diff --git a/src/Airports/airport.cxx b/src/Airports/airport.cxx
index b5ea39c1a..a565e713a 100644
--- a/src/Airports/airport.cxx
+++ b/src/Airports/airport.cxx
@@ -107,12 +107,6 @@ bool FGAirport::isHeliport() const
   return type() == HELIPORT;
 }
 
-// Static method
-bool FGAirport::isAirportType(FGPositioned* pos)
-{
-  return FGPositioned::isAirportType(pos);
-}
-
 //------------------------------------------------------------------------------
 unsigned int FGAirport::numRunways() const
 {
diff --git a/src/Airports/airport.hxx b/src/Airports/airport.hxx
index bf5832de2..bd145b310 100644
--- a/src/Airports/airport.hxx
+++ b/src/Airports/airport.hxx
@@ -74,10 +74,6 @@ class FGAirport : public FGPositioned
         return mIsClosed;
     }
 
-    // True for the following types: AIRPORT, HELIPORT, SEAPORT.
-    // False for other types, as well as if pos == nullptr.
-    static bool isAirportType(FGPositioned* pos);
-
     virtual const std::string& name() const
     { return _name; }
 
diff --git a/src/GUI/BaseDiagram.cxx b/src/GUI/BaseDiagram.cxx
index fc714e71c..4395ac35d 100644
--- a/src/GUI/BaseDiagram.cxx
+++ b/src/GUI/BaseDiagram.cxx
@@ -254,7 +254,7 @@ void BaseDiagram::splitItems(const FGPositionedList& in, FGPositionedList& navai
 {
     FGPositionedList::const_iterator it = in.begin();
     for (; it != in.end(); ++it) {
-        if (FGAirport::isAirportType(it->ptr())) {
+        if (FGPositioned::isAirportType(it->ptr())) {
             ports.push_back(*it);
         } else {
             navaids.push_back(*it);
@@ -370,7 +370,7 @@ void BaseDiagram::paintNavaid(QPainter* painter, const QTransform& t, const FGPo
 
    // compute label text so we can measure it
     QString label;
-    if (FGAirport::isAirportType(pos.ptr())) {
+    if (FGPositioned::isAirportType(pos.ptr())) {
         label = QString::fromStdString(pos->name());
         label = fixNavaidName(label);
     } else {
@@ -685,7 +685,7 @@ QPixmap BaseDiagram::iconForPositioned(const FGPositionedRef& pos,
     bool small = options.testFlag(SmallIcons);
 
     bool isTowered = false;
-    if (FGAirport::isAirportType(pos)) {
+    if (FGPositioned::isAirportType(pos.ptr())) {
         FGAirport* apt = static_cast<FGAirport*>(pos.ptr());
         isTowered = apt->hasTower();
     }
diff --git a/src/GUI/LocationWidget.cxx b/src/GUI/LocationWidget.cxx
index d59e12f86..94dc9a3af 100644
--- a/src/GUI/LocationWidget.cxx
+++ b/src/GUI/LocationWidget.cxx
@@ -463,7 +463,7 @@ void LocationWidget::restoreLocation(QVariantMap l)
 
     // now we've loaded airport location data (potentially), we can apply
     // more settings
-    if (FGAirport::isAirportType(m_location.ptr())) {
+    if (FGPositioned::isAirportType(m_location.ptr())) {
         if (l.contains("location-apt-runway")) {
             QString runway = l.value("location-apt-runway").toString();
             int index = m_ui->runwayCombo->findText(runway);
@@ -494,7 +494,7 @@ bool LocationWidget::shouldStartPaused() const
         return false; // defaults to on-ground at KSFO
     }
 
-    if (FGAirport::isAirportType(m_location.ptr())) {
+    if (FGPositioned::isAirportType(m_location.ptr())) {
         return m_ui->onFinalCheckbox->isChecked();
     } else {
         // navaid, start paused
@@ -511,7 +511,7 @@ QVariantMap LocationWidget::saveLocation() const
     } else if (m_location) {
         locationSet.insert("location-id", static_cast<qlonglong>(m_location->guid()));
 
-        if (FGAirport::isAirportType(m_location.ptr())) {
+        if (FGPositioned::isAirportType(m_location.ptr())) {
             locationSet.insert("location-on-final", m_ui->onFinalCheckbox->isChecked());
             locationSet.insert("location-apt-final-distance", m_ui->approachDistanceSpin->value());
             if (m_ui->runwayRadio->isChecked()) {
@@ -574,7 +574,7 @@ void LocationWidget::setLocationProperties()
         return;
     }
 
-    if (FGAirport::isAirportType(m_location.ptr())) {
+    if (FGPositioned::isAirportType(m_location.ptr())) {
         FGAirport* apt = static_cast<FGAirport*>(m_location.ptr());
         fgSetString("/sim/presets/airport-id", apt->ident());
         fgSetBool("/sim/presets/on-ground", true);
@@ -685,7 +685,7 @@ void LocationWidget::onCollectConfig()
         return;
     }
 
-    if (FGAirport::isAirportType(m_location.ptr())) {
+    if (FGPositioned::isAirportType(m_location.ptr())) {
         FGAirport* apt = static_cast<FGAirport*>(m_location.ptr());
         m_config->setArg("airport", QString::fromStdString(apt->ident()));
 
@@ -814,7 +814,7 @@ void LocationWidget::onSearchComplete()
 
 void LocationWidget::onLocationChanged()
 {
-    bool locIsAirport = FGAirport::isAirportType(m_location.ptr());
+    bool locIsAirport = FGPositioned::isAirportType(m_location.ptr());
     if (!m_location) {
         onBackToSearch();
         return;
@@ -951,7 +951,7 @@ QString LocationWidget::locationDescription() const
         return tr("No location selected");
     }
 
-    bool locIsAirport = FGAirport::isAirportType(m_location.ptr());
+    bool locIsAirport = FGPositioned::isAirportType(m_location.ptr());
     QString ident = QString::fromStdString(m_location->ident()),
         name = QString::fromStdString(m_location->name());
 
@@ -1009,7 +1009,7 @@ QString LocationWidget::locationDescription() const
 
 void LocationWidget::updateDescription()
 {
-    bool locIsAirport = FGAirport::isAirportType(m_location.ptr());
+    bool locIsAirport = FGPositioned::isAirportType(m_location.ptr());
     if (locIsAirport) {
         FGAirport* apt = static_cast<FGAirport*>(m_location.ptr());