Hello I recently built a f450 Quadcopter. I am using APM 2.8 with 3.2.1 firmware . The problem that I am facing is that when I fly the quad very close to me it flies great but when I taken the drone to certain height say 100m it flips to one side . It seems that two motor are completely stopped and they are stopped for only 2 seconds because when I put the throttle to 100 the quad can be controlled again. But this flip occurs in again and again which might be dangerous. Plz tell me is it the problem of faulty motor, faulty propeller , faulty esc or is it a APM flight controller problem. Plz help I am very worried. I am attaching two log files also plz analyse both of them. Thanks for your help in advance.