diff --git a/src/AIModel/AIBase.cxx b/src/AIModel/AIBase.cxx
index 230837621..e307a1d83 100644
--- a/src/AIModel/AIBase.cxx
+++ b/src/AIModel/AIBase.cxx
@@ -145,7 +145,7 @@ FGAIBase::~FGAIBase() {
             model_removed->setStringValue(props->getPath());
     }
 
-    if (_refID != 0 && _refID !=  1) {
+    if (_fx && _refID != 0 && _refID !=  1) {
         SGSoundMgr *smgr = globals->get_soundmgr();
         stringstream name; 
         name <<  "aifx:";
@@ -153,7 +153,8 @@ FGAIBase::~FGAIBase() {
         smgr->remove(name.str());
     }
 
-    delete fp;
+    if (fp)
+        delete fp;
     fp = 0;
 }
 
diff --git a/src/AIModel/AIBase.hxx b/src/AIModel/AIBase.hxx
index f09a96e00..b4815c41a 100644
--- a/src/AIModel/AIBase.hxx
+++ b/src/AIModel/AIBase.hxx
@@ -230,7 +230,7 @@ private:
     bool _initialized;
     osg::ref_ptr<osg::LOD> _model; //The 3D model LOD object
 
-    FGAIModelData* _aimodel;
+    osg::ref_ptr<FGAIModelData> _aimodel;
 
     string _fxpath;
     SGSharedPtr<FGFX>  _fx;