Index: src/economy.cpp
===================================================================
--- src/economy.cpp	(revision 14286)
+++ src/economy.cpp	(working copy)
@@ -472,6 +472,7 @@
 
 	_current_player = old;
 
+	UpdateNobodysStations();
 	MarkWholeScreenDirty();
 }
 
Index: src/openttd.cpp
===================================================================
--- src/openttd.cpp	(revision 14286)
+++ src/openttd.cpp	(working copy)
@@ -820,6 +820,7 @@
 	_current_player = _local_player;
 	DoCommandP(0, (_settings_client.gui.autorenew << 15 ) | (_settings_client.gui.autorenew_months << 16) | 4, _settings_client.gui.autorenew_money, NULL, CMD_SET_AUTOREPLACE);
 
+	UpdateNobodysStations();
 	MarkWholeScreenDirty();
 }
 
@@ -934,6 +935,7 @@
 				}
 #endif /* ENABLE_NETWORK */
 			}
+			UpdateNobodysStations();
 			break;
 		}
 
@@ -950,6 +952,7 @@
 			SetLocalPlayer(OWNER_NONE);
 
 			GenerateWorld(GW_HEIGHTMAP, 1 << _settings_game.game_creation.map_x, 1 << _settings_game.game_creation.map_y);
+			UpdateNobodysStations();
 			MarkWholeScreenDirty();
 			break;
 
@@ -962,6 +965,7 @@
 				SetDParamStr(1, GetSaveLoadErrorString());
 				ShowErrorMessage(INVALID_STRING_ID, STR_012D, 0, 0);
 			}
+			UpdateNobodysStations();
 			break;
 		}
 
Index: src/station_func.h
===================================================================
--- src/station_func.h	(revision 14286)
+++ src/station_func.h	(working copy)
@@ -49,4 +49,6 @@
 
 void UpdateAirportsNoise();
 
+void UpdateNobodysStations();
+
 #endif /* STATION_FUNC_H */
Index: src/station.cpp
===================================================================
--- src/station.cpp	(revision 14286)
+++ src/station.cpp	(working copy)
@@ -508,3 +508,56 @@
 
 	return NULL;
 }
+
+/**
+ * Update the nobody owned airports (oilfields),
+ * and set them as free if they are not being used.
+ */
+void UpdateNobodysStations()
+{
+	Vehicle *v;
+	Station *st;
+	TileIndex *occupied_tiles = MallocT<TileIndex>(1);
+	int i, count = 0;
+	bool is_used;
+
+	/* Loop through all the landed airplanes and keep their
+	 * positions in mind */
+	FOR_ALL_VEHICLES(v)
+	{
+		if (v->type == VEH_AIRCRAFT && v->tile != 0)
+		{
+			occupied_tiles = ReallocT(occupied_tiles, ++count);
+			occupied_tiles[count - 1] = v->tile;
+		}
+	}
+
+	/* Loop through airports of nobody owned stations (typically oilfields),
+	 * and find ones where aren't any aircrafts landed */
+	FOR_ALL_STATIONS(st)
+	{
+		if (st->owner == OWNER_NONE && st->airport_tile != 0)
+		{
+			is_used = false;
+			for (i=0; i<count; i++)
+			{
+				if (occupied_tiles[i] == st->airport_tile)
+				{
+					is_used = true;
+					break;
+				}
+			}
+
+			if (!is_used)
+			{
+				st->airport_flags = NOTHING_block;
+			}
+		}
+	}
+
+	free(v);
+	free(st);
+	free(occupied_tiles);
+
+	return;
+}