Luckily I was able to guide it back home. I followed all guidelines for pre-flight. How do I post the flight logs for someone to look into this?

Check out your TXT flight log to see if it explains what happened. You can upload and view it online here. If you'd like other people to review and comment on your flight log, then please post a link back here after you upload it.

In your case, I would recommend you contact our support and start a case: http://www.dji.com/support Please provide the flight records to them and locate the problem.

Here's a link. No idea why happened. Luckily I kept it in my view so I could try and get it home safely. Anyone have any ideas? No idea what the YAW errors are. Also, can't DJI figure out if there's a compass error or some other error to not send the Drone flying at 40mph? Flying in sport mode made it even harder to get home.

http://www.phantomhelp.com/LogViewer/WAA9T3IVRL3ZRT2MDIRE/

It went crazy over your neighbors house there, maybe there's a strong Wifi interference there.  I had the same type of flight just a couple of days ago here is my log http://www.phantomhelp.com/LogViewer/GWY0EEK4O0P20B7IW4F4/ I am still waiting on some sense of it.  I did however successfully fly without error today.  

Yeah but I’ve flown here 100 times. Never had this problem.

It is a shame that dji cannot handle that Flyaway-problem with the Spark ... So many Spark flyaways

JeyTea Posted at 2018-3-25 02:21
It is a shame that dji cannot handle that Flyaway-problem with the Spark ... So many Spark flyaways

Jey, I think flyaway issues are related to many elements. And many fly away issues are caused by interference and high wind. Therefore, we would recommend users fly in recommended environment. Thanks for your support.

rockmsu Posted at 2018-3-24 18:23
Here's a link. No idea why happened. Luckily I kept it in my view so I could try and get it home safely. Anyone have any ideas? No idea what the YAW errors are. Also, can't DJI figure out if there's a compass error or some other error to not send the Drone flying at 40mph? Flying in sport mode made it even harder to get home.

http://www.phantomhelp.com/LogViewer/WAA9T3IVRL3ZRT2MDIRE/

It isn't in Sport mode, it is in ATTI mode.  ATTI mode is the default when GPS-P mode has failed due to compass or GPS interference.  The pilot has to keep it level or limit the time it is tilted to keep speeds from building up.  The pilot has to arrest speeds by limiting tilt or counter tilting since the autopilot can't without GPS location data and a good compass.

In ATTI mode, centering the sticks will not slow or stop the drone.  You have to provide reverse stick input to stop the momentum.  You should try RATE mode where you can tilt as far as you want and roll the drone inverted.  That's real speed.  RATE mode is available on race drones.

Don't fly over old pool pumps as they will attract your compass when the electro magnets kick in.

Yeah I didn't mean it was in actual sport mode, but it was just starting flying away at that speed. I just don't understand why it needs to move that fast in ATTI mode. If it was moving at normal 15mph speeds to whatever, it would have been a lot easier to corral. It was flying so fast it almost went behind my line of sight where I would have never been able to figure out which direction i was point the sticks to.