From 11ad9d5a2d03547afb77986d6c496bebbd63b267 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Sun, 5 May 2013 17:09:59 +1000
Subject: [PATCH] Plane: auto-invert pitch control when upside down

this helps to recover when flying inverted, for example when in manual
and hitting the lower altitude geofence
---
 ArduPlane/Attitude.pde | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/ArduPlane/Attitude.pde b/ArduPlane/Attitude.pde
index 8ba9bdb431..a9fae3374d 100644
--- a/ArduPlane/Attitude.pde
+++ b/ArduPlane/Attitude.pde
@@ -105,18 +105,19 @@ static void stabilize_pitch(float speed_scaler)
                                                                     g.flybywire_airspeed_min, g.flybywire_airspeed_max);    
         break;
 
-    default:
+    default: {
         int32_t tempcalc = nav_pitch_cd +
             fabsf(ahrs.roll_sensor * g.kff_pitch_compensation) +
             (g.channel_throttle.servo_out * g.kff_throttle_to_pitch) -
             (ahrs.pitch_sensor - g.pitch_trim_cd);
-        if (inverted_flight) {
+        if (abs(ahrs.roll_sensor) > 9000) {
             // when flying upside down the elevator control is inverted
             tempcalc = -tempcalc;
         }
         g.channel_pitch.servo_out = g.pidServoPitch.get_pid_4500(tempcalc, speed_scaler);
         break;
     }
+    }
 }
 
 /*