********************************************************************************
Flight Dynamics for the Savoia Marchetti S.M.81 with Alfa Romeo 126/RC34 engines
********************************************************************************
[fltsim.0]
title=SM81 AR126 Spain 1
sim=SM81_AR126
model=
panel=
sound=
texture=sn_1
kb_checklists=
kb_reference=SM81_AR126ref
atc_id=1
ui_manufacturer=Savoia Marchetti
ui_type=S.81 - Alfa Romeo AR126/RC34 engines
ui_variation=Spanish Nationalist Air Force (A)
atc_heavy=0
atc_airline=
atc_flight_number=
description=This was the final version of the S.81. Deployed from late 1936 it had the most powerful engines and the best performance. It was optimised for use as a medium level bomber within Europe, but had a secondary maritime patrol capability. About sixty five Alfa Romeo powered S.M.81s flew combat missions with the Spanish Nationalist Air Forces during the civil war. Skin by Manuele Villa, April 2008.

[fltsim.1]
title=SM81 AR126 Spain 2
sim=SM81_AR126
model=
panel=
sound=
texture=sn_2
kb_checklists=
kb_reference=SM81_AR126ref
atc_id=21-42
ui_manufacturer=Savoia Marchetti
ui_type=S.81 - Alfa Romeo AR126/RC34 engines
ui_variation=Spanish Nationalist Air Force (B)
atc_heavy=0
atc_airline=
atc_flight_number=
description=This was the final version of the S.81. Deployed from late 1936 it had the most powerful engines and the best performance. It was optimised for use as a medium level bomber within Europe, but had a secondary maritime patrol capability. About sixty five Alfa Romeo powered S.M.81s flew combat missions with the Spanish Nationalist Air Forces during the civil war. Skin by Manuele Villa, April 2008.

[fltsim.2]
title=SM81 AR126 202-5
sim=SM81_AR126
model=
panel=
sound=
texture=202-5
kb_checklists=
kb_reference=SM81_AR126ref
atc_id=202-5
ui_manufacturer=Savoia Marchetti
ui_type=S.81 - Alfa Romeo AR126/RC34 engines
ui_variation=202nd Sq./40th Grp./38th Stormo B.T.
atc_heavy=0
atc_airline=
atc_flight_number=
description=This was the final version of the S.81. Deployed from late 1936 it had the most powerful engines and the best performance. It was optimised for use as a medium level bomber within Europe, but had a secondary maritime patrol capability. This plane, based on Tirana's airport (Albania) during 1941, belonged to 202nd Sq./40th Grp./38th Stormo B.T. Skin by Manuele Villa, April 2008.

[General]

atc_type=
atc_model=
performance=Press F10 and then lowest icon for step by step on screen handling notes.

[Views]

eyepoint = 6.35, -0.85, 3


[WEIGHT_AND_BALANCE]

empty_weight     = 15907	;including lubricating oil, flares, guns and ammunition
max_gross_weight = 23157	

Due to the very strong landing gear it was safe to land the S.81 at max gross after an emergency return. 

reference_datum_position     = 0, 0, 0
empty_weight_CG_position     = 0, 0, 0

station_load.0 = 1000, 0, 0, 0 	;5 crew with parachutes
station_load.1 = 2200, 0, 0, 0 	;normal bombload


Moments of Inertia

empty_weight_pitch_MOI   = 120000
empty_weight_roll_MOI    = 260000
empty_weight_yaw_MOI     = 300000 

empty_weight_coupled_MOI = 0.000     

      


[fuel]

Max fuel was 5765lbs = 961 USG modern unleaded AVGAS

The real aircraft had eight tanks, six of which were between the engines. Outboard tanks were used only for overload maritime patrol.

The S.81 had a maximum bomb load of 2,000Kg but the normal bomb load was half that which allowed 1820Kg of AVGAS to be loaded for a typical mission. When carrying the maximum possible bomb load of 2000Kg the maximum fuel load is 820Kg.

Those who wish to complicate the roll and yaw handling can move the left right tanks a few feet either side of CoG.

LeftMain  = 0, 0, 0, 287, 0	
RightMain = 0, 0, 0, 287, 0	
Center1   = 0, 0, 0,  93, 0

//Center2   = 0, 0, 0,  294, 0 ;after removing all bombload remove the // to simulate overload maritime patrol mission with max auxiliary fuel


fuel_type = 1                               
number_of_tank_selectors=1
electric_pump=0




[GeneralEngineData]

engine_type = 0
Engine.0 =  4.2, -9.6, -2.3
Engine.1 = 12.2,    0,  0
Engine.2 =  4.2,  9.6, -2.3
min_throttle_limit = 0.1                      
master_ignition_switch = 1  

fuel_flow_scalar = 1		

**************

[piston_engine]

The Alfa Romeo 126/R.C.34 

TOGA = 780hp at 1.125 C2 and variable rpm below 3500 metres

War Emergency = 780hp at 1.125 C2 and max 2400 rpm below 3500 metres

(Combat) Rated Power = 750hp at 1.11 C2 and max 2300 rpm at 3400 metres

METO = 680hp


critical_altitude=11480		//War Emergency
cylinder_displacement=194.78
compression_ratio=6.5
number_of_cylinders=9
max_rated_rpm=2400		//TOGA and War Emergency
max_rated_hp=780		//TOGA and War Emergency

fuel_metering_type=1
cooling_type=0
normalized_starter_torque=0.5
turbocharged=1
max_design_mp=33.66		
min_design_mp=0

emergency_boost_type=0
emergency_boost_mp_offset=0.000000
emergency_boost_gain_offset=0.000000
fuel_air_auto_mixture=0
auto_ignition=0
max_rpm_mechanical_efficiency_scalar=1.000000
idle_rpm_mechanical_efficiency_scalar=1.000000
max_rpm_friction_scalar=1.000000
idle_rpm_friction_scalar=1.000000

[propeller]


propeller_type=1
propeller_blades=3
gear_reduction_ratio=1.53			
propeller_diameter=12.9			
propeller_moi=10
fixed_pitch_beta=20		   		
beta_max=0					
beta_min=0	
prop_sync_available=0                         
prop_deice_available=0                       
prop_feathering_available=0    
prop_reverse_available=0                                    
min_rpm_for_feather=0                       
beta_feather=0.0                               
power_absorbed_cf=0                           
minimum_on_ground_beta=10.0				
minimum_reverse_beta=0                     
defeathering_accumulators_available=0            
prop_auto_feathering_available=0             
min_gov_rpm=650.000000
prop_tc=0.010000

low_speed_theory_limit=80.000000



[airplane_geometry]

oswald_efficiency_factor= 0.67	  

wing_area               = 992.4 	;92.2 square metres
wing_span               = 78.7		;24 metres	
wing_root_chord         = 16.9
wing_pos_apex_lon       = 3.25
wing_pos_apex_vert      = -2.500
htail_area              = 175.000
htail_span              = 20.000
htail_pos_lon           = -36.000
htail_pos_vert          = 0.000
htail_incidence         = 0.000
htail_sweep             = 40.000
vtail_area              = 81.200
vtail_span              = 10.000
vtail_sweep             = 45.000
vtail_pos_lon           = -36.000
vtail_pos_vert          = 3.400
elevator_area           = 75.000
aileron_area            = 37.100
rudder_area             = 37.000
elevator_up_limit       = 18.000
elevator_down_limit     = 15.000
aileron_up_limit        = 18.000
aileron_down_limit      = 18.000
rudder_limit            = 25.000
elevator_trim_limit     = 15.000
spoiler_limit           = 60		;used for turret drag
spoilerons_available    = 0
aileron_to_spoileron_gain = 0
min_ailerons_for_spoilerons = 0
min_flaps_for_spoilerons = 0
wing_dihedral           = 0
wing_incidence          = 0
wing_twist              = 0
wing_winglets_flag      = 0
wing_sweep              = 0

               
[Flaps.0]

Slow moving hand pumped flaps. Technical manual has only caution against use at 'high' IAS. The pump would break and the flaps would 'stick'. More or less self resolving in real life as they were too difficult to hand pump at high IAS. Vfe nominally set at 250 KmIAS, but correct IAS for deployment of each stage much lower and specified within the handling notes.

type= 1
span-outboard= 0.550
extending-time= 24			
system_type= 3

flaps-position.0= 0,0
flaps-position.1= 13, 138		
flaps-position.2= 19, 138		
flaps-position.3= 38, 138	

[Reference Speeds]

flaps_up_stall_speed    =  57		
full_flaps_stall_speed  =  49		
cruise_speed            = 170		
max_indicated_speed     = 170		

Some care must be exercised to moderate profile drag (IAS) < 310 KmIAS (but especially when descending) to avoid structural failure of the tail. Due to the high drag of the fixed gear this was not a material problem in real life. 

	
[Radios]


Com.1         = 1, 0
Com.2         = 0, 0
Nav.1         = 1, 0, 0		
Nav.2         = 0, 0, 0
Adf.1         = 1		
Adf.2         = 0
Transponder.1 = 1		
Audio.1       = 1
Marker.1      = 1		

[contact_points]
//GEAR
point.0 = 1, -40.67,  0,  -3.1, 1200, 0, 1.01, 40, 0.3 , 2.5, 0.9 , 0, 0, 0, 0, 0
point.1 = 1,   1, -8.82, -10.8, 1600, 1, 1.98,  0, 0.4 , 2.5, 0.85, 0, 0, 2, 0, 0
point.2 = 1,   1,  8.82, -10.8, 1600, 2, 1.98,  0, 0.4 , 2.5, 0.85, 0, 0, 3, 0, 0

//SCRAPES
point.3= 2, -1.600, -39.000, 0.000, 800.000, 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, -1.600, 39.000, 0.000, 800.000, 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, -44.100, 0.000, 0.81, 800.000, 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, 16.45, 0.000, -6.07, 800.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 4.000, 0.000, 0.000
point.7= 2, 7.64, -9.56, -8.25, 800.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 4.000, 0.000, 0.000
point.8= 2, 7.64, 9.56, -8.25, 800.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 4.000, 0.000, 0.000

static_pitch = 11
static_cg_height = 10.3
tailwheel_lock = 0 


[brakes]
parking_brake    = 1     
toe_brakes_scale = 0.25  ;drum brakes at this date were ineffective and subject to fading


[hydraulic_system]
normal_pressure = 732.0     //PSI
electric_pumps  = 0         //no electric pumps
engine_map      = 1,1,0   //pumps on Eng1,2


[LIGHTS]
//Types: 1=beacon, 2=strobe, 3=navigation, 4=cockpit, 5=landing
light.0 = 3, -5.59, -39.13, 0.06, fx_navred
light.1 = 3, -5.59, 39.16, 0.1, fx_navgre
light.2 = 3, -44.06, 0, 0.87, fx_navwhi
light.3 = 4, 7.2, 0, 2.46, fx_vclight
light.4 = 4,  -16.2,   0,  1, fx_vclight
light.5 = 5, -6.45, 19.19, -2.87, fx_SM74_landing
light.6 = 5, -6.55, -19.19, -2.87, fx_SM74_landing


[keyboard_response]
elevator =200, 1000
aileron  =200, 1000
rudder   =200, 1000

[direction_indicators]

direction_indicator.0=1,0
direction_indicator.1=2,0

[attitude_indicators]

attitude_indicator.0 = 1 
attitude_indicator.1 = 2 

[turn_indicators]

turn_indicator.0=2,0

[autopilot]
autopilot_available= 1
direction_indicator=1
attitude_indicator =0
default_pitch_mode=0	// no pich control
max_bank=25		
max_bank_acceleration=1
max_bank_velocity=3
default_bank_mode=2     
default_vertical_speed=0
autothrottle_available=0
pitch_takeoff_ga=8.000000
max_pitch=0
max_pitch_acceleration=0
max_pitch_velocity_lo_alt=0
max_pitch_velocity_hi_alt=0
max_pitch_velocity_lo_alt_breakpoint=0
max_pitch_velocity_hi_alt_breakpoint=0
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


[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						;unlikely in real life

[exits]
number_of_exits = 2
exit_rate.0 = 0.27                              ;Percent per second
exit_rate.1 = 0.5                               ;Percent per second

[EFFECTS]
wake=fx_wake
water=fx_spray
dirt=fx_tchdrt
concrete=fx_sparks
startup=fx_engstrt_jenny
touchdown=fx_tchdwn_s, 1


[electrical]
max_battery_voltage = 12
generator_alternator_voltage = 12
max_generator_alternator_amps = 90

[flight_tuning]

p_factor_on_yaw          = 0.0
torque_on_roll           = 0.0
gyro_precession_on_yaw   = 0.0
gyro_precession_on_pitch = 0.0
