From e55350a5d657f41052fe328b947ec1e3ab5b9fa1 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <andrew@tridgell.net>
Date: Mon, 16 Mar 2015 10:59:40 +1100
Subject: [PATCH] Plane: added crash detection in autoland

if we are no longer flying then flare, which turns off the motor

This is based on work by Tom Pittenger
---
 ArduPlane/landing.pde | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/ArduPlane/landing.pde b/ArduPlane/landing.pde
index f7f9cef21f..13ee02d1e7 100644
--- a/ArduPlane/landing.pde
+++ b/ArduPlane/landing.pde
@@ -52,11 +52,16 @@ static bool verify_land()
     */
     if (height <= g.land_flare_alt ||
         height <= auto_state.land_sink_rate * aparm.land_flare_sec ||
-        (!rangefinder_state.in_range && location_passed_point(current_loc, prev_WP_loc, next_WP_loc))) {
+        (!rangefinder_state.in_range && location_passed_point(current_loc, prev_WP_loc, next_WP_loc)) ||
+        (fabsf(auto_state.land_sink_rate) < 0.2f && !is_flying())) {
 
         if (!auto_state.land_complete) {
-            gcs_send_text_fmt(PSTR("Flare %.1fm sink=%.2f speed=%.1f"), 
-                              height, auto_state.land_sink_rate, gps.ground_speed());
+            if (!is_flying()) {
+                gcs_send_text_fmt(PSTR("Flare crash detected: speed=%.1f"), gps.ground_speed());
+            } else {
+                gcs_send_text_fmt(PSTR("Flare %.1fm sink=%.2f speed=%.1f"), 
+                                  height, auto_state.land_sink_rate, gps.ground_speed());
+            }
         }
         auto_state.land_complete = true;