src/PlanView/PlanView.qml

@@ -37,6 +37,9 @@ QGCView {
 
     property bool planControlColapsed: false
 
+    ///< This property is used to determine dirty state for prompting on QGC shutdown
+    readonly property bool dirty: _planMasterController.dirty
+
     readonly property int   _decimalPlaces:             8
     readonly property real  _horizontalMargin:          ScreenTools.defaultFontPixelWidth  * 0.5
     readonly property real  _margin:                    ScreenTools.defaultFontPixelHeight * 0.5

src/ui/MainWindowInner.qml

@@ -164,7 +164,7 @@ Item {
         onYes: activeConnectionsCloseDialog.check()
 
         function check() {
-            if (planViewLoader.item && planViewLoader.item.syncNeeded) {
+            if (planViewLoader.item && planViewLoader.item.dirty) {
                 unsavedMissionCloseDialog.open()
             } else {
                 activeConnectionsCloseDialog.check()