diff --git a/simgear/scene/tgdb/VPBTechnique.cxx b/simgear/scene/tgdb/VPBTechnique.cxx
index 7cae7154..107d12db 100644
--- a/simgear/scene/tgdb/VPBTechnique.cxx
+++ b/simgear/scene/tgdb/VPBTechnique.cxx
@@ -2251,6 +2251,13 @@ void VPBTechnique::removeElevationConstraint(osg::ref_ptr<osg::Node> constraint)
     _constraintGroup->removeChild(constraint.get()); 
 }
 
+void VPBTechnique::clearElevationConstraints()
+{
+    const std::lock_guard<std::mutex> lock(VPBTechnique::_constraint_mutex); // Lock the _constraintGroup for this scope
+    _constraintGroup = new osg::Group();
+}
+
+
 // Check a given vertex against any elevation constraints  E.g. to ensure the terrain mesh doesn't
 // poke through any airport meshes.  If such a constraint exists, the function will return a replacement
 // vertex displaces such that it lies 1m below the contraint relative to the passed in origin.  
diff --git a/simgear/scene/tgdb/VPBTechnique.hxx b/simgear/scene/tgdb/VPBTechnique.hxx
index 0e24cc26..9053f2a4 100644
--- a/simgear/scene/tgdb/VPBTechnique.hxx
+++ b/simgear/scene/tgdb/VPBTechnique.hxx
@@ -95,6 +95,7 @@ class VPBTechnique : public TerrainTechnique
         static void addElevationConstraint(osg::ref_ptr<osg::Node> constraint, osg::Group* terrain);
         static void removeElevationConstraint(osg::ref_ptr<osg::Node> constraint);
         static osg::Vec3d checkAgainstElevationConstraints(osg::Vec3d origin, osg::Vec3d vertex, float vertex_gap);
+        static void clearElevationConstraints();
 
         // LineFeatures and AreaFeatures are draped over the underlying mesh.
         static void addLineFeatureList(SGBucket bucket, LineFeatureBinList roadList);
@@ -183,7 +184,7 @@ class VPBTechnique : public TerrainTechnique
         osg::ref_ptr<osg::Uniform>          _filterMatrixUniform;
         osg::ref_ptr<SGReaderWriterOptions> _options;
 
-        inline static osg::ref_ptr<osg::Group>  _constraintGroup = new osg::Group();;
+        inline static osg::ref_ptr<osg::Group>  _constraintGroup = new osg::Group();
         inline static std::mutex _constraint_mutex;  // protects the _constraintGroup;
 
         typedef std::pair<SGBucket, LineFeatureBinList> BucketLineFeatureBinList;
@@ -198,10 +199,8 @@ class VPBTechnique : public TerrainTechnique
 
         inline static std::list<BucketCoastlineBinList>  _coastFeatureLists;
         inline static std::mutex _coastFeatureLists_mutex;  // protects the _areaFeatureLists;
-
 };
 
 };
 
-
 #endif