.0735,1.6239,1.6239
//ACM_AREAV4// 2.3191,3.2378,1.8558,1.8558,2.6504,3.4021,2.0878,2.0878,2.9818,3.5664
//ACM_CAREAW1// 2.6509,2.6509,7.1830,8.5418,2.9455,2.9455,7.6036,8.8945,3.2401,3.2401
//ACM_CAREAW2// 8.0243,9.2472,3.5346,3.5346,8.4450,9.5999,3.8292,3.8292,8.8656,9.9527
//ACM_CAREAW3// 4.1237,4.1237,9.2863,10.3054,4.4183,4.4183,9.7070,10.6581,4.7128,4.7128
//ACM_CAREAW4// 10.1276,11.0109,5.0074,5.0074,10.5483,11.3636,5.3019,5.3019,10.9690,11.7163
//ACM_CAREAH1// 0,0,0.8468,1.6936,0.2822,0.2822,1.2499,2.0544,0.5645,0.5645
//ACM_CAREAH2// 1.6531,2.4152,0.8468,0.8468,2.0562,2.7760,1.1291,1.1291,2.4593,3.1368
//ACM_CAREAH3// 1.4113,1.4113,2.8625,3.4976,1.6936,1.6936,3.2656,3.8584,1.9759,1.9759
//ACM_CAREAH4// 3.6687,4.2192,2.2582,2.2582,4.0719,4.5800,2.5405,2.5405,4.4750,4.9408
//ACM_CAREAV1// 0,0,0.5219,1.5659,0.2319,0.2319,0.8532,1.8137,0.4639,0.4639
//ACM_CAREAV2// 1.1845,2.0615,0.6959,0.6959,1.5159,2.3092,0.9279,0.9279,1.8472,2.5570
//ACM_CAREAV3// 1.1599,1.1599,2.1785,2.8048,1.3919,1.3919,2.5098,3.0526,1.6239,1.6239
//ACM_CAREAV4// 2.8411,3.3004,1.8558,1.8558,3.1724,3.5482,2.0878,2.0878,3.5037,3.7960
wing_area = 495.160
wing_span = 34.790
wing_root_chord = 22.290
wing_dihedral = 3.000
wing_incidence = 0.000
wing_twist = 0.000
oswald_efficiency_factor = 0.890
wing_winglets_flag = 0
wing_sweep = 55.000
wing_pos_apex_lon = 14.012
wing_pos_apex_vert = 0.000
htail_area = 71.000
htail_span = 16.670
htail_pos_lon = -20.760
htail_pos_vert = 0.000
htail_incidence = 0.000
htail_sweep = 55.000
vtail_area = 30.000
vtail_span = 6.850
vtail_sweep = 55.000
vtail_pos_lon = -5.110
vtail_pos_vert = 3.060
elevator_area = 30.000
aileron_area = 50.000
rudder_area = 15.000
elevator_up_limit = 24.000
elevator_down_limit = 20.000
aileron_up_limit = 15.000
aileron_down_limit = 15.000
rudder_limit = 22.000
elevator_trim_limit = 18.000
spoiler_limit = 60.000
aileron_to_spoileron_gain = 0.000
min_ailerons_for_spoilerons = 0.000
min_flaps_for_spoilerons = 0.000
spoilerons_available = 0

[electrical]
max_battery_voltage = 24
generator_alternator_voltage = 28
max_generator_alternator_amps = 300
electric_always_available = 1

[TurbineEngineData]
fuel_flow_gain=0.002
inlet_area=6.500
rated_N2_rpm=29920.000
static_thrust=16200.000
afterburner_available=1
reverser_available=1.000

[Reference Speeds]
flaps_up_stall_speed=126.000
full_flaps_stall_speed=97.000
cruise_speed=800.000
max_indicated_speed=1200
max_mach=2.1

[autopilot]
autopilot_available=1
flight_director_available=1
default_vertical_speed=2000.000000
autothrottle_available=1
autothrottle_arming_required=0
autothrottle_takeoff_ga=0
autothrottle_max_rpm=90.000000
pitch_takeoff_ga=8.000000
max_pitch=15.000000
max_pitch_acceleration=2
max_pitch_velocity_lo_alt=2.0
max_pitch_velocity_hi_alt=1.5
max_pitch_velocity_lo_alt_breakpoint=20000.000000
max_pitch_velocity_hi_alt_breakpoint=28000.000000
max_bank=25.000000
max_bank_acceleration=1.800000
max_bank_velocity=3.000000
max_throttle_rate=0.100000
nav_proportional_control=9.000000
nav_integrator_control=0.250000
nav_derivative_control=0.000000
nav_integrator_boundary=2.500000
nav_derivative_boundary=0.000000
gs_proportional_control=9.520000
gs_integrator_control=0.260000
gs_derivative_control=0.000000
gs_integrator_boundary=0.700000
gs_derivative_boundary=0.000000
yaw_damper_gain=0.000000

[direction_indicators]
direction_indicator.0=3,0

[brakes]
toe_brakes_scale=1
parking_brake=1
[gear_warning_system]
gear_warning_available=1
pct_throttle_limit=0.000000
flap_limit_power=0.000000
flap_limit_idle=0.000000
[hydraulic_system]
normal_pressure=3000.000000
engine_map= 1, 0, 0, 0
[stall_warning]
type=1
[attitude_indicators]
attitude_indicator.0=1
[turn_indicators]
turn_indicator.0=1,0

[jet_engine]
thrust_scalar=0.700

[flight_tuning]
cruise_lift_scalar=1.000
pitch_stability=1.000
roll_stability=1.000
yaw_stability=1.000
parasite_drag_scalar=2.000
induced_drag_scalar=1.000
elevator_effectiveness=2.000
aileron_effectiveness=1.000
rudder_effectiveness=1.000
elevator_trim_effectiveness=1.000
aileron_trim_effectiveness=1.000
rudder_trim_effectiveness=1.000

[Flaps.0]
type= 1
span-outboard= 0.500
extending-time= 5.000
system_type= 1
damaging-speed= 325.000
blowout-speed= 400.000
lift_scalar= 0.001
drag_scalar= 3.000
pitch_scalar= 1.000
flaps-position.0= 0.000, 0.000
flaps-position.1= 10.000, 0.000
flaps-position.2= 20.000, 0.000
flaps-position.3= 30.000, 0.000
flaps-position.4= 45.000, 0.000

[Radios]
// Radio Type = availiable, standby frequency, has glide slope
Audio.1=1
Com.1=1
Com.2=1
Nav.1=1,0,1
Nav.2=1
Adf.1=1
Transponder.1=1
Marker.1=1
 
A link to the aircraft in question would be helpful, since there's data in the .air file that's not in the aircraft.cfg file.
 
As stated in above its the Alphasim Viggen so I cant provide links as its a payware aircraft, it doesnt matter ill write it off as a bad job and find another aircraft
 
I'd say that sounds normal to me, i remember seeing one perform at an Mildenhall air fete (oh happy memorys ) doing just that.
cheers ian
 
Oh right that's okay then, just seemed weird it knife-edging all the way through the turn while not gaining or losing height...thanks for the help all :salute:
 
Hair Ball?

UKV,
Here are my recommendations for changes to aircraft.cfg geometry section. I suspect the air needs tweaking as well.
Viggen: 'bogus' attitude on turns:
------------------------------------------------
wing_sweep = 55.000 change to = 0.000
oswald_efficiency_factor = 0.890 change to = 0.680
wing_pos_apex_lon = 14.012 change to = 4.012
htail_area=34.000 change to = 24.000
htail_sweep = 55.000 change to = 0.000
htail_pos_lon = -20.760 change to = -13.000
vtail_sweep = 55.000 change to = 0.000
vtail_pos_lon = -5.110 change to = -15.000

All the above (default) values are PATHETIC. They are not spec or 'real' (B-737 maybe?). Change to values indicated. Try it. The air file (flight_dynamics) section most likely needs to be scrutinized/ammended as well. 'Creative' dynamics are not preatty, or cute, or cuddly, or worth a dime. Good luck with this.
Chuck B
Napamule
 
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