Plane: added ACCZ pid tuning

ArduPlane/GCS_Mavlink.cpp

@@ -398,7 +398,12 @@ void Plane::send_pid_tuning(mavlink_channel_t chan)
     if ((g.gcs_pid_mask & TUNING_BITS_LAND) && (flight_stage == AP_Vehicle::FixedWing::FLIGHT_LAND)) {
         send_pid_info(chan, landing.get_pid_info(), PID_TUNING_LANDING, degrees(gyro.z));
     }
-}
+    if (g.gcs_pid_mask & TUNING_BITS_ACCZ && quadplane.in_vtol_mode()) {
+        const Vector3f &accel = ahrs.get_accel_ef();
+        pid_info = &quadplane.pos_control->get_accel_z_pid().get_pid_info();
+        send_pid_info(chan, pid_info, PID_TUNING_ACCZ, -accel.z);
+    }
+ }
 
 uint8_t GCS_MAVLINK_Plane::sysid_my_gcs() const
 {

ArduPlane/defines.h

@@ -123,6 +123,7 @@ enum tuning_pid_bits {
     TUNING_BITS_YAW   = (1 <<  2),
     TUNING_BITS_STEER = (1 <<  3),
     TUNING_BITS_LAND  = (1 <<  4),
+    TUNING_BITS_ACCZ  = (1 <<  5),
     TUNING_BITS_END // dummy just used for static checking
 };