Center of gravity trouble ?

Posted:
Tue Apr 06, 2004 3:47 pm
by Woodylepic
I realy dont enderstand what is wrong in this aircraft.cfg
Re: Center of gravity trouble ?

Posted:
Tue Apr 06, 2004 7:48 pm
by Milton
Woody,
Hard to say looking at just this info but one issue may be the crash point#8 is 9 feet behind the rear wheel and likely underground.
You should probably place the
Re: Center of gravity trouble ?

Posted:
Tue Apr 06, 2004 8:41 pm
by Woodylepic
//moteur loraine 12 ed
// poid a vide 390 kg
//480 ch a 2300 tr/mn
// cylindrer 25 litre (127 cubic inches)
// regime 1100 tr/mn economique, 2300 tr/mn decolage 1850 tr/mn normale
//compression 6
//consomation dessence (sans reducteur 103kg/heure
???Re: Center of gravity trouble ?

Posted:
Tue Apr 06, 2004 9:09 pm
by Woodylepic
[LIGHTS]
//Types: 1=beacon, 2=strobe, 3=navigation, 4=cockpit, 5=landing x,y,z
light.1=3, 0.46, -3.45, -6.75, fx_navred
light.2=3, 0.46, 3.45, -6.75, fx_navgre
light.3=3, -21.63, 0.0, -1.51, fx_navwhi
light.4=3, 0.00, 0.0, 6.00, fx_navwhi
light.5=3, -1.2, 0.00, 6.00, fx_navwhi
[Radios]
// Radio Type=availiable, standby frequency, has glide slope
Audio.1=1
Com.1=1, 0
Nav.1=0, 0, 0
Adf.1=1
Transponder.1=0
Marker.1=0
[keyboard_response]
//Breakpoint speeds (knots) on the keyboard increments of control surfaces.
//Speed at which the incremenet is reduced to 1/2 and 1/8 respectively.
elevator=200, 1000
aileron=200, 1000
rudder=200, 1000
[direction_indicators]
//1 Type: 0=None, 1=Vacuum Gyro, 2=Electric Gyro, 3=Electro-Mag Slaved Compass, 4=Slaved to another
//2 Indicator number of slaving indicator if Type=4
direction_indicator.0=1,0
direction_indicator.1=2,0
[attitude_indicators]
//Type: 0=None, 1=Vacuum Gyro, 2=Electric Gyro
attitude_indicator.0=0
[turn_indicators]
//Type: 0=None, 1=Electric Gyro, 2= Vacuum Gyro
turn_indicator.0=0
[EFFECTS]
wake=fx_wake
water=fx_spray
dirt=fx_tchdrt
concrete=fx_sparks
touchdown=fx_tchdwn_s, 1
startup=fx_engstrt_vega
windshield_rain_effect_available=0 //Do not draw rain on this windshield
[electrical]
max_battery_voltage=0
generator_alternator_voltage=12
max_generator_alternator_amps=35
autopilot=0, 5 , 17.0
light_nav=0, 5 , 17.0
light_panel=0, 5 , 17.0
[fuel]
Center1=-5.74, 0.00, .653, 354, 0.0 //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
Center2=-3.10, 0.00, .653, 354, 0.0 //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
Center3=-0.48, 0.00, .653, 354, 0.0 //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
fuel_type=1 //Fuel type: 1 = Aviationgas, 2 = JetA
number_of_tank_selectors=3
electric_pump=0
Re: Center of gravity trouble ?

Posted:
Tue Apr 06, 2004 10:14 pm
by SilverFox441
Your settings:
vtail_area=3.12 //Square feet
vtail_span=3.17 //Feet, tip to body
and
htail_area=4.38 //Square feet
htail_span=16.24 //Feet
Don't seem to make sense.
For the VTailnumbers to make sense the Vtail would have to have a chord of less than 1'! (actually about 11.8 inches) Judging from your image the real chord is in the area of 4-5 feet. This would give you an area of 12.5-15 square feet. This would make the plane more stable in yaw.
It looks like a similar area miscalculation may have been made in the horizontal numbers.
Should make the plane more flyable.
Re: Center of gravity trouble ?

Posted:
Tue Apr 06, 2004 10:49 pm
by Woodylepic
[airplane_geometry]
wing_area=775.81 //Square feet
wing_span=47.89 //Feet
wing_root_chord=8.10 //Feet
wing_dihedral=2.60 //Degrees
wing_incidence=2.10 //Degrees
wing_twist=0.0 //Degrees
oswald_efficiency_factor=0.6 //Measure of lift effeciency of wing
wing_winglets_flag=0 //Are winglets available?
wing_sweep=2.3 //Degrees, wing leading edge
wing_pos_apex_lon=2.02 //Feet, longitudinal distance from reference point, negative going aft
wing_pos_apex_vert=1.94 //Feet, vertical distance from reference point, positive going up
htail_area=77.38 //Square feet
htail_span=16.23 //Feet
htail_pos_lon=-19.17 //Feet, longitudinal distance from reference point, negative going aft
htail_pos_vert=-1.37 //Feet, vertical distance from reference point, positive going up
htail_incidence=0 //Degrees
htail_sweep=26.0 //Degrees, horizontal tail leading vtail_area = 18.0 //Square feet
vtail_area=38.76 //Square feet
vtail_span=6.22 //Feet, tip to body
vtail_sweep=25.0 //Degrees, vertical tail leading edge
vtail_pos_lon=-19.17 //Feet, longitudinal distance from reference point, negative going aft
vtail_pos_vert=2.62 //Feet, vertical distance from reference point, positive going up
elevator_area=38.00 //Square feet
aileron_area=20.51 //Square feet
rudder_area=17.66 //Square feet
elevator_up_limit=25.0 //Degrees
elevator_down_limit=25.0 //Degrees
aileron_up_limit=16.0 //Degrees
aileron_down_limit=16.0 //Degrees
rudder_limit=30.0 //Degrees
elevator_trim_limit=0.0 //Degrees
spoiler_limit=0.01 //Degrees
spoilerons_available=1 //Spoilerons Available?
aileron_to_spoileron_gain=0 //Aileron to spoileron gain
min_ailerons_for_spoilerons=0 //Degrees
min_flaps_for_spoilerons=0 //Minimum flap handle position when spoilerons activate
[Reference Speeds]
flaps_up_stall_speed=62.5 //Knots True (KTAS)
full_flaps_stall_speed=62.5 //Knots True (KTAS)
cruise_speed=89.09 //Knots True (KTAS)
max_indicated_speed=200 //Red line (KIAS)
[autopilot]
autopilot_available=1
flight_director_available=0
pitch_takeoff_ga=0.0
default_vertical_speed=700.000000
autothrottle_available=0
direction_indicator=1
max_pitch=10.000000
max_pitch_acceleration=1.000000
max_pitch_velocity_lo_alt=2.000000
max_pitch_velocity_hi_alt=1.500000
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=0.0
default_bank_mode=2 //Default to Heading Hold
[forcefeedback]
ground_bumps_magnitude1=2600 ; 0 - 10000
ground_bumps_angle1=8900 ; 0 - 35999 degrees
ground_bumps_intercept1=5.0
ground_bumps_slope1=0.6
ground_bumps_magnitude2=1200 ; 0 - 10000
ground_bumps_angle2=9100 ; 0 - 35999 degrees
ground_bumps_intercept2=0.085
ground_bumps_slope2=0.65
crash_magnitude1=10000 ; 0 - 10000
crash_direction1=01000 ; 0 - 35999 degrees
crash_magnitude2=10000 ; 0 - 10000
crash_direction2=9000 ; 0 - 35999 degrees
crash_period2=75000 ; in microseconds
crash_duration2=3500000 ; in microseconds
[stall_warning]
type=1
[exits]
number_of_exits=0
[brakes]
toe_brakes_scale=1.000000
parking_brake=1
[hydraulic_system]
normal_pressure=0.000000
in the fs2004 sdk he the formule for measuring the yaw is
MOI = EmptyWeight * (D^2 / K)
Pitch Roll Yaw
D = Length (feet) Wingspan (feet) 0.5* (Length+Wingspan)
K = 810 1870 770
MY LENGT= 31.89968 FEET
MY SPAN IS 47.88748 FEET
MY empty_weight_yaw_MOI IS 31.9878+47.89968=79.88748 FEET *.5=39.94374^2=1595.502365/770=2.072080994*4199.763=8702.249091
but your wright i have check some other aircraft file and the yaw MOI is the sum of the pitch and roll moi i will try hall ou said and give you info soon thank very much !
Re: Center of gravity trouble ?

Posted:
Wed Apr 07, 2004 12:01 am
by Milton
Woody,
The vtail numbers and rudder still look low to me.
Re: Center of gravity trouble ?

Posted:
Wed Apr 07, 2004 9:55 am
by Woodylepic
i have remake all my geometry to day check up there
pls tel me if you see some error
i have a question here
i have 2 wing so i must double my wing area that right ?
if yes i have set wing area at 775.81 ft ^2 (387.905ft^2 *2)
some plane in c.o.f seem to have only 1 wing the jenny have 1 wing area but the viker vimy is acurate whit 2 wing area ?
Re: Center of gravity trouble ?

Posted:
Fri Apr 09, 2004 9:15 pm
by Woodylepic
Have find the trouble the tail below ground was my center of gravity at 0.0 to ahead and my laterale instability was the fault of my .air file i have made some change in my air file my plane is now flyable thank very much for your help.