diff --git a/src/Main/bfi.cxx b/src/Main/bfi.cxx
index 13f1b1833..14b66bc9c 100644
--- a/src/Main/bfi.cxx
+++ b/src/Main/bfi.cxx
@@ -37,6 +37,7 @@
 #include <Aircraft/aircraft.hxx>
 #include <Controls/controls.hxx>
 #include <Autopilot/autopilot.hxx>
+#include <Scenery/scenery.hxx>
 #include <Time/fg_time.hxx>
 #include <Time/light.hxx>
 #include <Cockpit/radiostack.hxx>
@@ -307,6 +308,18 @@ FGBFI::getAltitude ()
 }
 
 
+
+/**
+ * Return the current altitude in above the terrain.
+ */
+double
+FGBFI::getAGL ()
+{
+  return current_aircraft.fdm_state->get_Altitude()
+	 - scenery.cur_elev * METER_TO_FEET;
+}
+
+
 /**
  * Set the current altitude in feet.
  */
diff --git a/src/Main/bfi.hxx b/src/Main/bfi.hxx
index c295823d3..7fb7c6d27 100644
--- a/src/Main/bfi.hxx
+++ b/src/Main/bfi.hxx
@@ -65,6 +65,7 @@ public:
   static double getLatitude ();
   static double getLongitude ();
   static double getAltitude ();
+  static double getAGL ();
 
   static void setLatitude (double latitude);
   static void setLongitude (double longitude);