Fixed wing landing problem


We built a fixed wing UAV with Pixhawk 4. It had done successful flights so far. But last two missions did not make sense. The UAV was handlaunched, flew to waypoints then went for landing pattern. In landing pattern it enters loiter and then keeps circling in loiter and descending and landing there instead of entering the landing approach and coming in to landing area properly. So it basically just gets stuck in loiter and descends while loitering. We had crashed twice this way. Any idea what could be going wrong and how to fix it?

Any help would be greated appreciated.


Can you upload the log/post a flight review link?

Mission file too if you have it.


all my last flights have had these problems. first few flights were perfect and then the vehicle does something like turns and descends till crash landing itself. i am using a brand new pixhawk 4 controller.