Plane: for better helical landings allow for instant approach stage if previous nav cmd was LOITER_TO_ALT

ArduPlane/ArduPlane.cpp

@@ -944,7 +944,8 @@ void Plane::update_flight_stage(void)
                     bool heading_lined_up = abs(nav_controller->bearing_error_cd()) < 1000 && !nav_controller->data_is_stale();
                     bool on_flight_line = abs(nav_controller->crosstrack_error() < 5) && !nav_controller->data_is_stale();
                     bool below_prev_WP = current_loc.alt < prev_WP_loc.alt;
-                    if ((auto_state.wp_proportion >= 0 && heading_lined_up && on_flight_line) ||
+                    if ((mission.get_prev_nav_cmd_id() == MAV_CMD_NAV_LOITER_TO_ALT) ||
+                        (auto_state.wp_proportion >= 0 && heading_lined_up && on_flight_line) ||
                         (auto_state.wp_proportion > 0.15f && heading_lined_up && below_prev_WP) ||
                         (auto_state.wp_proportion > 0.5f)) {
                         set_flight_stage(AP_SpdHgtControl::FLIGHT_LAND_APPROACH);