Fix altitude change signalling

src/FactSystem/FactControls/FactValueSlider.qml

@@ -56,14 +56,21 @@ Rectangle {
         recalcRelativeIndex()
     }
 
-    Component.onCompleted: valueListView.maximumFlickVelocity = valueListView.maximumFlickVelocity / 2
+    Component.onCompleted: {
+        valueListView.maximumFlickVelocity = valueListView.maximumFlickVelocity / 2
+        reset()
+    }
+
+    Connections {
+        target:         _fact
+        onValueChanged: reset()
+    }
 
     Component {
         id: editDialogComponent
 
         ParameterEditorDialog {
             fact:           _fact
-            onValueChanged: reset()
         }
     }
 
@@ -75,8 +82,6 @@ Rectangle {
         clip:           true
         model:          _model
 
-        Component.onCompleted: reset()
-
         delegate: QGCLabel {
             width:                  _itemWidth
             height:                 _itemHeight

src/MissionManager/SimpleMissionItem.cc

@@ -918,7 +918,7 @@ void SimpleMissionItem::applyNewAltitude(double newAltitude)
             // Leave alone
             break;
         default:
-            _missionItem.setParam7(newAltitude);
+            _altitudeFact.setRawValue(newAltitude);
             break;
         }
     }