Curt:

Stub in hooks for Propeller feathering controls and the turbo prop "condition"
lever.

I added a line in FGFDM.cpp to force control properties to exist if they
don't already.  This way you can specify anything you want and find them
in the property browser, otherwise no one else may create them and you are
stuck.

In PropEngine::solve() the code original sets _running = true at the
beginning and then sets running = false at the end.  I changed this to
save the current value at the start, set to true, solve(), and then
restore the original value at the end.  That way if we start off with
_running = true, we don't have to hack up the calc() routine which wasn't
using the value anyway.

Finally I added some very initial support to shut down a turbine engine
(_running = false) when the condition lever goes to zero.

src/FDM/YASim/ControlMap.cpp

@@ -2,6 +2,7 @@
 #include "Thruster.hpp"
 #include "PropEngine.hpp"
 #include "PistonEngine.hpp"
+#include "TurbineEngine.hpp"
 #include "Gear.hpp"
 #include "Wing.hpp"
 #include "Rotor.hpp"
@@ -186,10 +187,12 @@ void ControlMap::applyControls(float dt)
 	switch(o->type) {
 	case THROTTLE: ((Thruster*)obj)->setThrottle(lval);        break;
 	case MIXTURE:  ((Thruster*)obj)->setMixture(lval);         break;
+        case CONDLEVER: ((TurbineEngine*)((PropEngine*)obj)->getEngine())->setCondLever(lval); break;
 	case STARTER:  ((Thruster*)obj)->setStarter(lval != 0.0);  break;
 	case MAGNETOS: ((PropEngine*)obj)->setMagnetos((int)lval); break;
 	case ADVANCE:  ((PropEngine*)obj)->setAdvance(lval);       break;
         case PROPPITCH: ((PropEngine*)obj)->setPropPitch(lval);    break;
+        case PROPFEATHER: ((PropEngine*)obj)->setPropFeather((int)lval); break;
 	case REHEAT:   ((Jet*)obj)->setReheat(lval);               break;
 	case VECTOR:   ((Jet*)obj)->setRotation(lval);             break;
 	case BRAKE:    ((Gear*)obj)->setBrake(lval);               break;

src/FDM/YASim/ControlMap.hpp

@@ -9,11 +9,11 @@ class ControlMap {
 public:
     ~ControlMap();
 
-    enum OutputType { THROTTLE, MIXTURE, STARTER, MAGNETOS,
+    enum OutputType { THROTTLE, MIXTURE, CONDLEVER, STARTER, MAGNETOS,
 		      ADVANCE, REHEAT, PROP,
 		      BRAKE, STEER, EXTEND,
 		      INCIDENCE, FLAP0, FLAP1, SLAT, SPOILER, VECTOR,
-                      BOOST, CASTERING, PROPPITCH, 
+                      BOOST, CASTERING, PROPPITCH, PROPFEATHER,
                       COLLECTIVE, CYCLICAIL, CYCLICELE, ROTORENGINEON,
                       REVERSE_THRUST };
 

src/FDM/YASim/FGFDM.cpp

@@ -393,7 +393,7 @@ void FGFDM::getExternalInput(float dt)
 
 void FGFDM::setOutputProperties()
 {
-    char buf[256];
+    // char buf[256];
     int i;
 
     float grossWgt = _airplane.getModel()->getBody()->getTotalMass() * KG2LBS;
@@ -726,6 +726,7 @@ int FGFDM::parseAxis(const char* name)
     // Not there, make a new one.
     AxisRec* a = new AxisRec();
     a->name = dup(name);
+    fgGetNode( a->name, true ); // make sure the property name exists
     a->handle = _airplane.getControlMap()->newInput();
     _axes.add(a);
     return a->handle;
@@ -735,6 +736,7 @@ int FGFDM::parseOutput(const char* name)
 {
     if(eq(name, "THROTTLE"))  return ControlMap::THROTTLE;
     if(eq(name, "MIXTURE"))   return ControlMap::MIXTURE;
+    if(eq(name, "CONDLEVER")) return ControlMap::CONDLEVER;
     if(eq(name, "STARTER"))   return ControlMap::STARTER;
     if(eq(name, "MAGNETOS"))  return ControlMap::MAGNETOS;
     if(eq(name, "ADVANCE"))   return ControlMap::ADVANCE;
@@ -752,6 +754,7 @@ int FGFDM::parseOutput(const char* name)
     if(eq(name, "SPOILER"))   return ControlMap::SPOILER;
     if(eq(name, "CASTERING")) return ControlMap::CASTERING;
     if(eq(name, "PROPPITCH")) return ControlMap::PROPPITCH;
+    if(eq(name, "PROPFEATHER")) return ControlMap::PROPFEATHER;
     if(eq(name, "COLLECTIVE")) return ControlMap::COLLECTIVE;
     if(eq(name, "CYCLICAIL")) return ControlMap::CYCLICAIL;
     if(eq(name, "CYCLICELE")) return ControlMap::CYCLICELE;

src/FDM/YASim/PropEngine.cpp

@@ -41,6 +41,12 @@ void PropEngine::setPropPitch(float proppitch)
     _prop->setPropPitch(proppitch);
 }
 
+void PropEngine::setPropFeather(int state)
+{
+    // toggle prop feathering on/off
+    _prop->setPropFeather(state);
+}
+
 void PropEngine::setVariableProp(float min, float max)
 {
     _variable = true;
@@ -99,6 +105,8 @@ void PropEngine::stabilize()
 
     _eng->setStarter(false);
     _eng->setMagnetos(3);
+
+    bool running_state = _eng->isRunning();
     _eng->setRunning(true);
 
     if(_variable) {
@@ -141,7 +149,7 @@ void PropEngine::stabilize()
     }
 
     // ...and back off
-    _eng->setRunning(false);
+    _eng->setRunning(running_state);
 }
 
 void PropEngine::init()

src/FDM/YASim/PropEngine.hpp

@@ -19,6 +19,7 @@ public:
     void setAdvance(float advance);
     void setPropPitch(float proppitch);
     void setVariableProp(float min, float max);
+    void setPropFeather(int state);
     void setGearRatio(float ratio) { _gearRatio = ratio; }
 
     virtual PropEngine* getPropEngine() { return this; }

src/FDM/YASim/Propeller.cpp

@@ -24,6 +24,7 @@ Propeller::Propeller(float radius, float v, float omega,
     _matchTakeoff = false;
     _manual = false;
     _proppitch = 0;
+    _propfeather = 0;
 }
 
 void Propeller::setTakeoff(float omega0, float power0)
@@ -55,6 +56,12 @@ void Propeller::setPropPitch(float proppitch)
     _proppitch = Math::clamp(proppitch, 0, 1);
 }
 
+void Propeller::setPropFeather(int state)
+{
+    // 0 = normal, 1 = feathered
+    _propfeather = (state != 0);
+}
+
 void Propeller::calc(float density, float v, float omega,
 		     float* thrustOut, float* torqueOut)
 {

src/FDM/YASim/Propeller.hpp

@@ -22,6 +22,8 @@ public:
 
     void setPropPitch(float proppitch);
 
+    void setPropFeather(int state);
+
     void setManualPitch();
 
     void calc(float density, float v, float omega,
@@ -39,6 +41,7 @@ private:
     bool  _matchTakeoff; // Does _tc0 mean anything?
     bool  _manual;      // manual pitch mode
     float _proppitch;   // prop pitch control setting (0 ~ 1.0)
+    float _propfeather; // prop feather control setting (0 = norm, 1 = feather)
 };
 
 }; // namespace yasim

src/FDM/YASim/Thruster.cpp

@@ -50,6 +50,7 @@ void Thruster::setMixture(float mixture)
     _mixture = Math::clamp(mixture, 0, 1);
 }
 
+
 void Thruster::setStarter(bool starter)
 {
     _starter = starter;

src/FDM/YASim/TurbineEngine.cpp

@@ -7,6 +7,8 @@ namespace yasim {
 TurbineEngine::TurbineEngine(float power, float omega, float alt,
                              float flatRating)
 {
+    // _cond_lever = 1.0;
+
     _rho0 = Atmosphere::getStdDensity(0);
     _maxTorque = (power/omega) * _rho0 / Atmosphere::getStdDensity(alt);
     _flatRating = flatRating;
@@ -19,6 +21,8 @@ TurbineEngine::TurbineEngine(float power, float omega, float alt,
     _n2 = _n2Target = _n2Min;
     _torque = 0;
     _fuelFlow = 0;
+
+    _running = true;
 }
 
 void TurbineEngine::setOutputFromN2()
@@ -46,7 +50,12 @@ void TurbineEngine::integrate(float dt)
 
 void TurbineEngine::calc(float pressure, float temp, float omega)
 {
+    if ( _cond_lever < 0.001 ) {
+        _running = false;
+    } else {
         _running = true;
+    }
+
     _omega = omega;
     _rho = Atmosphere::calcStdDensity(pressure, temp);
 
@@ -56,7 +65,12 @@ void TurbineEngine::calc(float pressure, float temp, float omega)
         torque = _flatRating / omega;
 
     float frac = torque / (_maxTorque * (_rho / _rho0));
+
+    if ( _running ) {
         _n2Target = _n2Min + (_n2Max - _n2Min) * frac;
+    } else {
+        _n2Target = 0;
+    }
 }
 
 }; // namespace yasim

src/FDM/YASim/TurbineEngine.hpp

@@ -17,6 +17,9 @@ public:
     virtual void stabilize();
     virtual void integrate(float dt);
 
+    void setCondLever( float lever ) {
+        _cond_lever = lever;
+    }
     virtual float getTorque() { return _torque; }
     virtual float getFuelFlow() { return _fuelFlow; }
     float getN2() { return _n2; }
@@ -24,6 +27,8 @@ public:
 private:
     void setOutputFromN2();
 
+    float _cond_lever;
+
     float _maxTorque;
     float _flatRating;
     float _rho0;