diff --git a/src/FDM/YASim/FGFDM.cpp b/src/FDM/YASim/FGFDM.cpp
index e5e3f51f5..7fe64908b 100644
--- a/src/FDM/YASim/FGFDM.cpp
+++ b/src/FDM/YASim/FGFDM.cpp
@@ -800,37 +800,40 @@ void FGFDM::setOutputProperties(float dt)
 
 Wing* FGFDM::parseWing(XMLAttributes* a, const char* type, Version * version)
 {
-    Wing* w = new Wing(version);
-
     float defDihed = 0;
-    if(eq(type, "vstab"))
-	defDihed = 90;
-    else
-	w->setMirror(true);
+    bool mirror = true;
 
-    float pos[3];
-    pos[0] = attrf(a, "x");
-    pos[1] = attrf(a, "y");
-    pos[2] = attrf(a, "z");
-    w->setBase(pos);
-
-    w->setLength(attrf(a, "length"));
-    w->setChord(attrf(a, "chord"));
-    w->setSweep(attrf(a, "sweep", 0) * DEG2RAD);
-    w->setTaper(attrf(a, "taper", 1));
-    w->setDihedral(attrf(a, "dihedral", defDihed) * DEG2RAD);
-    
-    float camber = attrf(a, "camber", 0);
-    if (!version->isVersionOrNewer(Version::YASIM_VERSION_2017_2) && (camber == 0)) {
-      SG_LOG(SG_FLIGHT, SG_DEV_WARN, "YASIM warning: versions before 2017.2 are buggy for wings with camber=0");
+    if(eq(type, "vstab")) {
+      defDihed = 90;
+      mirror = false;
     }
-    w->setCamber(camber);
+
+    float base[3];
+    base[0] = attrf(a, "x");
+    base[1] = attrf(a, "y");
+    base[2] = attrf(a, "z");    
+
+    float length = attrf(a, "length");
+    float chord = attrf(a, "chord");
+    float sweep = attrf(a, "sweep", 0) * DEG2RAD;
+    float taper = attrf(a, "taper", 1);
+    float dihedral = attrf(a, "dihedral", defDihed) * DEG2RAD;
 
     // These come in with positive indicating positive AoA, but the
     // internals expect a rotation about the left-pointing Y axis, so
     // invert the sign.
-    w->setIncidence(attrf(a, "incidence", 0) * DEG2RAD * -1);
-    w->setTwist(attrf(a, "twist", 0) * DEG2RAD * -1);
+    float incidence = attrf(a, "incidence", 0) * DEG2RAD * -1;
+    float twist = attrf(a, "twist", 0) * DEG2RAD * -1;
+
+    float camber = attrf(a, "camber", 0);
+    if (!version->isVersionOrNewer(Version::YASIM_VERSION_2017_2) && (camber == 0)) {
+      SG_LOG(SG_FLIGHT, SG_DEV_WARN, "YASIM warning: versions before 2017.2 are buggy for wings with camber=0");
+    }
+    
+    Wing* w = new Wing(version, mirror, base, chord, length, 
+                       taper, sweep, dihedral, twist);
+    w->setIncidence(incidence);
+    w->setCamber(camber);
 
     // The 70% is a magic number that sorta kinda seems to match known
     // throttle settings to approach speed.
diff --git a/src/FDM/YASim/Wing.cpp b/src/FDM/YASim/Wing.cpp
index 793800381..8bb242749 100644
--- a/src/FDM/YASim/Wing.cpp
+++ b/src/FDM/YASim/Wing.cpp
@@ -4,10 +4,23 @@
 
 namespace yasim {
   
-Wing::Wing( Version * version ) :
-  _version(version)
+Wing::Wing(Version *ver, bool mirror, float* base, float chord, 
+        float length, float taper, float sweep, float dihedral, float twist) :
+    _version(ver),
+    _mirror(mirror),
+    _chord(chord),
+    _length(length),
+    _taper(taper),
+    _sweep(sweep),
+    _dihedral(dihedral),
+    _twist(twist)
 {
-
+    Math::set3(base, _base);
+    _meanChord = _chord*(_taper+1)*0.5f;
+    calculateWingCoordinateSystem();
+    calculateTip();
+    calculateSpan();
+    calculateMAC();
 }
 
 Wing::~Wing()
@@ -207,13 +220,6 @@ void Wing::compile()
         last = bounds[i];
     }
 
-    calculateWingCoordinateSystem();
-    calculateTip();
-    _meanChord = _chord*(_taper+1)*0.5f;
-    
-    calculateSpan();
-    calculateMAC();
-
     // Calculate a "nominal" segment length equal to an average chord,
     // normalized to lie within 0-1 over the length of the wing.
     float segLen = _meanChord / _length;
diff --git a/src/FDM/YASim/Wing.hpp b/src/FDM/YASim/Wing.hpp
index 6261e5b68..a76ea04a1 100644
--- a/src/FDM/YASim/Wing.hpp
+++ b/src/FDM/YASim/Wing.hpp
@@ -12,7 +12,8 @@ class Surface;
 // FIXME: need to handle "inverted" controls for mirrored wings.
 class Wing {
 public:
-    Wing( Version * version );
+    Wing(Version *ver, bool mirror, float* base, float chord, float length, 
+        float taper = 1, float sweep = 0, float dihedral = 0, float twist = 0);
     ~Wing();
 
     // Do we mirror ourselves about the XZ plane?
@@ -22,26 +23,20 @@ public:
     // Wing geometry in local coordinates:
     
     // base point of wing
-    void setBase(const float* base) { Math::set3(base, _base); }
     void getBase(float* base) const { Math::set3(_base, base); };
     // dist. ALONG wing (not span!)     
-    void setLength(float length) { _length = length; }
     float getLength() const { return _length; };
     // at base, measured along X axis
-    void setChord(float chord) { _chord = chord; }
     float getChord() const { return _chord; };
     // fraction of chord at wing tip, 0..1
-    void setTaper(float taper) { _taper = taper; }
     float getTaper() const { return _taper; };
     // radians
-    void setSweep(float sweep) { _sweep = sweep; }
     float getSweep() const { return _sweep; };
     // radians, positive is "up"
     void setDihedral(float dihedral) { _dihedral = dihedral; }
     float getDihedral() const { return _dihedral; };
     
     void setIncidence(float incidence);
-    void setTwist(float angle) { _twist = angle; }
     
     
     // parameters for stall curve
@@ -110,11 +105,11 @@ private:
     Vector _slatSurfs;
     Vector _spoilerSurfs;
 
+    Version * _version;
     bool _mirror {false};
-
     float _base[3] {0,0,0};
-    float _length {0};
     float _chord {0};
+    float _length {0};
     float _taper {1};
     float _sweep {0};
     float _dihedral {0};
@@ -161,8 +156,6 @@ private:
     float _slatEnd {0};
     float _slatAoA {0};
     float _slatDrag {0};
-
-    Version * _version;
 };
 
 }; // namespace yasim