I have a protocol drominum III ap Only had it a few weeks. Not a lot of flight time on it. Was flying fine and then took a pretty good run back and left... being new to flying them, I assumed that the batteries were going low as I have had some stabilization issues when the batteries were going down. So I recharged and replaced them.. no luck... I went thru the calibration protocol as best it is explained in my users manual... which is about as informative as a passed out drunk who witnessed a crime. Basically it said press the calibration button... then take both controllers out and down and then release them..... As you can imagine this did nothing... when I go to take off.. it soars back and left about a foot off the ground and out of control. So my next step was look at the obvious stuff.. no bent props.. they all felt like they were moving freely... however the rear left one..seems to be spinning slightly slower than all the rest.. if u look closely you can see it but it isn't blatantly obvious. This prop issue would explain the direction of the drone when it takes off as if it is spinning slower than it makes sense that the other three would overpower it. And cause the flight issue.... So here is where I am, I'm not sure if there is a more detailed way to calibrate my machine. Or if the problem is the motor is going bad? Simply put I don't have the knowledge to properly diagnos the issue. I'm hoping that with the knowledge here someone has experienced this type issue before and/or can tell me what steps they may take to figure out what would fix the issue. Any thoughts would be appreciated!