Copter: Heli: ensure inverted flight only in supported modes

ArduCopter/RC_Channel.cpp

@@ -421,7 +421,11 @@ bool RC_Channel_Copter::do_aux_function(const AUX_FUNC ch_option, const AuxSwitc
 #if FRAME_CONFIG == HELI_FRAME
             switch (ch_flag) {
             case AuxSwitchPos::HIGH:
-                copter.attitude_control->set_inverted_flight(true);
+                if (copter.flightmode->allows_inverted()) {
+                    copter.attitude_control->set_inverted_flight(true);
+                } else {
+                    gcs().send_text(MAV_SEVERITY_WARNING, "Inverted flight not available in %s mode", copter.flightmode->name());
+                }
                 break;
             case AuxSwitchPos::MIDDLE:
                 // nothing

ArduCopter/mode.cpp

@@ -457,6 +457,11 @@ void Copter::exit_mode(Mode *&old_flightmode,
             input_manager.set_stab_col_ramp(0.0);
         }
     }
+
+    // Make sure inverted flight is disabled if not supported in the new mode
+    if (!new_flightmode->allows_inverted()) {
+        attitude_control->set_inverted_flight(false);
+    }
 #endif //HELI_FRAME
 }
 

ArduCopter/mode.h

@@ -128,6 +128,10 @@ public:
     virtual bool allows_autotune() const { return false; }
     virtual bool allows_flip() const { return false; }
 
+#if FRAME_CONFIG == HELI_FRAME
+    virtual bool allows_inverted() const { return false; };
+#endif
+
     // return a string for this flightmode
     virtual const char *name() const = 0;
     virtual const char *name4() const = 0;
@@ -1574,6 +1578,8 @@ public:
     bool init(bool ignore_checks) override;
     void run() override;
 
+    bool allows_inverted() const override { return true; };
+
 protected:
 
 private: