From e05c7b3367867c12f6f8d9496b5087b0343a48aa Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Fri, 10 Jun 2016 17:47:32 +1000
Subject: [PATCH] Plane: check if terrain following is enabled in AGL
 calculation

---
 ArduPlane/altitude.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ArduPlane/altitude.cpp b/ArduPlane/altitude.cpp
index 05cff9d781..5f47316030 100644
--- a/ArduPlane/altitude.cpp
+++ b/ArduPlane/altitude.cpp
@@ -145,7 +145,9 @@ float Plane::relative_ground_altitude(bool use_rangefinder_if_available)
 
 #if AP_TERRAIN_AVAILABLE
     float altitude;
-    if (terrain.status() == AP_Terrain::TerrainStatusOK && terrain.height_above_terrain(altitude, true)) {
+    if (target_altitude.terrain_following &&
+        terrain.status() == AP_Terrain::TerrainStatusOK &&
+        terrain.height_above_terrain(altitude, true)) {
         return altitude;
     }
 #endif