diff --git a/src/AIModel/AIAircraft.cxx b/src/AIModel/AIAircraft.cxx
index 2e465eea0..00bad5ebd 100644
--- a/src/AIModel/AIAircraft.cxx
+++ b/src/AIModel/AIAircraft.cxx
@@ -926,48 +926,50 @@ void FGAIAircraft::getGroundElev(double dt) {
   //aip.getSGLocation()->set_tile_center(Point3D(buck.get_center_lon(), buck.get_center_lat(), 0.0));
   
   // Only do the proper hitlist stuff if we are within visible range of the viewer.
-  double visibility_meters = fgGetDouble("/environment/visibility-m");	
- 
-
-  FGViewer* vw = globals->get_current_view();
-  double 
-    course, 
-    distance;
-
-  //Point3D currView(vw->getLongitude_deg(), 
-  //		   vw->getLatitude_deg(), 0.0);
-  SGWayPoint current  (pos.lon(),
-		       pos.lat(),
-		       0);
-  SGWayPoint view (   vw->getLongitude_deg(),
-		      vw->getLatitude_deg(),
-		      0);
-  view.CourseAndDistance(current, &course, &distance);
-  if(distance > visibility_meters) {
-    //aip.getSGLocation()->set_cur_elev_m(aptElev);
-    return;
-  }
-    
-  // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
-  double range = 500.0;
-  if (!globals->get_tile_mgr()->scenery_available(pos.lat(), pos.lon(), range))
-  {
-    // Try to shedule tiles for that position.
-    globals->get_tile_mgr()->update( aip.getSGLocation(), range );
-  }
-
-  // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
-  double alt;
-  if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
-                                              20000.0, alt))
-      tgt_altitude = alt * SG_METER_TO_FEET; 
-  //cerr << "Target altitude : " << tgt_altitude << endl;
-  // if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
-  //                                            20000.0, alt))
-  //    tgt_altitude = alt * SG_METER_TO_FEET;
-  //cerr << "Target altitude : " << tgt_altitude << endl;
+   if (!invisible) {
+     double visibility_meters = fgGetDouble("/environment/visibility-m");	
+     
+     
+     FGViewer* vw = globals->get_current_view();
+     double 
+       course, 
+       distance;
+     
+     //Point3D currView(vw->getLongitude_deg(), 
+     //		   vw->getLatitude_deg(), 0.0);
+     SGWayPoint current  (pos.lon(),
+			  pos.lat(),
+			  0);
+     SGWayPoint view (   vw->getLongitude_deg(),
+			 vw->getLatitude_deg(),
+			 0);
+     view.CourseAndDistance(current, &course, &distance);
+     if(distance > visibility_meters) {
+       //aip.getSGLocation()->set_cur_elev_m(aptElev);
+       return;
+     }
+     
+     // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
+     double range = 500.0;
+     if (!globals->get_tile_mgr()->scenery_available(pos.lat(), pos.lon(), range))
+       {
+	 // Try to shedule tiles for that position.
+	 globals->get_tile_mgr()->update( aip.getSGLocation(), range );
+       }
+     
+     // FIXME: make sure the pos.lat/pos.lon values are in degrees ...
+     double alt;
+     if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
+						 20000.0, alt))
+       tgt_altitude = alt * SG_METER_TO_FEET; 
+     //cerr << "Target altitude : " << tgt_altitude << endl;
+     // if (globals->get_scenery()->get_elevation_m(pos.lat(), pos.lon(),
+     //                                            20000.0, alt))
+     //    tgt_altitude = alt * SG_METER_TO_FEET;
+     //cerr << "Target altitude : " << tgt_altitude << endl;
+   }
 }
-
+   
 void FGAIAircraft::doGroundAltitude()
 {
   if (fabs(altitude - (tgt_altitude+groundOffset)) > 1000.0)
diff --git a/src/Traffic/Schedule.cxx b/src/Traffic/Schedule.cxx
index a33b45d11..9ac106e40 100644
--- a/src/Traffic/Schedule.cxx
+++ b/src/Traffic/Schedule.cxx
@@ -366,33 +366,40 @@ bool FGAISchedule::update(time_t now)
 	      //	  alt = dep->_elevation+19;
 	      //	}
 
-	      // Fixme: A non-existent model path results in an
-	      // abort, due to an unhandled exeption, in fg main loop.
-              FGAIAircraft *aircraft = new FGAIAircraft(this);
-              aircraft->setPerformance(m_class); //"jet_transport";
-	      aircraft->setCompany(airline); //i->getAirline();
-	      aircraft->setAcType(acType); //i->getAcType();
-              aircraft->setPath(modelPath.c_str());
-              aircraft->setFlightPlan(flightPlanName);
-              aircraft->setLatitude(lat);
-              aircraft->setLongitude(lon);
-              aircraft->setAltitude(i->getCruiseAlt()*100); // convert from FL to feet
-              aircraft->setSpeed(speed);
-              aircraft->setBank(0);
-              aircraft->SetFlightPlan(new FGAIFlightPlan(modelPath, courseToDest, i->getDepartureTime(), dep, 
-                                                         arr,true, radius, i->getCruiseAlt()*100, lat, lon, speed, flightType, acType, airline));
-              aimgr->attach(aircraft);
-	      
-
-	      AIManagerRef = aircraft->getID();
-	      //cerr << "Class: " << m_class << ". acType: " << acType << ". Airline: " << airline << ". Speed = " << speed << ". From " << dep->getId() << " to " << arr->getId() << ". Time Fraction = " << (remainingTimeEnroute/(double) totalTimeEnroute) << endl;
-	      //cerr << "Latitude : " << lat << ". Longitude : " << lon << endl;
-	      //cerr << "Dep      : " << dep->getLatitude()<< ", "<< dep->getLongitude() << endl;
-	      //cerr << "Arr      : " << arr->getLatitude()<< ", "<< arr->getLongitude() << endl;
-	      //cerr << "Time remaining = " << (remainingTimeEnroute/3600.0) << endl;
-	      //cerr << "Total time     = " << (totalTimeEnroute/3600.0) << endl;
-	      //cerr << "Distance remaining = " << distanceToDest*SG_METER_TO_NM << endl;
-	      
+	      // Only allow traffic to be created when the model path exists
+	      SGPath mp(globals->get_fg_root());
+	      mp.append(modelPath);
+	      if (mp.exists()) 
+	      {
+		  FGAIAircraft *aircraft = new FGAIAircraft(this);
+		  aircraft->setPerformance(m_class); //"jet_transport";
+		  aircraft->setCompany(airline); //i->getAirline();
+		  aircraft->setAcType(acType); //i->getAcType();
+		  aircraft->setPath(modelPath.c_str());
+		  aircraft->setFlightPlan(flightPlanName);
+		  aircraft->setLatitude(lat);
+		  aircraft->setLongitude(lon);
+		  aircraft->setAltitude(i->getCruiseAlt()*100); // convert from FL to feet
+		  aircraft->setSpeed(speed);
+		  aircraft->setBank(0);
+		  aircraft->SetFlightPlan(new FGAIFlightPlan(modelPath, courseToDest, i->getDepartureTime(), dep, 
+							     arr,true, radius, i->getCruiseAlt()*100, lat, lon, speed, flightType, acType, airline));
+		  aimgr->attach(aircraft);
+		  
+		  
+		  AIManagerRef = aircraft->getID();
+		  //cerr << "Class: " << m_class << ". acType: " << acType << ". Airline: " << airline << ". Speed = " << speed << ". From " << dep->getId() << " to " << arr->getId() << ". Time Fraction = " << (remainingTimeEnroute/(double) totalTimeEnroute) << endl;
+		  //cerr << "Latitude : " << lat << ". Longitude : " << lon << endl;
+		  //cerr << "Dep      : " << dep->getLatitude()<< ", "<< dep->getLongitude() << endl;
+		  //cerr << "Arr      : " << arr->getLatitude()<< ", "<< arr->getLongitude() << endl;
+		  //cerr << "Time remaining = " << (remainingTimeEnroute/3600.0) << endl;
+		  //cerr << "Total time     = " << (totalTimeEnroute/3600.0) << endl;
+		  //cerr << "Distance remaining = " << distanceToDest*SG_METER_TO_NM << endl;
+		  }
+	      else
+		{
+		  SG_LOG(SG_INPUT, SG_WARN, "TrafficManager: Could not load model " << mp.str());
+		}
 	    }
 	  return true;
     }