diff --git a/simgear/scene/util/OrthophotoManager.cxx b/simgear/scene/util/OrthophotoManager.cxx
index 4363c55f..14667613 100644
--- a/simgear/scene/util/OrthophotoManager.cxx
+++ b/simgear/scene/util/OrthophotoManager.cxx
@@ -371,6 +371,11 @@ namespace simgear {
         }
     }
 
+    void OrthophotoManager::unregisterAll() {
+        _orthophotos.clear();
+        SG_LOG(SG_TERRAIN, SG_INFO, "Unregistered all orthophotos");
+    }
+
     OrthophotoRef OrthophotoManager::getOrthophoto(const long bucket_idx) {
         if (_orthophotos[bucket_idx]) {
             return _orthophotos[bucket_idx];
diff --git a/simgear/scene/util/OrthophotoManager.hxx b/simgear/scene/util/OrthophotoManager.hxx
index 45b7ba28..950be9cf 100644
--- a/simgear/scene/util/OrthophotoManager.hxx
+++ b/simgear/scene/util/OrthophotoManager.hxx
@@ -91,6 +91,7 @@ namespace simgear {
 
         void registerOrthophoto(const long bucket_idx, const OrthophotoRef& orthophoto);
         void unregisterOrthophoto(const long bucket_idx);
+        void unregisterAll();
 
         /**
          * Get an orthophoto by bucket index