SITL: improve ICEngine simulation

libraries/SITL/SIM_ICEngine.cpp

@@ -84,9 +84,12 @@ float ICEngine::update(const Aircraft::sitl_input &input)
     }
     if (start_time_us != 0 && state.starter) {
         uint32_t starter_time_us = (now - start_time_us);
-        if (starter_time_us > 3000*1000UL) {
+        if (starter_time_us > 3000*1000UL && !overheat) {
+            overheat = true;
             printf("Starter overheat\n");            
         }
+    } else {
+        overheat = false;
     }
 
 output:

libraries/SITL/SIM_ICEngine.h

@@ -54,5 +54,6 @@ private:
         };
         uint8_t value;
     } state, last_state;
+    bool overheat:1;
 };
 }

libraries/SITL/SIM_Plane.cpp

@@ -250,6 +250,9 @@ void Plane::calculate_forces(const struct sitl_input &input, Vector3f &rot_accel
     Vector3f force = getForce(aileron, elevator, rudder);
     rot_accel = getTorque(aileron, elevator, rudder, force);
 
+    // simulate engine RPM
+    rpm1 = thrust * 7000;
+    
     // scale thrust to newtons
     thrust *= thrust_scale;
 

libraries/SITL/SIM_Plane.h

@@ -98,7 +98,7 @@ protected:
     bool reverse_elevator_rudder;
     bool ice_engine;
 
-    ICEngine icengine{2, 4, 5, 6, 100};
+    ICEngine icengine{2, 14, 12, 13, 100};
 
     float liftCoeff(float alpha) const;
     float dragCoeff(float alpha) const;