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When i fly outside my drone i hit it slightly onto the wall with guards and after that it tilts to left what do i do to fix the problem may it be because its is cold and windy.or because i have to replace the propellers. can you tell me why.and also it wouldn’t lift off because of the tilt i think can u help me by telling me what to do because i don’t know what to do

i suppose one propeller- rotor isn’t working as fast which results in the tilt Update (01/05/2017) or the propeller on the left side is damaged / deformed resulting in lower flow output, compared to the other rotors/ propellers, which makes the tilt