diff --git a/src/blackgui/models/aircraftcategorytreemodel.cpp b/src/blackgui/models/aircraftcategorytreemodel.cpp
index e459748cc..682326659 100644
--- a/src/blackgui/models/aircraftcategorytreemodel.cpp
+++ b/src/blackgui/models/aircraftcategorytreemodel.cpp
@@ -12,6 +12,7 @@
 #include "blackgui/models/columns.h"
 #include "blackmisc/compare.h"
 #include "blackmisc/icon.h"
+#include "blackmisc/threadutils.h"
 #include "blackmisc/variant.h"
 #include "blackmisc/propertyindex.h"
 
@@ -40,6 +41,8 @@ namespace BlackGui
 
         void CAircraftCategoryTreeModel::updateContainer(const CAircraftCategoryList &categories)
         {
+            Q_ASSERT_X(CThreadUtils::isCurrentThreadObjectThread(this), Q_FUNC_INFO, "Wrong thread");
+
             this->clear();
             if (categories.isEmpty())  { return; }
 
@@ -73,6 +76,8 @@ namespace BlackGui
 
                 // add all items
                 if (categoryRow.isEmpty()) { continue; }
+
+                QStandardItem *parent = categoryRow.first();
                 if (category.isFirstLevel())
                 {
                     this->invisibleRootItem()->appendRow(categoryRow);
@@ -83,9 +88,7 @@ namespace BlackGui
                     Q_ASSERT_X(items[p], Q_FUNC_INFO, "No parent item");
                     items[p]->appendRow(categoryRow);
                 }
-
-                Q_ASSERT_X(!categoryRow.isEmpty(), Q_FUNC_INFO, "Category row is empty");
-                items.insert(category.getDepth(), categoryRow.front());
+                items.insert(category.getDepth(), parent);
             }
         }
 
diff --git a/src/blackgui/views/aircraftcategorytreeview.cpp b/src/blackgui/views/aircraftcategorytreeview.cpp
index c1f8e5a28..b40e7e63a 100644
--- a/src/blackgui/views/aircraftcategorytreeview.cpp
+++ b/src/blackgui/views/aircraftcategorytreeview.cpp
@@ -32,14 +32,18 @@ namespace BlackGui
             this->setModel(new CAircraftCategoryTreeModel(this));
             this->setContextMenuPolicy(Qt::CustomContextMenu);
             connect(this, &CAircraftCategoryTreeView::customContextMenuRequested, this, &CAircraftCategoryTreeView::customMenu);
-            connect(this, &CAircraftCategoryTreeView::expanded, this, &CAircraftCategoryTreeView::onExpanded);
+            connect(this, &CAircraftCategoryTreeView::expanded, this, &CAircraftCategoryTreeView::onExpanded, Qt::QueuedConnection);
         }
 
         void CAircraftCategoryTreeView::updateContainer(const CAircraftCategoryList &categories)
         {
             if (!this->categoryModel()) { return; }
             this->categoryModel()->updateContainer(categories);
-            if (!this->isEmpty()) { this->expandAll(); }
+
+            //! \fixme 2019-02 workaround for HEAP: Free Heap block 000001AB439BFFF0 modified at 000001AB439C00BC after it was freed
+            // using Qt::QueuedConnection seems to fix for expand all
+            // also this->expandToDepth(0) seems to work
+            this->expandAll();
         }
 
         void CAircraftCategoryTreeView::clear()
@@ -86,18 +90,12 @@ namespace BlackGui
         CAircraftCategory CAircraftCategoryTreeView::selectedObject() const
         {
             const QModelIndex index = this->currentIndex();
-            const QVariant data = this->model()->data(index.siblingAtColumn(0)); // supposed to be the callsign
+            const QVariant data = this->model()->data(index.siblingAtColumn(0));
             const CAircraftCategoryTreeModel *model = this->categoryModel();
             if (!model) { return CAircraftCategory(); }
             return model->container().frontOrDefault();
         }
 
-        QString CAircraftCategoryTreeView::suffixForIndex(const QModelIndex &index)
-        {
-            const QVariant data = this->model()->data(index); // supposed to be the suffix
-            return data.toString();
-        }
-
         void CAircraftCategoryTreeView::onExpanded(const QModelIndex &index)
         {
             Q_UNUSED(index);
diff --git a/src/blackgui/views/aircraftcategorytreeview.h b/src/blackgui/views/aircraftcategorytreeview.h
index 10af2265f..4d9d404cd 100644
--- a/src/blackgui/views/aircraftcategorytreeview.h
+++ b/src/blackgui/views/aircraftcategorytreeview.h
@@ -69,9 +69,6 @@ namespace BlackGui
             //! The selected object
             BlackMisc::Aviation::CAircraftCategory selectedObject() const;
 
-            //! Suffix for index
-            QString suffixForIndex(const QModelIndex &index);
-
             //! Expanded
             void onExpanded(const QModelIndex &index);