Plane: added Q_RTL_MODE parameter

used to switch to VTOL landing on RTL

ArduPlane/ArduPlane.cpp

@@ -748,7 +748,11 @@ void Plane::update_navigation()
         break;
             
     case RTL:
-        if (g.rtl_autoland == 1 &&
+        if (quadplane.available() && quadplane.rtl_mode == 1 &&
+            nav_controller->reached_loiter_target()) {
+            set_mode(QRTL);
+            break;
+        } else if (g.rtl_autoland == 1 &&
             !auto_state.checked_for_autoland &&
             nav_controller->reached_loiter_target() && 
             labs(altitude_error_cm) < 1000) {

ArduPlane/quadplane.cpp

@@ -264,6 +264,13 @@ const AP_Param::GroupInfo QuadPlane::var_info[] = {
     // @User: Standard
     AP_GROUPINFO("RTL_ALT", 35, QuadPlane, qrtl_alt, 15),
 
+    // @Param: RTL_MODE
+    // @DisplayName: VTOL RTL mode
+    // @Description: If this is set to 1 then an RTL will change to QRTL when the loiter target is reached
+    // @Values: 0:Disabled,1:Enabled
+    // @User: Standard
+    AP_GROUPINFO("RTL_MODE", 36, QuadPlane, rtl_mode, 0),
+    
     AP_GROUPEND
 };
 
@@ -1375,6 +1382,8 @@ void QuadPlane::init_qrtl(void)
     plane.do_RTL(plane.home.alt + qrtl_alt*100UL);
     plane.prev_WP_loc = plane.current_loc;
     land.slow_descent = (plane.current_loc.alt > plane.next_WP_loc.alt);
+    land.state = QLAND_POSITION1;
+    land.speed_scale = 0;
 }
 
 /*

ArduPlane/quadplane.h

@@ -199,6 +199,9 @@ private:
     AP_Int8 enable;
     AP_Int8 transition_pitch_max;
 
+    // control if a VTOL RTL will be used
+    AP_Int8 rtl_mode;
+    
     struct {
         AP_Float gain;
         float integrator;