i had problems with this drone flying off on it`s own. i have had it almost a year and have been learning to fly it but i have had 3 fly aways holystone did replace one that i lost when it flew away but this last one flew directly into the ocean. it is a good drone for the money and to learn how to fly , but just be aware it may fly off on you so make sure you can see it. my problems had nothing to do with calibration or cellular interference . i think i will be getting a dji mni 3 pro , no need for a cell phone hookup.