WOLFRAM SYSTEM MODELER
SchweizerSGS136Model of Schweizer SGS 136 using statespace representation 
SystemModel["Aircraft.StateSpace.FixedWing.SchweizerSGS136"]
This model extends the DefaultAircraft model and contains the parameters of the Schweizer SGS 136.
[1] Sim, A. G. (1990). Flight Characteristics of a Modified Schweizer SGS 136 Sailplane at Low and Very High Angles of Attack.
Available at: https://ntrs.nasa.gov/api/citations/19910000766/downloads/19910000766.pdf.
x0y0 
Value: {0, 0} Type: Position[2] (m) Description: Initial lateral position of the aircraft (x and y coordinates in world frame) 

refVtot 
Value: 100 Type: Velocity (m/s) Description: Total velocity for reference flight condition (Also used as initial velocity) 
refAlt 
Value: 1000 Type: Height (m) Description: Altitude for reference flight condition (Also used as initial altitude) 
refGamma 
Value: 0 Type: Angle (rad) Description: Flight path for reference flight condition (Becomes a variable if no propulsion) 
CDW0 
Value: 0.013 Type: Real Description: Drag coefficient of wingbody at zero lift 
CmW0 
Value: 0.00 Type: Real Description: Moment coefficient of wingbody at alpha = 0 
CLalphaWing3D 
Value: 4.5 Type: Real (rad⁻¹) Description: Change in the lift coefficient of the wingbody due to alpha 
mAC 
Value: 396.43973138 Type: Mass (kg) Description: Aircraft mass 
xCMdry 
Value: 0.999744 * 0.15 Type: Length (m) Description: Aircraft center of mass from wing leading edge at mean chord (positive xaxis towards nose) 
IxxDry 
Value: 1375 Type: MomentOfInertia (kg⋅m²) Description: Aircraft moment of inertia about xaxis 
IyyDry 
Value: 869 Type: MomentOfInertia (kg⋅m²) Description: Aircraft moment of inertia about yaxis 
IzzDry 
Value: 2214 Type: MomentOfInertia (kg⋅m²) Description: Aircraft moment of inertia about zaxis 
ARwing 
Value: bWing ^ 2 / SrefWing Type: Real Description: Main wing aspect ratio 
TRwing 
Value: cWingTip / cWingRoot Type: Real Description: Main wing taper ratio 
etaWing 
Value: 1 / (Modelica.Constants.pi * ARwing * kdWing * CDW0 + 1 / (0.99 * sdWing)) Type: Real Description: Oswald efficiency factor for main wing 
sdWing 
Value: 0.9998 + 0.0421 * (wFus / bWing)  2.6286 * (wFus / bWing) ^ 2 + 2 * (wFus / bWing) ^ 3 Type: Real Description: Fuselage drag factor for main wing 
Kw 
Value: 1 / (Modelica.Constants.pi * ARwing * etaWing) Type: Real Description: Induced drag factor for main wing 
bWing 
Value: 14.072616 Type: Length (m) Description: Main wing span 
cWingTip 
Value: 0.576072 Type: Length (m) Description: Main wing root chord (where wing intersects with fuselage) 
cWingRoot 
Value: 1.28016 Type: Length (m) Description: Main wing root chord (where wing intersects with fuselage) 
alphaw0 
Value: 0.0776671517137477 Type: Angle (rad) Description: Zerolift angle of attack of wing 
gammaWing 
Value: 0.0698131700797732 Type: Angle (rad) Description: Main wing dihedral angle 
SrefWing 
Value: 13.0733157888 Type: Area (m²) Description: Main wing reference area 
xWingAC 
Value: 0.999744 * 0.25 Type: Length (m) Description: Main wing aerodynamic center from wing leading edge at mean chord (positive xaxis towards nose) 
iWing 
Value: 0 Type: Angle (rad) Description: Main wing incidence angle 
cWingMean 
Value: 0.999744 Type: Length (m) Description: Main wing mean chord length 
lambdaWing 
Value: 0 Type: Angle (rad) Description: Main wing sweep angle at 1/4 chord 
epsilon0 
Value: 0.0349065850398866 Type: Angle (rad) Description: Zerolift downwash angle 
CDHT0 
Value: 0.025 Type: Real Description: Drag coefficient of horizontal tail at zero lift 
vHT 
Value: SrefHT / SrefWing * (lHTcm / cWingMean) Type: Real Description: Horizontal tail volume coefficient 
ARht 
Value: bHT ^ 2 / SrefHT Type: Real Description: Aspect ratio of horizontal tail 
CLalphaHT3D 
Value: 4 Type: Real (rad⁻¹) Description: Change in the lift coefficient of the horizontal tail due to alpha 
tauElv 
Value: 1.129 * (Selv / SrefHT) ^ 0.4044  0.1772 Type: Real Description: Elevator effectiveness parameter 
SrefHT 
Value: 1.221674976 Type: Area (m²) Description: Horizontal tail reference area 
lHTcm 
Value: 4.48 Type: Length (m) Description: Horizontal tail arm length (from aircraft center of mass to 1/4 chord) 
iHT 
Value: 0.0331612557878923 Type: Angle (rad) Description: Horizontal tail incidence angle 
Selv 
Value: 0.4162056192 Type: Area (m²) Description: Elevator area 
bHT 
Value: 2.414016 Type: Length (m) Description: Horizontal tail span 
kdHT 
Value: 3.333 * 10 ^ (4) * lambdaHT ^ 2 + 6.667 * 10 ^ (5) * lambdaHT + 0.38 Type: Real Description: Empirical constant for Oswald efficiency factor for horizontal tail 
etaHT 
Value: 1 / (Modelica.Constants.pi * ARht * kdHT * CDHT0 + 1 / (0.99 * sdHT)) Type: Real Description: Oswald efficiency factor for horizontal tail 
sdHT 
Value: 0.9998 + 0.0421 * (dFusHT / bHT)  2.6286 * (dFusHT / bHT) ^ 2 + 2 * (dFusHT / bHT) ^ 3 Type: Real Description: Fuselage drag factor for horizontal tail 
lambdaHT 
Value: 0 Type: Angle (rad) Description: Horizontal tail sweep angle at 1/4 chord 
lVTcm 
Value: 4.62 Type: Length (m) Description: Vertical tail arm length (from aircraft center of mass to vertical tail 1/4 chord) 
zVTacCM 
Value: 0.80 Type: Length (m) Description: zcoordinate w.r.t. aircraft center of mass of center of pressure of vertical tail 
etaVT 
Value: 0.8 Type: Real Description: Vertical tail efficiency factor 
SrefVT 
Value: 0.9699077376 Type: Area (m²) Description: Vertical tail reference area 
vVT 
Value: SrefVT / SrefWing * (lVTcm / bWing) Type: Real Description: Vertical tail volume coefficient 
tauRdr 
Value: 1.129 * (Srdr / SrefVT) ^ 0.4044  0.1772 Type: Real Description: Rudder effectiveness parameter 
Srdr 
Value: 0.4385023488 Type: Area (m²) Description: Rudder area 
dFusHT 
Value: 0.22 Type: Length (m) Description: Fuselage diameter at horizontal tail 1/4 chord 
wFus 
Value: 0.62 Type: Length (m) Description: Fuselage maximum width 
nEng 
Value: 0 Type: Integer Description: Number of engines 
zTau 
Value: 0 Type: Length (m) Description: zcoordinate w.r.t. aircraft center of mass of thrust line for side (#25) engines and single engine 
zTauMid 
Value: Type: Length (m) Description: zcoordinate w.r.t. aircraft center of mass of thrust line for middle (#1) engine 
zTauTotal 
Value: if nEng == 3 then (zTau * 2 + zTauMid) / 3 else zTau Type: Length (m) Description: zcoordinate of thrust line 
Tstatic 
Value: 0 Type: Force (N) Description: Static thrust of one engine at sea level 
negThrust 
Value: Type: Real Description: Maximum negative thrust (0 to 1 of thrust available) 
kappa 
Value: Type: Angle (rad) Description: Engine thrust line angle for side (#25) engines and single engine 
deltaElvMax 
Value: 0.392699081698724 Type: Angle (rad) Description: Maximum elevator deflection 
deltaAilMax 
Value: 0.392699081698724 Type: Angle (rad) Description: Maximum aileron deflection 
deltaRdrMax 
Value: 0.785398163397449 Type: Angle (rad) Description: Maximum rudder deflection 
kCnDeltaAil 
Value: 0.05 Type: Real Description: Empirical factor for the yaw moment derivative due to ailerons. Based on Figure 3.12 in Flight Stability and Automatic Control 2nd Edition 
tauAil 
Value: 1.129 * (Sail / SrefWing) ^ 0.4044  0.1772 Type: Real Description: Aileron effectiveness parameter 
Sail 
Value: cAil * (yAilTip  yAilRoot) * 2 Type: Area (m²) Description: Aileron area (of both wings) 
cAil 
Value: 0.194 Type: Length (m) Description: Aileron average chord 
yAilRoot 
Value: 4.37 Type: Length (m) Description: Aileron root ycoordinate w.r.t. fuselage centerline 
yAilTip 
Value: 6.98 Type: Length (m) Description: Aileron tip ycoordinate w.r.t. fuselage centerline 
cAilWingRoot 
Value: 0.90 Type: Length (m) Description: Local main wing chord at aileron root 
cAilWingTip 
Value: 0.60 Type: Length (m) Description: Local main wing chord at aileron tip 
kdWing 
Value: 3.333 * 10 ^ (4) * lambdaWing ^ 2 + 6.667 * 10 ^ (5) * lambdaWing + 0.38 Type: Real Description: Empirical constant for Oswald efficiency factor for main wing 
epsilonAlpha 
Value: 2 * CLalphaWing3D / (Modelica.Constants.pi * ARwing) Type: Real Description: Change in downwash due to alpha 
sigmaBeta 
Value: 0.1 Type: Real Description: Change in sidewash due to beta 
CLhtDeltaElv 
Value: CLalphaHT3D * tauElv Type: Real (rad⁻¹) Description: C_L_HT_delta_e (Coefficient for change in the lift coefficient of the horizontal tail due to elevator deflection) 
ClbetaGamma 
Value: 0.66 Type: Real (rad⁻²) Description: Empirical factor for C_l_beta/gammaWing. 0.66/rad^2 is a decent universal approximation 
CLdeltae 
Value: SrefHT / SrefWing * etaHT * CLhtDeltaElv Type: Real (rad⁻¹) Description: C_L_delta_e (Coefficient for change in the lift coefficient of entire aircraft due to elevator deflection) 
CLalpha 
Value: 5 Type: Real (rad⁻¹) Description: Change in the lift coefficient due to alpha 
CLalphaVT3D 
Value: 4 Type: Real (rad⁻¹) Description: Change in the lift coefficient of the vertical tail due to alpha 
CDalpha 
Value: 0.23 Type: Real (rad⁻¹) Description: Change in C_D due to alpha 
CDM 
Value: 0.002 Type: Real Description: Change in C_D due to Mach number 
CMM 
Value: 0.002 Type: Real Description: Change in C_M due to Mach number 
Cmdeltae 
Value: etaHT * vHT * CLhtDeltaElv Type: Real (rad⁻¹) Description: C_m_delta_e (Coefficient for change in pitch moment due to elevator deflection) 
Cmq 
Value: Cmalphadot / epsilonAlpha Type: Real (rad⁻¹) Description: C_m_q (Coefficient for change in pitch moment due to pitch rate) 
Cmalphadot 
Value: 2 * etaHT * CLalphaHT3D * vHT * (lHTcm / cWingMean) * epsilonAlpha Type: Real (rad⁻¹) Description: C_m_alphadot (Coefficient for change in pitch moment due to alphadot) 
Cmalpha 
Value: 1.29 Type: Real (rad⁻¹) Description: Change in C_M due to alpha 
CyDeltaRdr 
Value: SrefVT / SrefWing * tauRdr * CLalphaVT3D Type: Real (rad⁻¹) Description: Yforce due to rudder deflection control derivative 
ClDeltaAil 
Value: 2 * CLalpha * tauAil / (SrefWing * bWing) * (yAilTip ^ 2 / 2  yAilRoot ^ 2 / 2) * (cAilWingRoot * 2 / 3 * (1 + cAilWingTip / cAilWingRoot + (cAilWingTip / cAilWingRoot) ^ 2) / (1 + cAilWingTip / cAilWingRoot)) Type: Real (rad⁻¹) Description: Roll moment due to aileron deflection control derivative 
Cldeltar 
Value: SrefVT / SrefWing * abs(zVTacCM) / bWing * tauRdr * CLalphaVT3D Type: Real (rad⁻¹) Description: C_l_delta_r (Coefficient for change in roll moment due to rudder deflection) 
Cndeltar 
Value: vVT * etaVT * tauRdr * CLalphaVT3D Type: Real (rad⁻¹) Description: C_n_delta_r (Coefficient for change in yaw moment due to rudder deflection) 
CyBeta 
Value: etaVT * SrefVT / SrefWing * CLalphaVT3D * (1 + sigmaBeta) Type: Real (rad⁻¹) Description: Yforce due to sideslip angle stability derivative 
Cnr 
Value: 2 * etaVT * vVT * lVTcm / bWing * CLalphaVT3D Type: Real Description: C_n_r (Coefficient for change in yaw moment due to yaw rate) 
Cyr 
Value: 2 * lVTcm / bWing * CyBeta Type: Real (rad⁻¹) Description: C_y_r (Coefficient for change in Yforce due to yaw rate) 
ClRoll 
Value: CLalpha / 12 * (1 + 3 * TRwing) / (1 + TRwing) Type: Real (rad⁻¹) Description: C_l_p (Coefficient for change in roll moment due to roll rate) 
Cnbeta 
Value: etaVT * vVT * CLalphaVT3D * (1 + sigmaBeta) Type: Real (rad⁻¹) Description: C_n_beta (Coefficient for change in yaw moment due to sideslip angle) 
Clbeta 
Value: ClbetaGamma * gammaWing Type: Real (rad⁻¹) Description: C_l_beta (Coefficient for change in roll moment due to sideslip angle) 
reference 
Type: RefFlightSignalBus Description: Bus for the real signals of the reference flight conditions 


motion 
Type: MotionSignalBus Description: Bus for the real signals of the linear and angular velocity perturbations resolved in the body frame 

DdeltaaIn 
Type: RealInput Description: 'input Real' as connector 

DdeltaTIn 
Type: RealInput Description: 'input Real' as connector 

DdeltaeIn 
Type: RealInput Description: 'input Real' as connector 

DdeltarIn 
Type: RealInput Description: 'input Real' as connector 

position 
Type: PositionSignalBus Description: Bus for the real signals of position, orientation and velocities resolved in the world frame 
trimCalculator 
Type: TrimCalculator Description: Calculates trimmed conditions for given flight conditions 


longitudinalMotion 
Type: LongitudinalMotion Description: State space representation of longitudinal motion 

lateralMotion 
Type: LateralMotion Description: State space representation of lateral motion 

lateralDerivatives 
Type: LateralDerivatives Description: Calculates lateral stability and control derivatives 

positionAndOrientation 
Type: PositionAndOrientation Description: Calculates the position, orientation and velocities of the aircraft in the world frame 

longitudinalDerivatives 
Type: LongitudinalDerivatives Description: Calculates longitudinal stability and control derivatives 

refVtotExpr 
Type: RealExpression Description: Total velocity of reference flight conditions 

refAltExpr 
Type: RealExpression Description: Altitude of reference flight conditions 

refGammaExpr 
Type: RealExpression Description: Flight path of reference flight conditions 

throttleDynamics 
Type: CriticalDamping Description: Damper for simplified model of throttle dynamics 

elevatorDynamics 
Type: CriticalDamping Description: Damper for simplified model of elevator dynamics 

aileronDynamics 
Type: CriticalDamping Description: Damper for simplified model of aileron dynamics 

rudderDynamics 
Type: CriticalDamping Description: Damper for simplified model of rudder dynamics 

DeltarLimiter 
Type: Limiter Description: Limits rudder deflection to its assigned limits 

DeltaaLimiter 
Type: Limiter Description: Limits aileron deflection to its assigned limits 

deltaElvLimiter 
Type: VariableLimiter Description: Limit the range of a signal with variable limits 

maxDeltaElv 
Type: RealExpression Description: Upper limit for elevator deflection 

minDeltaElv 
Type: RealExpression Description: Lower limit for elevator deflection 

maxDeltaThrot 
Type: RealExpression Description: Upper limit for throttle position 

minDeltaThrot 
Type: RealExpression Description: Lower limit for throttle position 

deltaThrotLimiter 
Type: VariableLimiter Description: Limit the range of a signal with variable limits 