diff --git a/src/FDM/YASim/Launchbar.cpp b/src/FDM/YASim/Launchbar.cpp
index 756e9a034..26d2ab58e 100644
--- a/src/FDM/YASim/Launchbar.cpp
+++ b/src/FDM/YASim/Launchbar.cpp
@@ -7,8 +7,11 @@
 namespace yasim {
 
   static const float YASIM_PI2 = 3.14159265358979323846f/2;
-  static const float YASIM_PI = 3.14159265358979323846f;
+
+#if 0 // unused, supressing compiler warning
   static const float RAD2DEG = 180/YASIM_PI;
+  static const float YASIM_PI = 3.14159265358979323846f;
+#endif
 
 Launchbar::Launchbar()
 {
diff --git a/src/FDM/YASim/Turbulence.cpp b/src/FDM/YASim/Turbulence.cpp
index 1b4048d1e..d644af28a 100644
--- a/src/FDM/YASim/Turbulence.cpp
+++ b/src/FDM/YASim/Turbulence.cpp
@@ -27,8 +27,10 @@ const double MAGNITUDE_EXP = 2.0;
 // 2^(MEANINGFUL_GENS-1).
 const int MEANINGFUL_GENS = 7;
 
+#if 0 // unused, supressing compiler warning
 static const float FT2M = 0.3048;
-
+#endif
+    
 // 8 x 32 s-box used by hashrand.  Read out of /dev/random on my Linux
 // box; not analyzed for linearity or coverage issues.
 static unsigned int SBOX[] = {
diff --git a/src/FDM/YASim/YASim.cxx b/src/FDM/YASim/YASim.cxx
index d82d14398..07163676a 100644
--- a/src/FDM/YASim/YASim.cxx
+++ b/src/FDM/YASim/YASim.cxx
@@ -37,15 +37,18 @@ using std::string;
 static const float YASIM_PI = 3.14159265358979323846;
 static const float RAD2DEG = 180/YASIM_PI;
 static const float PI2 = YASIM_PI*2;
-static const float RAD2RPM = 9.54929658551;
 static const float M2FT = 3.2808399;
 static const float FT2M = 0.3048;
 static const float MPS2KTS = 3600.0/1852.0;
+static const float INHG2PA = 3386.389;
+static const float SLUG2KG = 14.59390;
+
+#if 0 // unused constant values
+static const float RAD2RPM = 9.54929658551;
 static const float CM2GALS = 264.172037284; // gallons/cubic meter
 static const float KG2LBS = 2.20462262185;
 static const float W2HP = 1.3416e-3;
-static const float INHG2PA = 3386.389;
-static const float SLUG2KG = 14.59390;
+#endif
 
 YASim::YASim(double dt) :
     _simTime(0)