diff --git a/src/blackmisc/aviation/aircraftlights.cpp b/src/blackmisc/aviation/aircraftlights.cpp
index b5465b216..09eb03c1d 100644
--- a/src/blackmisc/aviation/aircraftlights.cpp
+++ b/src/blackmisc/aviation/aircraftlights.cpp
@@ -10,6 +10,7 @@
 #include "blackmisc/aviation/aircraftlights.h"
 #include "blackmisc/stringutils.h"
 #include "blackmisc/variant.h"
+#include <QStringBuilder>
 
 using namespace BlackMisc;
 
@@ -18,6 +19,11 @@ namespace BlackMisc
     namespace Aviation
     {
 
+        CAircraftLights::CAircraftLights(std::nullptr_t null) : m_isNull(true)
+        {
+            Q_UNUSED(null);
+        }
+
         CAircraftLights::CAircraftLights(bool strobeOn, bool landingOn, bool taxiOn, bool beaconOn, bool navOn, bool logoOn)
             : m_strobeOn(strobeOn), m_landingOn(landingOn), m_taxiOn(taxiOn), m_beaconOn(beaconOn), m_navOn(navOn), m_logoOn(logoOn)
         { }
@@ -34,19 +40,12 @@ namespace BlackMisc
 
         QString CAircraftLights::convertToQString(bool /** i18n */) const
         {
-            QString s;
-            s += " strobe: ";
-            s += boolToYesNo(m_strobeOn);
-            s += " landing: ";
-            s += boolToYesNo(m_landingOn);
-            s += " taxi: ";
-            s += boolToYesNo(m_taxiOn);
-            s += " beacon: ";
-            s += boolToYesNo(m_beaconOn);
-            s += " nav: ";
-            s += boolToYesNo(m_navOn);
-            s += " logo: ";
-            s += boolToYesNo(m_logoOn);
+            const QString s = QLatin1Literal("strobe: ") % boolToYesNo(m_strobeOn) %
+                              QLatin1Literal(" landing: ") % boolToYesNo(m_landingOn) %
+                              QLatin1Literal(" taxi: ") % boolToYesNo(m_taxiOn) %
+                              QLatin1Literal(" beacon: ") % boolToYesNo(m_beaconOn) %
+                              QLatin1Literal(" nav: ") % boolToYesNo(m_navOn) %
+                              QLatin1Literal(" logo: ") % boolToYesNo(m_logoOn);
             return s;
         }
 
diff --git a/src/blackmisc/aviation/aircraftlights.h b/src/blackmisc/aviation/aircraftlights.h
index c632f61cc..a2368b4c4 100644
--- a/src/blackmisc/aviation/aircraftlights.h
+++ b/src/blackmisc/aviation/aircraftlights.h
@@ -43,6 +43,9 @@ namespace BlackMisc
             //! Default constructor
             CAircraftLights() = default;
 
+            //! Constructor, init to null
+            CAircraftLights(std::nullptr_t null);
+
             //! Constructor
             CAircraftLights(bool strobeOn, bool landingOn, bool taxiOn, bool beaconOn, bool navOn, bool logoOn);
 
@@ -94,6 +97,9 @@ namespace BlackMisc
             //! All off
             void setAllOff();
 
+            //! Is null;
+            bool isNull() const { return m_isNull; }
+
             //! Returns object with all lights switched on
             static CAircraftLights allLightsOn();
 
@@ -110,6 +116,7 @@ namespace BlackMisc
             bool m_beaconOn = false;
             bool m_navOn = false;
             bool m_logoOn = false;
+            bool m_isNull = false; //!< mark as null
 
             BLACK_METACLASS(
                 CAircraftLights,