diff --git a/src/blackmisc/aviation/aircraftcategory.cpp b/src/blackmisc/aviation/aircraftcategory.cpp
index 3f71c619c..7a505ae36 100644
--- a/src/blackmisc/aviation/aircraftcategory.cpp
+++ b/src/blackmisc/aviation/aircraftcategory.cpp
@@ -79,14 +79,31 @@ namespace BlackMisc
 
         void CAircraftCategory::setLevel(int l1, int l2, int l3)
         {
-            m_level[0] = l1;
-            m_level[1] = l2;
-            m_level[2] = l3;
+            m_l1 = l1;
+            m_l2 = l2;
+            m_l3 = l3;
+        }
+
+        bool CAircraftCategory::isFirstLevel() const
+        {
+            return (m_l3 == 0 && m_l2 == 0 && m_l1 > 0);
+        }
+
+        int CAircraftCategory::getDepth() const
+        {
+            if (this->isFirstLevel()) { return 1; }
+            if (m_l3 == 0 && m_l2 > 0 && m_l1 > 0) { return 2; }
+            return 3;
         }
 
         QString CAircraftCategory::getLevelString() const
         {
-            return QStringLiteral("%1.%2.%3").arg(m_level[0]).arg(m_level[1]).arg(m_level[2]);
+            return QStringLiteral("%1.%2.%3").arg(m_l1).arg(m_l2).arg(m_l3);
+        }
+
+        QString CAircraftCategory::getLevelAndName() const
+        {
+            return QStringLiteral("%1 %2").arg(this->getLevelString(), this->getName());
         }
 
         bool CAircraftCategory::matchesPath(const QString &path, Qt::CaseSensitivity cs)
@@ -132,9 +149,10 @@ namespace BlackMisc
             switch (i)
             {
             case IndexName:        return m_name.compare(compareValue.getName(), Qt::CaseInsensitive);
-            case IndexPath:        return m_description.compare(compareValue.getPath(), Qt::CaseInsensitive);
-            case IndexDescription: return m_path.compare(compareValue.getDescription(), Qt::CaseInsensitive);
+            case IndexPath:        return m_path.compare(compareValue.getPath(), Qt::CaseInsensitive);
+            case IndexDescription: return m_description.compare(compareValue.getDescription(), Qt::CaseInsensitive);
             case IndexAssignable:  return Compare::compare(this->isAssignable(), compareValue.isAssignable());
+            case IndexLevelString: return this->compareByLevel(compareValue);
             default: return CValueObject::comparePropertyByIndex(index, *this);
             }
             Q_ASSERT_X(false, Q_FUNC_INFO, "No comparison");
@@ -156,5 +174,16 @@ namespace BlackMisc
             cat.setKeyVersionTimestampFromDatabaseJson(json, prefix);
             return cat;
         }
+
+        int CAircraftCategory::compareByLevel(const CAircraftCategory &other) const
+        {
+            // any faster or better way to compare can be used here
+            int c = Compare::compare(m_l1, other.m_l1);
+            if (c != 0) { return c; }
+            c = Compare::compare(m_l2, other.m_l2);
+            if (c != 0) { return c; }
+            c = Compare::compare(m_l3, other.m_l3);
+            return c;
+        }
     } // namespace
 } // namespace
diff --git a/src/blackmisc/aviation/aircraftcategory.h b/src/blackmisc/aviation/aircraftcategory.h
index f4120e2d4..cbc28edf7 100644
--- a/src/blackmisc/aviation/aircraftcategory.h
+++ b/src/blackmisc/aviation/aircraftcategory.h
@@ -38,7 +38,7 @@ namespace BlackMisc
             //! Properties by index
             enum ColumnIndex
             {
-                IndexName = BlackMisc::CPropertyIndex::GlobalIndexCAircraftCategory,
+                IndexName = CPropertyIndex::GlobalIndexCAircraftCategory,
                 IndexDescription,
                 IndexLevelString,
                 IndexPath,
@@ -78,9 +78,21 @@ namespace BlackMisc
             //! Level
             void setLevel(int l1, int l2, int l3);
 
+            //! First level
+            int getFirstLevel() const { return m_l1; }
+
+            //! First level
+            bool isFirstLevel() const;
+
+            //! Depth 1, 2, 3
+            int getDepth() const;
+
             //! Level string
             QString getLevelString() const;
 
+            //! Level and name
+            QString getLevelAndName() const;
+
             //! Matching path?
             bool matchesPath(const QString &path, Qt::CaseSensitivity cs);
 
@@ -108,6 +120,9 @@ namespace BlackMisc
             //! Null ICAO?
             bool isNull() const;
 
+            //! Level compare
+            int compareByLevel(const CAircraftCategory &other) const;
+
             //! NULL object
             static const CAircraftCategory &null();
 
@@ -119,13 +134,17 @@ namespace BlackMisc
             QString m_description;    //!< description
             QString m_path;           //!< path
             bool m_assignable = true; //!< can assign to category?
-            int m_level[3] = { 0, 0, 0};
+            int m_l1 = 0;
+            int m_l2 = 0;
+            int m_l3 = 0;
             BLACK_METACLASS(
                 CAircraftCategory,
                 BLACK_METAMEMBER(dbKey),
                 BLACK_METAMEMBER(timestampMSecsSinceEpoch),
                 BLACK_METAMEMBER(name),
-                // BLACK_METAMEMBER(level),
+                BLACK_METAMEMBER(l1),
+                BLACK_METAMEMBER(l2),
+                BLACK_METAMEMBER(l3),
                 BLACK_METAMEMBER(description),
                 BLACK_METAMEMBER(path),
                 BLACK_METAMEMBER(assignable)
diff --git a/src/blackmisc/aviation/aircraftcategorylist.cpp b/src/blackmisc/aviation/aircraftcategorylist.cpp
index 71499300a..675c0964b 100644
--- a/src/blackmisc/aviation/aircraftcategorylist.cpp
+++ b/src/blackmisc/aviation/aircraftcategorylist.cpp
@@ -33,20 +33,66 @@ namespace BlackMisc
             });
         }
 
-        void CAircraftCategoryList::sortByRank()
+        void CAircraftCategoryList::sortByPath()
         {
             this->sortBy(&CAircraftCategory::getPath);
         }
 
+        void CAircraftCategoryList::sortByLevel()
+        {
+            this->sort([](const CAircraftCategory & a, const CAircraftCategory & b)
+            {
+                const int c = a.compareByLevel(b);
+                return c < 0;
+            });
+        }
+
+        QSet<QString> CAircraftCategoryList::getLevelStrings() const
+        {
+            QSet<QString> levels;
+            for (const CAircraftCategory &category : *this)
+            {
+                levels.insert(category.getLevelString());
+            }
+            return levels;
+        }
+
+        QList<int> CAircraftCategoryList::getFirstLevels() const
+        {
+            QSet<int> levels;
+            for (const CAircraftCategory &category : *this)
+            {
+                levels.insert(category.getFirstLevel());
+            }
+            QList<int> ll = levels.toList();
+            std::sort(ll.begin(), ll.end());
+            return ll;
+        }
+
+        CAircraftCategoryList CAircraftCategoryList::findByFirstLevel(int level) const
+        {
+            CAircraftCategoryList categories;
+            for (const CAircraftCategory &category : *this)
+            {
+                if (category.getFirstLevel() != level) { continue; }
+            }
+            return categories;
+        }
+
+        CAircraftCategoryList CAircraftCategoryList::findFirstLevels() const
+        {
+            return this->findBy(&CAircraftCategory::isFirstLevel, true);
+        }
+
         CAircraftCategoryList CAircraftCategoryList::fromDatabaseJson(const QJsonArray &array)
         {
-            CAircraftCategoryList codes;
+            CAircraftCategoryList categories;
             for (const QJsonValue &value : array)
             {
                 const CAircraftCategory category(CAircraftCategory::fromDatabaseJson(value.toObject()));
-                codes.push_back(category);
+                categories.push_back(category);
             }
-            return codes;
+            return categories;
         }
 
     } // namespace
diff --git a/src/blackmisc/aviation/aircraftcategorylist.h b/src/blackmisc/aviation/aircraftcategorylist.h
index 65ad24815..e77705755 100644
--- a/src/blackmisc/aviation/aircraftcategorylist.h
+++ b/src/blackmisc/aviation/aircraftcategorylist.h
@@ -21,7 +21,7 @@
 
 #include <QJsonArray>
 #include <QMetaType>
-#include <QStringList>
+#include <QSet>
 #include <tuple>
 
 namespace BlackMisc
@@ -47,7 +47,22 @@ namespace BlackMisc
             CAircraftCategoryList findByName(const QString &name, Qt::CaseSensitivity cs = Qt::CaseInsensitive) const;
 
             //! Sort by path
-            void sortByRank();
+            void sortByPath();
+
+            //! Sort by level
+            void sortByLevel();
+
+            //! Get all level strings
+            QSet<QString> getLevelStrings() const;
+
+            //! All levels sorted
+            QList<int> getFirstLevels() const;
+
+            //! Find by first level
+            CAircraftCategoryList findByFirstLevel(int level) const;
+
+            //! Find first levels
+            CAircraftCategoryList findFirstLevels() const;
 
             //! From our database JSON format
             static CAircraftCategoryList fromDatabaseJson(const QJsonArray &array);