Update! MSFS2020 - TBM 930 Improvement Mod - V.1.13.16.1


Flight model modification version V.1.13.16.1

The book "Quest for Performance: The Evolution of Modern Aircraft" has no data about the TBM930. Therefore I use the Cessna 310 II data. The zero-lift drag coefficient CD,0 is 0.0267 and maximum lift-drag ratio (L/D)max is 13.0. The Asobo zero-lift drag coefficient CD,0 is 0.0255 and the measured maximum lift-drag ratio (L/D)max is 14.2, measured with the MSFS 2020 build-in DevMode tool Aircraft Editor, Debug, Sim Polar VhVs. The (L/D)max values differ and I think this is one reason for the "floating above the runway at landing" complains about Asobo flight models. With a CD,0 value of 0.0291 I got a (L/D)max value of 13.2. A higher CD,0 value needs a higher thrust_scalar value for the same level flight cruise speed at sea level.

MSFS 2020 has no propeller drag and no ground effects. As workaround I use increased gear drag and flaps drag with the drag_coef_gear and drag_coef_flaps parameters. TBM930 behavior "feels right" for me if the airspeed drops to 50% in airplane landing configuration.

[AIRPLANE_GEOMETRY]
wing_incidence = 0 ; const
oswald_efficiency_factor = 0.77 ; const
htail_incidence = 2 ; const

[FLIGHT_TUNING]
cruise_lift_scalar = 1 ; const
parasite_drag_scalar = 1 ; const
induced_drag_scalar = 1.5 ; 1.2 (sailplane, low power airplane) to 1.5 (piston, turboprop)
flap_induced_drag_scalar = 1.5 ; see induced_drag_scalar
pitch_stability = 0.05 ; const
roll_stability = 0.05 ; const
yaw_stability = 0.05 ; const

[AERODYNAMICS]
drag_coef_zero_lift = 0.07 ; 0.01 (sailplane), 0.035 (GA plane), 0.05 (aerobatics plane)
compute_aero_center = 0 ; const
aero_center_lift = 0 ; const
lift_coef_at_drag_zero = 0.1 ; const
lift_coef_at_drag_zero_flaps = 0.1 ; const

cruise_speed = 266 ; 330 ; Knots True (KTAS)
thrust_scalar = 3.8 ; 1.25 ; Propeller thrust scalar
After changing the polar, changing of thrust is needed, too. I give the airplane thrust for 266 KIAS maximum level flight airspeed at sea level.

toe_brakes_scale = 0.8 ; 0.66 ; Brake scalar
More thrust power needs more "brake power" to hold airplane still on ground at full throttle.

fuel_flow_scalar = 0.97 ; 1 ; Fuel flow scalar
Set fuel consumption to 5h at 75% LVR.

Engine.0 = 0, 0, 0.8 ; -4.3, 0, 0.8 ; 
This is the "Static thrust bug on multi engines (and Icon A5) found!" workaround. See https://forums.flightsimulator.com/t/static-thrust-bug-on-multi-engines-and-icon-a5-found/344329
The engine.X.longitudial has to be positive and lateral has to be zero to avoid the "no static thrust" bug.

empty_weight_CG_position = -16.26, 0, 0.5 ; -16, 0, 0.5 ; Position of airplane empty weight CG relative to reference datum (FEET), z, x, y
Move center of gravity to 25% MAC

flaps-position.0 = 0, -1, 0 ; 0, -1, 0.25
flaps-position.1 = 10, 178, 1 ; 10, 178, 0.25
flaps-position.2 = 34, 122, 1
The flaps drag results from sub-parameter Drag Coeff and flaps angle. Therefore 0 for 0° flaps and 1 for other settings gives linear progression of drag with flaps angle.

lift_scalar = 1 ; 1.64 ; Scalar coefficient to ponderate global flap lift coef (non dimensioned)
drag_scalar = 1 ; 1.64 ; Scalar coefficient to ponderate global flap drag coef (non dimensioned)
pitch_scalar = 1 ; 0 ; Scalar coefficient to ponderate global flap pitch coef (non dimensioned)
lift_coef_flaps = 0
drag_coef_flaps = 0.1
I control flaps lift/drag via [AERODYNAMICS] parameters.

point.0 = 1,   -7.5,   0,   -4.14,  720, 0, 0.52, 45, 0.327, 1.5, 0.9, 13, 13, 0, 0, 0, 4 ; 1,   -7.5,   0,   -4.14,  720, 0, 0.52, 15, 0.327, 1.5, 0.9, 13, 13, 0, 0, 0, 4
Better maneuverability at ground.

wing_pos_apex_lon = -14.8 ; -13.46582 ; Longitudinal (z) position of wing apex w.r.t reference datum (FEET)
wing_pos_apex_vert = 4.3 ; 4.2 ; Vertical (y) position of wing apex w.r.t reference datum (FEET)
Adjust to 3D model.

wing_incidence = 0 ; 2 ; Wing incidence (DEGREES)
htail_incidence = 0.2 ; 1 ; Horizontal tail incidence (DEGREES)
Adjust for level flight at cruise speed without elevator input.

fuselage_length = 30.8 ; -1 ; Nose to vtail/htail apex (FEET)
fuselage_diameter = 5.7
fuselage_center_pos = -17.9, 0, 1.0 ; -16, 0, 1.0
Adjust for good Aircraft Editor, Debug, Sim Forces display.

elevator_trim_neutral = 0 ; 2 ; Elevator trim max angle (absolute value) (DEGREES), for indicators only (no influence on flight model)
This is a green area in the non-cockpit elevator trim display.

cruise_lift_scalar = 1.0 ; 
parasite_drag_scalar = 1.0 ; 
drag_coef_zero_lift = 0.06 ; 0.02550
I control wings lift/drag via [AERODYNAMICS] parameters.

lift_coef_flaps = 0 ; 1.03210
lift_coef_spoilers = 0.00000
drag_coef_flaps = 0.2 ; 0.18440
drag_coef_gear = 0.05 ; 0.01000
drag_coef_spoilers = 0.00000
Airplane has flaps and rectractable gear, but no spoilers.

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