Sudden loss of control causing a crash

[foxkeri]

I looked around and saw similar posts.....About a week ago, I was flying my Phantom 2 vision+ around 300 feet in visual range, but after 15 minutes or so, the unit turned 45 degrees towarss the ground and I could hear it FULL SPEED sail down into the trees....as a 50 yr old, it was NOT fun trying to climb the 81 feet to retrieve it lol....I thought it might have been because I recalibrated the IMU but forgot to calibrate the compass before the flight. But, I fixed her all up, calibrated compass successfully and test flew to 15 feet for 10 minutes.....no problem seen....TODAY, I flew it again and because I am so gunshy, I only flew to about 30 feet.......all of a sudden, without warning again, the quad tumbled and crashed, similar to the first instance.....not sure what to do....i called DJI and got an RMA but maybe I can save some grief if I am doing something wrong.......does it sound like a compass error??.....GPS error???. Thanks for any help
ps. I have flown dozens of times without issues at the location this is occurring so its doubtful its magnetic anomoly etc

 

[Fplvert]

Check your motors by hand. They should spin and feel even. You can also check their temperature and see if one is hotter than the others.

It's pretty easy to pick up a bit of debris in a motor that can foul your flight.

 

[RoyVa]

Sometimes when a quad for no known reason does a 45 and comes down it can be due to a bad ESC( motor controler ) if one cuts out the other three rev up try to compensate which speeds it up and does a Fast 45 angle drop. Not usually due to piloting problems. Cause can be a bad Mofit on the ESC board or even a bad solder joint or loose wire. Your probably doing the right thing by sending it in. Be patient repairs are taking from 6-9 weeks door to door. That give you some time to look at you tube videos on the Phantom and get educated as well as pick up a few pointers.