diff --git a/src/FDM/YASim/CMakeLists.txt b/src/FDM/YASim/CMakeLists.txt
index 0d7efa881..3065af68a 100644
--- a/src/FDM/YASim/CMakeLists.txt
+++ b/src/FDM/YASim/CMakeLists.txt
@@ -26,6 +26,7 @@ set(COMMON
 	Turbulence.cpp
 	Wing.cpp
 	Version.cpp
+	yasim-common.cpp
 	)
 
 set(SOURCES
diff --git a/src/FDM/YASim/ControlMap.cpp b/src/FDM/YASim/ControlMap.cpp
index 5e6de0478..27dddc72c 100644
--- a/src/FDM/YASim/ControlMap.cpp
+++ b/src/FDM/YASim/ControlMap.cpp
@@ -2,6 +2,7 @@
 #  include "config.h"
 #endif
 
+#include "yasim-common.hpp"
 #include "Jet.hpp"
 #include "Thruster.hpp"
 #include "PropEngine.hpp"
@@ -281,26 +282,6 @@ float ControlMap::rangeMax(Control control)
     }
 }
 
-/// duplicate null-terminated string
-char* ControlMap::dup(const char* s)
-{
-    int len=0;
-    while(s[len++]);
-    char* s2 = new char[len+1];
-    char* p = s2;
-    while((*p++ = *s++));
-    s2[len] = 0;
-    return s2;
-}
-
-/// compare null-terminated strings
-bool ControlMap::eq(const char* a, const char* b)
-{
-	while(*a && *b && *a == *b) { a++; b++; }
-	// equal if both a and b points to null chars
-	return !(*a || *b);
-}
-
 /// register property name, return ID (int)
 int ControlMap::propertyHandle(const char* name)
 {
diff --git a/src/FDM/YASim/ControlMap.hpp b/src/FDM/YASim/ControlMap.hpp
index 464676ac9..b385187bb 100644
--- a/src/FDM/YASim/ControlMap.hpp
+++ b/src/FDM/YASim/ControlMap.hpp
@@ -142,10 +142,6 @@ private:
     Vector _outputs;
     // control properties
     Vector _properties;
-
-    // helper
-    char* dup(const char* s);
-    bool eq(const char* a, const char* b);
 };
 
 }; // namespace yasim
diff --git a/src/FDM/YASim/FGFDM.cpp b/src/FDM/YASim/FGFDM.cpp
index dba161335..f5545fc7e 100644
--- a/src/FDM/YASim/FGFDM.cpp
+++ b/src/FDM/YASim/FGFDM.cpp
@@ -1114,24 +1114,6 @@ void FGFDM::parseWeight(XMLAttributes* a)
     _weights.add(wr);
 }
 
-bool FGFDM::eq(const char* a, const char* b)
-{
-    // Figure it out for yourself. :)
-    while(*a && *b && *a == *b) { a++; b++; }
-    return !(*a || *b);
-}
-
-char* FGFDM::dup(const char* s)
-{
-    int len=0;
-    while(s[len++]);
-    char* s2 = new char[len+1];
-    char* p = s2;
-    while((*p++ = *s++));
-    s2[len] = 0;
-    return s2;
-}
-
 int FGFDM::attri(XMLAttributes* atts, const char* attr)
 {
     if(!atts->hasAttribute(attr)) {
diff --git a/src/FDM/YASim/FGFDM.hpp b/src/FDM/YASim/FGFDM.hpp
index 333d0c1a2..49644163f 100644
--- a/src/FDM/YASim/FGFDM.hpp
+++ b/src/FDM/YASim/FGFDM.hpp
@@ -59,9 +59,6 @@ private:
     void parseTurbineEngine(XMLAttributes* a);
     void parsePistonEngine(XMLAttributes* a);
     void parsePropeller(XMLAttributes* a);
-    bool eq(const char* a, const char* b);
-    bool caseeq(const char* a, const char* b);
-    char* dup(const char* s);
     int attri(XMLAttributes* atts, const char* attr);
     int attri(XMLAttributes* atts, const char* attr, int def); 
     float attrf(XMLAttributes* atts, const char* attr);
diff --git a/src/FDM/YASim/Vector.hpp b/src/FDM/YASim/Vector.hpp
index f290f0ae0..5dbf8b42f 100644
--- a/src/FDM/YASim/Vector.hpp
+++ b/src/FDM/YASim/Vector.hpp
@@ -3,6 +3,8 @@
 
 #include <stdio.h>
 #include <cassert>
+
+namespace yasim {
 //
 // Excruciatingly simple vector-of-pointers class.  Easy & useful.
 // No support for addition of elements anywhere but at the end of the
@@ -78,5 +80,5 @@ inline void Vector::realloc()
     delete[] _array;
     _array = array;
 }
-
+}; //namespace yasim
 #endif // _VECTOR_HPP
diff --git a/src/FDM/YASim/yasim-common.cpp b/src/FDM/YASim/yasim-common.cpp
new file mode 100644
index 000000000..23bbf7f6a
--- /dev/null
+++ b/src/FDM/YASim/yasim-common.cpp
@@ -0,0 +1,23 @@
+#include "yasim-common.hpp"
+
+namespace yasim {
+    /// duplicate null-terminated string
+    char* dup(const char* s)
+    {
+        int len=0;
+        while(s[len++]);
+        char* s2 = new char[len+1];
+        char* p = s2;
+        while((*p++ = *s++));
+        s2[len] = 0;
+        return s2;
+    }
+
+    /// compare null-terminated strings
+    bool eq(const char* a, const char* b)
+    {
+        while(*a && *b && *a == *b) { a++; b++; }
+        // equal if both a and b points to null chars
+        return !(*a || *b);
+    }
+}; //namespace yasim
diff --git a/src/FDM/YASim/yasim-common.hpp b/src/FDM/YASim/yasim-common.hpp
index ed1c4f018..32097af7e 100644
--- a/src/FDM/YASim/yasim-common.hpp
+++ b/src/FDM/YASim/yasim-common.hpp
@@ -1,34 +1,40 @@
 #ifndef _YASIM_COMMON_HPP
 #define _YASIM_COMMON_HPP
 
+/*
+ common file for YASim wide constants and static helper functions
+ */
 namespace yasim {
-  static const float YASIM_PI = 3.14159265358979323846f;
-  static const float PI2 = YASIM_PI*2;
-  static const float RAD2DEG = 180/YASIM_PI;
-  static const float DEG2RAD = YASIM_PI/180;
-  static const float RPM2RAD = YASIM_PI/30;
+    static const float YASIM_PI = 3.14159265358979323846f;
+    static const float PI2 = YASIM_PI*2;
+    static const float RAD2DEG = 180/YASIM_PI;
+    static const float DEG2RAD = YASIM_PI/180;
+    static const float RPM2RAD = YASIM_PI/30;
 
-  static const float KTS2MPS = 1852.0f/3600.0f;
-  static const float MPS2KTS = 3600.0f/1852.0f;
-  static const float KMH2MPS = 1/3.6f;
+    static const float KTS2MPS = 1852.0f/3600.0f;
+    static const float MPS2KTS = 3600.0f/1852.0f;
+    static const float KMH2MPS = 1/3.6f;
 
-  static const float FT2M = 0.3048f;
-  static const float M2FT = 1/FT2M;
+    static const float FT2M = 0.3048f;
+    static const float M2FT = 1/FT2M;
 
-  static const float LBS2N = 4.44822f;
-  static const float N2LB = 1/LBS2N;
-  static const float LBS2KG = 0.45359237f;
-  static const float KG2LBS = 1/LBS2KG;
-  static const float CM2GALS = 264.172037284f;
-  static const float HP2W = 745.700f;
-  static const float INHG2PA = 3386.389f;
-  static const float K2DEGF = 1.8f;
-  static const float K2DEGFOFFSET = -459.4f;
-  static const float CIN2CM = 1.6387064e-5f;
-  
-  static const float NM2FTLB = (1/(LBS2N*FT2M));
-  static const float SLUG2KG = 14.59390f;
+    static const float LBS2N = 4.44822f;
+    static const float N2LB = 1/LBS2N;
+    static const float LBS2KG = 0.45359237f;
+    static const float KG2LBS = 1/LBS2KG;
+    static const float CM2GALS = 264.172037284f;
+    static const float HP2W = 745.700f;
+    static const float INHG2PA = 3386.389f;
+    static const float K2DEGF = 1.8f;
+    static const float K2DEGFOFFSET = -459.4f;
+    static const float CIN2CM = 1.6387064e-5f;
     
-};
+    static const float NM2FTLB = (1/(LBS2N*FT2M));
+    static const float SLUG2KG = 14.59390f;
+
+    char* dup(const char* s);
+    bool eq(const char* a, const char* b);
+    
+}; //namespace yasim
 
 #endif // ifndef _YASIM_COMMON_HPP