diff --git a/src/blackcore/modelsetbuilder.cpp b/src/blackcore/modelsetbuilder.cpp
index d042ab722..e99fed222 100644
--- a/src/blackcore/modelsetbuilder.cpp
+++ b/src/blackcore/modelsetbuilder.cpp
@@ -52,7 +52,7 @@ namespace BlackCore
         else if (oprions.testFlag(OnlyDbIcaoCodes))
         {
             Q_ASSERT_X(sApp->hasWebDataServices(), Q_FUNC_INFO, "No web data services");
-            const QStringList designators(sApp->getWebDataServices()->getAircraftIcaoCodes().allIcaoCodes());
+            const QSet<QString> designators(sApp->getWebDataServices()->getAircraftIcaoCodes().allIcaoCodes());
             modelSet = modelSet.findWithAircraftDesignator(designators);
         }
         else
diff --git a/src/blackgui/components/flightplancomponent.cpp b/src/blackgui/components/flightplancomponent.cpp
index 6833853c9..c12bf96cb 100644
--- a/src/blackgui/components/flightplancomponent.cpp
+++ b/src/blackgui/components/flightplancomponent.cpp
@@ -551,7 +551,7 @@ namespace BlackGui
         void CFlightPlanComponent::initCompleters()
         {
             if (!sGui || !sGui->getWebDataServices()) { return; }
-            const QStringList aircraft = sGui->getWebDataServices()->getAircraftIcaoCodes().allIcaoCodes();
+            const QStringList aircraft(sGui->getWebDataServices()->getAircraftIcaoCodes().allIcaoCodes().toList());
             ui->le_AircraftType->setCompleter(new QCompleter(aircraft, this));
 
             const QStringList airports = sGui->getWebDataServices()->getAirports().allIcaoCodes(true);
diff --git a/src/blackmisc/aviation/aircrafticaocodelist.cpp b/src/blackmisc/aviation/aircrafticaocodelist.cpp
index 3020488c6..a0af82388 100644
--- a/src/blackmisc/aviation/aircrafticaocodelist.cpp
+++ b/src/blackmisc/aviation/aircrafticaocodelist.cpp
@@ -180,7 +180,7 @@ namespace BlackMisc
             return c;
         }
 
-        QStringList CAircraftIcaoCodeList::allIcaoCodes(bool onlyKnownDesignators) const
+        QSet<QString> CAircraftIcaoCodeList::allIcaoCodes(bool onlyKnownDesignators) const
         {
             QSet<QString> c;
             for (const CAircraftIcaoCode &icao : *this)
@@ -189,18 +189,18 @@ namespace BlackMisc
                 const QString d(icao.getDesignator());
                 c.insert(d);
             }
-            return c.toList();
+            return c;
         }
 
-        QStringList CAircraftIcaoCodeList::allManufacturers(bool onlyKnownDesignators) const
+        QSet<QString> CAircraftIcaoCodeList::allManufacturers(bool onlyKnownDesignators) const
         {
-            QStringList c;
+            QSet<QString> c;
             for (const CAircraftIcaoCode &icao : *this)
             {
                 if (onlyKnownDesignators && !icao.hasKnownDesignator()) { continue; }
                 const QString m(icao.getManufacturer());
-                if (m.isEmpty() || c.contains(m)) { continue; }
-                c.append(m);
+                if (m.isEmpty()) { continue; }
+                c.insert(m); // checks if already contains m
             }
             return c;
         }
diff --git a/src/blackmisc/aviation/aircrafticaocodelist.h b/src/blackmisc/aviation/aircrafticaocodelist.h
index 6b154b432..0578f5867 100644
--- a/src/blackmisc/aviation/aircrafticaocodelist.h
+++ b/src/blackmisc/aviation/aircrafticaocodelist.h
@@ -92,10 +92,10 @@ namespace BlackMisc
             QStringList toCompleterStrings(bool withIataCodes = false, bool withFamily = false, bool sort = true) const;
 
             //! All ICAO codes, no duplicates
-            QStringList allIcaoCodes(bool noUnspecified = true) const;
+            QSet<QString> allIcaoCodes(bool noUnspecified = true) const;
 
             //! All manufacturers
-            QStringList allManufacturers(bool onlyKnownDesignators = true) const;
+            QSet<QString> allManufacturers(bool onlyKnownDesignators = true) const;
 
             //! From our database JSON format
             static CAircraftIcaoCodeList fromDatabaseJson(const QJsonArray &array, bool ignoreIncomplete = true);
diff --git a/src/blackmisc/simulation/aircraftmodellist.cpp b/src/blackmisc/simulation/aircraftmodellist.cpp
index 1d2249008..c75f02cd8 100644
--- a/src/blackmisc/simulation/aircraftmodellist.cpp
+++ b/src/blackmisc/simulation/aircraftmodellist.cpp
@@ -143,7 +143,7 @@ namespace BlackMisc
             });
         }
 
-        CAircraftModelList CAircraftModelList::findWithAircraftDesignator(const QStringList &designators) const
+        CAircraftModelList CAircraftModelList::findWithAircraftDesignator(const QSet<QString> &designators) const
         {
             if (designators.isEmpty()) { return CAircraftModelList(); }
             return this->findBy([ = ](const CAircraftModel & model)
diff --git a/src/blackmisc/simulation/aircraftmodellist.h b/src/blackmisc/simulation/aircraftmodellist.h
index 4491102f2..ed70f5052 100644
--- a/src/blackmisc/simulation/aircraftmodellist.h
+++ b/src/blackmisc/simulation/aircraftmodellist.h
@@ -103,7 +103,7 @@ namespace BlackMisc
             CAircraftModelList findWithAircraftDesignator() const;
 
             //! Models with aircraft ICAO code from list
-            CAircraftModelList findWithAircraftDesignator(const QStringList &designators) const;
+            CAircraftModelList findWithAircraftDesignator(const QSet<QString> &designators) const;
 
             //! Models with a known aircraft ICAO code set
             CAircraftModelList findWithKnownAircraftDesignator() const;